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Students can Download Chapter 2 Plant Kingdom Notes, Plus One Botany Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Botany Notes Chapter 2 Plant Kingdom

Different Plant Groups:

1. Algae
2. Bryophytes
3. Pteridophytes
4. Gymnosperms
5. Angiosperms.

Types of classification:
1. Artificial system of classification:
The systems of classification based morphological characters such as habit, colour, number and shape of leaves, etc i.e based on vegetative characters or on the androecium structure. eg: Linnaeus classification.

2. Natural system of classification:
The systems of classification based on not only the external features, but also internal features, like ultrastructure, anatomy, embryology and phytochemistry. eg: George Bentham and Joseph Dalton Hookers classification

3. Phylogenetic system of classification:
The systems of classification based on evolutionary relationships between the various organisms. eg: Englerand prantl.

Taxonomy in modern approach:
1. Numerical Taxonomy
In this, number and codes are assigned to all the characters and the data are processed. This is carried out using computers based on all observable characteristics.

2. Cytotaxonomy:
In this cytological information like chromosome number, structure and behavior are considered.

3. Chemotaxonomy:
It is based on chemical constituents of the plant.

1. Algae:
Characterestic features:
Algae are chlorophyll-bearing, simple, thalloid, autotrophic and largely aquatic (both fresh water and marine) organisms.

Size of algal forms:

1. Microscopic unicellular forms eg Chlamydomonas,
2. Colonial forms eg Volvox
3. Filamentous forms eg Ulothrix and Spirogyra.

Reproduction:
1. Vegetative reproduction:
It occures by fragmentation. Each fragment develops into a thallus. .

2. Asexual reproduction:
lt occures by the production zoospores. They are flagellated (motile) and on germination gives rise to new plants.

3. Sexual reproduction:
It takes place through fusion of two gametes.

(A) Isogamous:
These gametes are flagellated and similar in size (as in Chlamydomonas) or non-flagellated (non-motile) but similar in size (as in Spirogyra).

(B) Anisogamous:
It is the fusion of two gametes dissimilar in size. eg: species of Chlamydomonas

(C) Oogamous:
It is the fusion between one large, non-motile (static) female gamete and a smaller, motile male gamete eg: Volvox, Fucus.

Economic imoportance:

1. Half of the total carbon dioxide fixation on earth is carried out by algae through photosynthesis.
2. Many species of Porphyra, Laminaria and Sargassum are among the 70 species of marine algae used as food.
3. Certain marine brown and red algae produce large amounts of hydrocolloids (water holding substances), eg: algin (brown algae) and carrageen (red algae) are used commercially.
4. Agar obtained from Gelidium and Gracilaria are used to grow microbes and in preparations of ice-creams and jellies.
5. Chlorella and Spirullina are unicellular algae, rich in proteins and are used as food by space travellers.

Three main classes of algae:

Chlorophyceae (Green algae):
Salient features:

1. The plant body may be unicellular, colonial or filamentous. The dominant green pigments are chlorophyll a and b.
2. The chloroplasts may be discoid, plate-like, reticulate, cup-shaped, spiral or ribbon-shaped in different species.
3. The storage bodies called pyrenoids located in the chloroplasts. Pyrenoids contain protein besides starch.
4. Green algae have a rigid cell wall made of an inner layer of cellulose and an outer layer of pectose.
5. Vegetative reproduction usually takes place by fragmentation.
6. Asexual reproduction is by flagellated zoospores produced in zoosporangia.
7. The sexual reproduction may be isogamous, anisogamous or oogamous.

eg: Chlamydomonas, Volvox, Ulothrix, Spirogyra and Chara.

Phaeophyceae (Brown algae):
Salient features:

1. They are mainly found in marine habitats.
2. The size of plant body range from simple branched, filamentous forms (l=ctocarpus) to profusely branched forms such as kelDs (height 100 metres).
3. They possess chlorophyll a, c, carotenoids and xanthophylls. Fucoxanthin is present in large amount.
4. Food is stored as complex carbohydrates in the form of laminarin or mannitol.
5. The vegetative cells with cellulosic wall is covered on the outside by a gelatinous coating of algin.
6. The plant body is attached to the substratum by a holdfast, and has a stalk, the stipe and leaf like photosynthetic organ-the frond.
7. Vegetative reproduction takes place by fragmentation.
8. Asexual reproduction is by biflagellate zoospores that are pear-shaped and have tyvo unequal laterally attached flagella.
9. Sexual reproduction may be isogamous, anisogamous or oogamous.
10. The gametes are pyriform (pear-shaped) and bear two laterally attached flagella.

eg: Ectocarpus, Dictyota, Laminaria, Sargassum and Fucus.

Rhodophyceae(Red algae):
Salient features:

1. Majority are marine and found in the warmer areas.
2. The red thalli of most of the red algae are multicellular. The chlorophyll pigments are chi a,chi d.
3. The dominant red pigment is r-phycoerythrin.
4. The food is stored as floridean starch similar to amylopectin and glycogen in structure.
5. The red algae usually reproduce vegetatively by fragmentation.
6. They reproduce asexually by non-motile spores and sexually by non-motile gametes.
7. Sexual reproduction is oogamous and accompanied by complex post fertilisation developments.

eg: Polysiphonia, Porphyra, Gracilaria and Gelidium.

2. Bryophytes:
Amphibians of the plant kingdom?
Because these plants are found in damp, humid and shaded localities and dependent on water for sexual reproduction.
Salient features:

• Thallus is prostrate or erect, and attached to the substratum by unicellular or multicellular rhizoids.
• They lack true roots, stem or leaves.
• The main plant body of the bryophyte is haploid. It produces gametes, hence is called a gametophyte.
• The male sex organ is multicellular antheridium. They produce biflagellate antherozoids.
• The female sex organ called archegonium it is flask-shaped and produces a single egg.

Sexual reproduction:
Antherozoid moves through water they come in contact with archegonium and fuses with the egg to produce the zygote. Zygotes produce a multicellular body called a sporophyte.

What is the nature and development of sporophytes of bryophytes?
The sporophyte is not free-living but attached to the photosynthetic gametophyte Some cells of the sporophyte undergo reduction division (meiosis) to produce haploid spores. These spores germinate to produce gametophyte.

Economic importance:

1. They play an important role in plant succession on bare rocks/soil. They decompose rocks making the substrate suitable for the growth of higher plants.
2. Some mosses provide food for herbaceous mammals, birds and other animals.
3. Sphagnum, a moss, provide peat that is used as fuel, and because of their capacity to hold water as packing material for trans-shipment of living material.
4. Mosses form dense mats on the soil hence it prevents soil erosion.

The bryophytes are divided into liverworts and mosses.
Liverworts:
Growing locality:
The liverworts grow in moist, shady habitats such as banks of streams, marshy ground, damp soil, bark of trees and deep in the woods.

What is nature of plant body?
The plant body of a liverwort is thalloid, eg: Marchantia.

Features of Gemmae and its development:
Gemmae are green, multicellular, asexual buds. It is detached from the parent body and germinate to form new individuals.

Structure of sporophvte and spore development:
The sporophyte is differentiated into a foot, seta and capsule. After meiosis, spores are produced within the capsule. These spores germinate to form free-living gametophytes.

Mosses:
Spore germination and protonema:
In the life cycle of bryophytes, spore germinate and forms a creeping, green, branched and a filamentous stage called protonema. The second stage is the leafy stage, which develops from the secondary protonema as a lateral bud.

Features of leafy stage:
They consists of spirally arranged leaves and multicellular branched rhizoids. This stage bears the sex organs. It is the true gametophyte.

Vegetative reproduction:
It takes place by fragmentation and budding in the secondary protonema.

Sexual reproduction.
In sexual reproduction, the sex organs are antheridia and archegonia. After fertilisation, the zygote develops into a sporophyte, consisting of a foot, seta and capsule.

Which group of brvophvte shows well developed sporophyte?
The sporophyte in mosses is more elaborate than that in liverworts. The mosses have an elaborate mechanism of spore dispersal. eg: Funaria, Polytrichum and Sphagnum

3. Pteridophytes:
Salient features:

1. The Pteridophytes are the first terrestrial plants that possess vascular tissues – xylem and phloem. This group includes horsetails and ferns.
2. They are frequently grown as ornamentals.
3. The pteridophytes are found in cool, damp, shady places and require water for fertilisation .
4. The main plant body is a sporophyte which is differentiated into true root, stem and leaves .
5. The leaves in pteridophyta are small (microphylls) as in Selaginella or large (macrophylls) as in ferns.
6. The sporophytes bear sporangia by leaf-like appendages called sporophylls.
7. In some cases sporophylls forms distinct compact structures called strobili or cones (Selaginella, Equisetum).
8. The sporangia produce spores by meiosis in spore mother cells.
9. The spores germinate to give rise multicellular, free-living, photosynthetic thalloid gametophytes called prothallus.
10. The gametophytes bear male and female sex organs called antheridia and archegonia, respectively.

Sexual reproduction:
How do the sporophytes form?
Water is required for transfer of antherozoids to the mouth of archegonium. Fusion of male gamete with the egg present in the archegonium result in the formation of zygote. It undergoes divisions and forms multicellular well-differentiated sporophyte which is the dominant phase of the pteridophytes.

Distiquish between homosporous and heterosporous type or Heterospory is considered as important step in evolution why?
Majority members produce spores are of similar kinds such plants are called homosporous. Few members produce two kinds of spores, macro (large) and micro (small) spores, are-known as heterosporous. eg: Selaginella and Salvinia.

The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. The development of the zygotes into young embryos take place within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution..
The pteridophytes are further classified into four classes:

1. Psilopsida(Psilotum)
2. Lycopsida (Selaginella, Lycopodium)
3. Sphenopsida (Equisetum
4. Pteropsida (Dryopteris, Pteris, Adiantum).

4. Gymnosperms:
Salient features:
1. They are naked seed bearing plants in which the ovules are not enclosed by ovary wall and remain exposed.

2. Tap roots have fungal association in the form of mycorrhiza (Pinus), while in some others (Cycas) small specialized roots called coralloid roots are associated with N2-fixing cyanobacteria.

3. The stems are unbranched (Cycas) or branched (Pinus, Cedrus).

4. The leaves are well-adapted to withstand extremes of temperature, humid ity and wind. .
How can conifers adapt to live in extreme temperature condition or water deficient soil?

• In conifers, the needle-like leaves that reduce the surface area. .
• Thick cuticle and
• sunken stomata

All these characters help to reduce water loss.

5. In Cycas the pinnate leaves persist for a few years.

6. They produce haploid microspores and megaspores i.e heterosporous. These spores are produced within sporangia that are borne omsporophylls which are arranged spirally along an axis to form compact strobili or cones. The strobili bearing microsporophylls and microsporangia are called male strobili.

The microspores develop into a male gametophytic generation. This reduced gametophyte is called a pollen grain. The pollen grain is released from the microsporangium. The cones bearing megasporophylls with ovules or megasporangia are called female strobili.

7. The male or female cones borne on the same tree (Pinus) or on different trees (Cycas).

Development of female qametophyte:
The ovules are borne on megasporophylls that contains nucellus. The megaspore mother cell of nucellus divides meiotically to form four megaspores. One of the megaspores enclosed within the megasporangium (nucellus) develops into a multicellular female gametophyte that bears two or more archegonia
1. The male and the female gametophytes remain within the sporangia retained on the sporophytes.

2. The pollen tube carrying the male gametes grows towards archegonia in the ovules and discharge their contents near the mouth of the archegonia. Following fertilisation, zygote develops into an embryo and the ovules into seeds. These seeds are not covered.

Which is the tallest tree species in world?
Giant redwood tree Sequoia is one of the tallest tree species.

5. Angiosperms (Flowering plants):
Salient features:
1. In this the seeds are enclosed by fruits.
Range of size:

• Microscopic-Wolfie
• Tall trees- Eucalyptus(o\ier 100 metres).

2. Two classes in angiosperms:

• Dicotyledons (two cotyledons in their seeds)
• Monocotyledons (one cotyledon)

3. The male sex organs in a flower is the stamen. Each stamen consists of a slender filament with an anther at the tip. The anthers produce pollen grains.

4. The female sex organs is the pistil or the carpel. Pistil consists of an ovary enclosing one to many ovules. The highly reduced female gametophytes (embryosacs) found within ovules.

5. Typical embryosac is 7 celled and 8 nucleate Each embryo-sac has a three-celled egg apparatus – one egg cell and two synergids, three antipodal cells and two polar nuclei. The polar nuclei eventually fuse to produce a diploid secondary nucleus. The cells of an embryo-sac is haploid.

Pollination and pollen tube:
Pollen grain from anther falls on the stigma of a pistil is termed as pollination. The pollen grains germinate and produce pollen tubes that reach the ovule. The pollen tubes enter the embryo-sac where two male gametes are discharged.

Double fertilization:
What are the products and process of double fertilization?
One of the male gametes fuses with the egg cell to form a zygote. This is called syngamy. The other male gamete fuses with the diploid secondary nucleus to produce the triploid primary endosperm nucleus (PEN). This is called Triple fusion. Because of the involvement of two fusions, this event is termed as double fertilization.

Post fertilization changes and significance of edosperm:
The zygote develops into an embryo and the PEN develops into endosperm which provides nourishment to the developing embryo. The synergids and antipodals degenerate after fertilisation. After fertilization ovules develop into seeds and the ovaries develop into fruits.

Plant Life Cycles And Alternation Of Generations:
In plants, both haploid and diploid cells can divide by mitosis. This ability leads to the formation of different plant bodies – haploid and diploid.

1. Haplontic life cycle:
How do gametophyte forms?
Meiosis in the zygote results in the formation of haploid spores. Then, these spores are divide mitotically and form the gametophyte.

What is the nature of sporophyte and gametophyte?
Sporophytic generation is represented only by the one-celled zygote. The dominant, photosynthetic phase is the free-living gametophyte.

2. Diplontic life cycle What is the nature of sporophyte and qametophyte?
The diploid sporophyte is the dominant, photosynthetic, independent phase of the plant. The gametophytic phase is represented by the single to few-celled haploid gametophyte. eg: gymnosperms and angiosperms.

3. Haplo-diplontic:
It is an intermediate condition in which both phases are multicellular and often free-living.

What is the nature of both sporophyte and gametophyte?
A dominant, independent, photosynthetic phase is represented by a haploid gametophyte and it alternates with the short lived multicelluler sporophyte dependent on the gametophyte. eg: Bryophytes and pteridophytes.

Algae in haplo-diplontic and diplontic stage:

• Ectocarpus, Polysiphonia and kelps are haplo-diplontic.
• Fucus, an alga is diplontic.

Students can Download Chapter 4 Biomolecules Notes, Plus One Zoology Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Zoology Notes Chapter 4 Biomolecules

How To Analyse Chemical Composition?
Take any living tissue (a vegetable or a piece of liver, etc.) and grind it in trichloroacetic acid (Cl₃CCOOH) using a mortar and a pestle. The thick slurry is formed. Then it is passed through a cheese cloth or cotton getting two fractions.

1. Acid soluble fraction (Filtrate)
2. Acid-insoluble fraction.
   • All the carbon compounds from living tissues are called ‘biomolecules’.
   • The tissue is fully burnt, all the carbon compounds are oxidised to gaseous form (C02, water vapour) and are removed.
   • The remaining is called ‘ash’. It contains inorganic elements (like calcium, magnesium etc).
   • Inorganic compounds like sulphate, phosphate, etc., are also seen in the acid-soluble fraction.

Organic compounds under biological view are classified into

• Amino acids:
• Nucleotide bases
• Fatty acids etc.

Amino acids:

1. They are organic compounds containing four substituent groups occupying the four valency positions.
2. These are hydrogen, carboxyl group, amino group and a variable group designated as R group.

Based on the nature of R group there are many amino acids. However, those which occur in proteins are only of twenty one types.
The R group may be

• Hydrogen (the amino acid is called glycine)
• A methyl group (alanine)
• Hydroxyl methyl (serine), etc.

Based on number of amino and carboxyl groups, there are

A particular property of amino acids is due to ionizable nature of —NH₂ and —COOH groups

Fatty acid:
It has a carboxyl group attached to an R group.
The R group could be

1. A methyl (—CH₂)
2. Ethyl (—C₂H₅)

Carbon number varies in different fatty acids:

• Palmitic acid – 16 carbon atoms
• Arachidonic acid – 20 carbon atoms

Fatty acids are

• Lipids possess both glycerol and fatty acids.
• They are monoglycerides, or diglycerides or triglycerides.
• These are also called fats and oils based on melting point. Oils have lower melting point eg: gingely oil.
• Some lipids have phosphorous, they are called phospholipids. They are found in cell membrane. eg: lecithin

Nitrogen bases:

• They are (heterocyclic rings) adenine, guanine, cytosine, uracil, and thymine
• If they are found attached to a sugar, they are called nucleosides.
• If a phosphate group is found esterified to the sugar, they are called nucleotides.
• Nucleic acids like DNA and RNA consist of nucleotides only.

Diagrammatic representation of small molecular weight organic compounds in living tissues.

Primary And Secondary Metabolites:
Primary metabolites:
Organic compounds such as amino acids, sugars, etc.are belongs to primary metabolites. Primary metabolites play important role in normal physiologial processes.

Secondary metabolites:
When analyse plant, fungal and microbial cells the alkaloides, flavonoides, rubber, essential oils, antibiotics, coloured pigments, scents, gums, spices etc are found. These are called secondary metabolites. Many of them are useful to ‘human welfare’ (eg: rubber, drugs, spices, scents and pigments).

Biomacromolecules:
The acid insoluble fraction, has only four types of organic compounds i.e., proteins, nucleic acids, polysaccharides and lipids. These compounds, except lipids, have molecularweights in the range often thousand daltons and above.

Lipids, whose molecularweights do not exceed 800 Da, come under acid insoluble fraction. Hence Lipids are not macromolecules.

Biomicromolecules and biomacromolecules:
Molecular weights less than one thousand dalton are referred to as micromolecules or simply biomolecules while those which are found in the acid insoluble fraction are called macromolecules or biomacromolecules.

Proteins:
Proteins (heteropolymer)are linear chains of amino acids linked by peptide bonds i.e polymer of amino acids There are 21 types of amino acids (eg: alanine, cysteine, proline, tryptophan, lysine, etc.)
Some Proteins and their Function:

• Dietary proteins are the source of essential amino acids.
• Therefore, amino acids are essential or non-essential.
• Essential amino acids obtained through food.

Proteins carry out many functions in living organisms:

1. some transport nutrients across cell membrane
2. some fight infectious organisms
3. Collagen is the most abundant protein in animal world and
4. Ribulose bisphosphate Carboxylase – Oxygenase (RUBISCO) is the most abundant protein in the biosphere.

POLYSACCHARIDES
1. Polysaccharides are long chains of sugars.

2. Forexamplecellulose(homopolymer)is a polysaccharide consist of only one type of monosaccharide i.e. glucose.

3. Starch is store house of energy in plant tissues but animals have glycogen as energy source.

4. Inulin is a polymer of fructose.

5. In a polysaccharide eg glycogen, the right end is called the reducing end and the left end is called the non reducing end.

Starch forms helical secondary structures:

1. Starch can hold l₂ molecules in the helical portion. This reaction product blue in colour.
2. Cellulose does not contain complex helices and hence cannot hold l₂.
3. Cotton fibre is cellulose
4. The complex polysaccharides have as building blocks such as amino-sugars (eg: glucosamine, N— acetyl galactosamine, etc.).
5. Exoskeletons of arthropods have a complex polysaccharide called chitin (heteropolymers)

Nucleic Acids:
Nucleic acids are the another macromolecule that found in the acid insoluble fraction of living tissues. For nucleic acids, the building block is a nucleotide.

Components of nucleic acid:

1. Heterocyclic compound(adenine, guanine, uracil, cytosine and thymine).
2. Monosaccharide and
3. A phosphoric acid or phosphate.

The sugar found in polynucleotides is either ribose (a monosaccharide pentose) or 2’ deoxyribose.

Nature of pentose sugar in DNA and RNA:
A nucleic acid containing deoxyribose is called deoxyribonucleic acid (DNA) while that which contains ribose is called ribonucleic acid (RNA).

Structure Of Proteins (Proteins are heteropolymers containing many amino acids):
Primary structure:
The sequence of amino acid in which the left end represented by the first amino acid (N— terminal amino acid )the right end represented by the last amino acid (C— terminal amino acid). This sequence forms linear structure. It is called the primary structure.

Primary structure of a portion of a hypothetical protein. N and C refer to the two termini of every protein. Single letter codes and three letter abbreviations for amino acids are also indicated.

Secondary structure:
The primary structure have rigid rod like appearance which is folded in the form of a helix (similar to a revolving staircase). It appears as right handed helices. It is called the secondary structure. Secondary structures exhibited by DNA is the Watson-Crick model. In this DNA exists as a double helix.

Tertiary structure:
The long protein chain is also folded upon itself like a hollow wollen ball, it called the tertiary structure. This gives us a 3-dimensional view of a protein. Tertiary structure is necessary for the many biological activities of proteins.

Quaternary structure:
Some proteins are assembled by more than one polypeptide chains .This is called the quaternary structure Adult human haemoglobin consists of 4 subunits. Two of these are identical to each other. Hence, two subunits are of a type and two subunits are of p type together constitute the human haemoglobin (Hb).

Nature Of bond linking Monomers In A Polymer:
1. Peptide bond:
In a protein, amino acids are linked by a peptide bond which is formed when the carboxyl (—COOH) group of one amino acid reacts with the amino (-NH₂) group of the next amino acid with the elimination of a water.

2. Glvcosidic bond:
In a polysaccharide the individual monosaccharides are linked by a glycosidic bond. This bond is also formed by dehydration.

3. Phosphodiester Bond:
In a nucleic acid a phosphate moiety links the 3′-carbon of one sugar of one nucleotide to the 5′-carbon of the sugar of the succeeding nucleotide. The bond between the phosphate and hydroxyl group of sugar is called phosphodiester bond

DNA Structure:

1. The two strands of polynucleotides are antiparallel i.e., run in the opposite direction.
2. The backbone is formed by the sugar-phosphate-sugar chain.
3. The nitrogen bases are A and G of one strand base pairs with T and C, respectively
4. There are two hydrogen bonds between A and T but three hydrogen bonds are present between G and C.
5. Each strand appears like a helical staircase.
6. At each step of ascent, the strand turns 36°.
7. One full turn of the helical strand have ten steps or ten base pairs.
8. The pitch is 34A°. The distance between each base pairs is 3.4A°.
9. This form of DNA is called B-DNA.

Dynamic State Of Body Constituents – Concept Of Metabolism:
Biomolecules are constantly being changed into some other biomolecules and also made from some other biomolecules. This is called turn over. This breaking and making is through chemical reactions constantly occurring in living organisms called as metabolism.

Metabolic reactions and transformation of biomolecules:

1. removal of CO₂ from amino acids making an amino acid into an amine,
2. removal of amino group in a nucleotide base and
3. hydrolysis of a glycosidic bond in a disaccharide
   • Majority of these metabolic reactions are always linked to some other reactions. This series of linked reactions called metabolic pathways.
   • These metabolic pathways are similar to the automobile traffic in a city.
   • Another feature of these metabolic reactions is that every chemical reaction is a catalysed reaction.
   • The catalysts which hasten the rate of a given metabolic conversation are also proteins. These proteins with catalytic power are named enzymes.

Metabolic Basis For Living:

1. Metabolic pathways involves two processes The synthesis step is called anabolic pathways. The degradation step is called catabolic pathways.
2. Catabolic pathways lead to the release of energy.
3. For example, when glucose is degraded to lactic acid in our skeletal muscle, energy is liberated which stored in the form of chemical bonds, when needed, this bond energy is utilized.

Which is the energy currency of a cell?

• The energy currency in living systems is the bond energy in a chemical called adenosine triphosphate (ATP).

The Living State:

• All living organisms exist in a steady-state characterised by concentrations of each of these biomolecules.
• These biomolecules are in a metabolic flux. Any chemical or physical process moves spontaneously to equilibrium.
• The steady state is a non-equilibirium state. The systems at equilibrium cannot perform work. As living organisms work continuously, they cannot afford to reach equilibrium.

Metabolism provides a mechanism for the production of energy. Hence the living state and metabolism are synonymous. Without metabolism there cannot be a living state.

Enzymes:

Enzvme activity:

• The tertiary structure is biologically active, an active site of an enzyme is a crevice or pocket into which the substrate fits.
• Thus enzymes, through their active site, catalyse reactions at a high rate.
• Enzymes are damaged at high temperatures (say above 40°C).
• Some enzymes isolated from organisms who normally live under extremely high temperatures (eg: hot vents and sulphur springs), are stable and retain their catalytic power even at high temperatures (upto 80° – 90°C).
• Thermal stability is thus an important quality of such enzymes isolated from thermophilic organisms.

Chemical Reactions:
Chemical compounds undergo two types of changes.
1. Physical change:
It involves the change in shape without breaking of bonds. eg: when ice melts into water, or when water becomes a vapour.

2. Chemical reaction/change:
When bonds are broken and new bonds are formed during transformation, this will be called a chemical reaction.Eg. Hydrolysis of starch into glucose is an organic chemical reaction. Rate of a physical or chemical process refers to the amount of product formed per unit time.

Role of enzvme in the rate of chemical reaction:
In the absence of any enzyme this reaction is very slow, with about 200 molecules of H₂CO₃ being formed in an hour. But using an carbonic anhydrase, the reaction speeds dramatically with about 600,000 molecules being formed every second.

The enzyme has accelerated the reaction rate by about 10 million times. A multistep chemical reaction, when each of the steps is catalysed by the same enzyme complex or different enzymes, is called a metabolic pathway.

1. In glycolysis glucose becomes pyruvic acid through ten different enzyme catalysed metabolic reactions.
2. Under normal aerobic conditions, pyruvic acid is formed.
3. In yeast, during fermentation, the same pathway leads to the production of ethanol (alcohol).
4. In our skeletal muscle, under anaerobic conditions, lactic acid is formed.

How do Enzymes bring about High Rates of Chemical Conversions?
The chemical which is converted into a product is called a ‘substrate’. Hence enzymes, i.e. proteins with three dimensional structures including an ‘active site’ convert a substrate (S) into a product (P).

What is the transition state?
During the state where substrate is bound to the enzyme active site, a new structure of the substrate called unstable transition state is formed. Then the bond breaking/making is completed, the product is released from the active site. The y-axis represents the potential energy content.

The x-axis represents the progression of the structural transformation or states through the ‘transition state’. If ‘P’ is at a lower level than ‘S’, the reaction is an exothermic reaction one need not to supply energy (by heating) in order to form the product.

However, whether it is an exothermic or spontaneous reaction or an endothermic or energy requiring reaction, the ‘S’ has to go through a much higher energy state or transition state. The difference in average energy content of ‘S’ from that of this transition state is called ‘activation energy’.

Enzymes bring down energy barrier making the transition of ‘S’ to ‘P’ more easy. Catalysed reactions proceed at rates faster than that of uncatalysed ones.

Nature of Enzyme Action:

Each enzyme (E) has a substrate (S) binding site in its molecule so that a highly reactive enzyme-substrate complex (ES) is produced. This complex is short-lived and dissociates into its products.

The catalytic cycle of an enzyme action can be described in the following steps:

Factors Affecting Enzyme Activity:

The activity of an enzyme can be affected by temperature, pH, change in substrate concentration.
1. Temperature and pH:
Each enzyme shows its highest activity at a particular temperature and pH called the optimum temperature and optimum pH. Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat.

2. Concentration of Substrate:
With the increase in substrate concentration, the velocity of the enzymatic reaction rises at first. The reaction ultimately reaches a maximum velocity (V_max) which is not increased by further rise in concentration of the substrate because the enzyme molecules are saturated there are no free enzyme molecules to bind with the additional substrate molecules

Enzyme inhibition:
When the binding of the chemical shuts off enzyme activity, the process is called inhibition and the chemical is called an inhibitor. When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor. eg: Inhibition of succinic dehydrogenase by malonate which closely resembles the substrate succinate in structure. Such competitive inhibitors are often used in the control of bacterial pathogens.

Classification and Nomenclature of Enzymes:
Enzymes are divided into 6 classes.
1. Oxidoreductases/dehvdroaenases:
Enzymes which catalyse oxidoreduction between two substrates S and S’ eg:

2. Transferases:
Enzymes catalysing a transfer of a group, G (other than hydrogen) between a pair of substrate S and S’ eg:
\(\mathbf{S}-\mathbf{G}+\mathbf{S}^{‘} \longrightarrow \mathbf{S}+\mathbf{S}^{‘}-\mathbf{G}\)

3. Hydrolases:
Enzymes catalysing hydrolysis of ester, ether, peptide, glycosidic, C – C, C – halide or P – N bonds.

4. Lyases:
Enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds.

5. Isomerases:
Includes all enzymes catalysing inter-conversion of optical, geometric or positional isomers.

6. Lyases:
Enzymes catalysing the linking together of 2 compounds, eg: enzymes which catalyse joining of C – O, C – S, C – N, P – O etc. bonds.

Co-factors:
Enzymes are composed of one or several polypeptide chains and non-protein constituents called cofactors. They are bound to the enzyme to make the enzyme catalytically active. The protein part of the enzymes is called the apoenzyme.
Three kinds of cofactors are

1. prosthetic groups
2. co-enzymes
3. Metal ions.

1. Prosthetic groups:
They are organic compounds that are tightly bound to the apoenzyme. For example, in peroxidase and catalase, which catalyze the breakdown of hydrogen peroxide to water and oxygen. Haem is the prosthetic group and it is a part of the active site of the enzyme.

2. Co-enzymes:
They are also organic compounds loosely bound to apoenzyme for catalysis. Co-enzymes serve as co-factors in a number of different enzyme-catalyzed reactions. Many coenzymes are vitamins eg: coenzyme nicotinamide adenine dinucleotide (NAD) and NADP contain the vitamin niacin.

2. Metations:
Zinc is a cofactor for the proteolytic enzyme carboxypeptidase. Catalytic activity is lost when the co-factor is removed from the enzyme.

Students can Download Chapter 11 Chemical Coordination and Integration Notes, Plus One Zoology Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Zoology Notes Chapter 11 Chemical Coordination and Integration

What is neural system?
The neural system and the endocrine system coordinate and regulate the physiological functions in the body.

Endocrine Glands And Hormones:
Endocrine glands lack ducts and are called ductless glands. Their secretions are called hormones.

Human Endocrine System
The endocrine glands are located in different parts of our body constitute the endocrine system. Pituitary, pineal, thyroid, adrenal, pancreas, parathyroid, thymus and gonads (testis in males and ovary in females) are the organised endocrine bodies in our body.

In addition to these, some other organs, eg: gastrointestinal tract, liver, kidney, heart also produce hormones.

The Hypothalamus:
The hypothalamus is the basal part of diencephalon, forebrain and it regulates body functions. The hormones produced by hypothalamus are of two types

1. The releasing hormones (which stimulate secretion of pituitary hormones)
2. The inhibiting hormones (which inhibit secretions of pituitary hormones).

For example,

These hormones originating in the hypothlamic neurons, pass through axons and are released from their nerve endings reach the pituitary gland through a portal circulatory system and regulate the functions of the anterior pituitary. The posterior pituitary is under the direct neural regulation of the hypothalamus.

The Pituitary Gland:
The pituitary gland is located in a bony cavity called sella tursica. It is divided into an adenohypophysis and a neurohypophysis.

Adenohypophysis:
It consists of two portions, pars distalis and pars intermedia. The pars distalis region of pituitary, commonly called anterior pituitary, produces growth hormone (GH), prolactin (PRL), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), luteinizing hormone (LH) and follicle stimulating hormone (FSH).

Pars intermedia secretes only one hormone called melanocyte stimulating hormone (MSH). Pars intermedia is almost merged with pars distalis.

Neurohvpophysis:
It is also known as posterior pituitary, stores and releases two hormones called

1. Oxytocin
2. vasopressin

Function:
These are synthesised by the hypothalamus and are transported to neurohypophysis.

Growth hormone:
Over-secretion of GH stimulates abnormal growth of the body leading to gigantism and low secretion of GH results in stunted growth resulting in pituitary dwarfism. Prolactin regulates the growth of the mammary glands and formation of milk in them.

TSH stimulates the synthesis arid secretion of thyroid hormones from the thyroid gland. ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids from the adrenal cortex. LH and FSH stimulate gonadal activity and called as gonadotrophins.

Activity of LH and FSH in males and females:
In males, LH stimulates the synthesis and secretion of hormones called androgens from testis. In males, FSH and androgens regulate spermatogenesis. In females, LH induces ovulation of fully mature follicles (graafian follicles) and maintains the corpus luteum, formed from the graafian follicles after ovulation.

In females FSH stimulates growth and development of the ovarian follicles. MSH acts on the melanocytes (melanin containing cells) and regulates pigmentation of the skin. Oxytocin stimulates a vigorous contraction of uterus at the time of child birth, and milk ejection from the mammary gland.

Hormone in water reabsorption:
Vasopressin acts on kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduces loss of water through urine (diuresis). Hence, it is also called as anti-diuretic hormone (ADH).

The Pineal Gland:
The pineal gland is located on the dorsal side of forebrain. It secretes a hormone called melatonin. It regulates 24-hour (diurnal) rhythm of our body. For example, it helps in maintaining sleep-wake cycle, body temperature, metabolism, pigmentation, the menstrual cycle as well as our defense capability.

Thyroid Gland:
It is composed of two lobes which are located on either side of the trachea. The thyroid gland is composed of follicles and stromal tissues. The follicular cells synthesise two hormones, tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3). Deficiency of iodine in our diet results in hypothyroidism and enlargement of the thyroid gland called goitre.

Hypothyroidism during pregnancy causes defective development and maturation of the growing baby leading to stunted growth (cretinism), mental retardation, low intelligence quotient, abnormal skin, deaf-mutism, etc.

In adult women, hypothyroidism cause the occurrence of irregular menstrual cycle. Due to cancer of the thyroid gland the synthesis and secretion of the thyroid hormones is increased to abnormal high levels leading to a condition called hyperthyroidism.

Parathyroid Gland:
It is present on the back side of the thyroid gland and secrete a peptide hormone called parathyroid hormone (PTH).

PTH also stimulates reabsorption of Ca²⁺ by the renal tubules and increases Ca²⁺ absorption from the digested food. Hence PTH is a hypercalcemic hormone i.e., it increases the blood Ca²⁺ levels. Along with TCT, it plays a significant role in calcium balance in the body.

Thymus:
The thymus gland is located on the dorsal side of the heart and the aorta and plays a major role in the development of the immune system.

Adrenal Gland:
It is located at the anterior part of each kidney. The gland is composed of inner adrenal medulla, and outside the adrenal cortex.

Adrenal medulla:

Adrenaline and noradrenaline are secreted during emergency situations and are called emergency hormones or hormones of Fight or Flight. These hormones increase alertness, pupilary dilation, piloerection (raising of hairs), sweating, etc.

These hormones increase the heart beat, the strength of heart contraction and the rate of respiration. Catecholamines stimulate the breakdown of glycogen resulting in an increased concentration of glucose in blood. They also stimulate the breakdown of lipids and proteins.

Adrenal cortex:
It is divided into three layers, called

1. zona reticularis (inner layer)
2. zonafasciculata (middle layer)
3. zona glomerulosa (outer layer).

The secretory hormones are commonly called as corticoids. They are involved in carbohydrate metabolism called as glucocorticoids. eg: Cortisol.

Function:
It maintains the cardio-vascular system as well as the kidney functions, suppresses the immune response and stimulates the RBC production. Corticoids, which regulate the balance of water and electrolytes in our body are called mineralocorticoids. eg: Aldosterone.

Glucocorticoids stimulate, gluconeogenesis, lipolysis and proteolysis and inhibit cellular uptake and utilisation of amino acids. Aldosterone stimulates the reabsorption of Na⁺ and water and excretion of K⁺ and phosphate ions.

Hence it helps in the maintenance of electrolytes, body fluid volume, osmotic pressure and blood pressure. Androgenic steroids secreted by the adrenal cortex which play a role in the growth of axial hair, pubic hair and facial hair during puberty.

Pancreas:
It acts as both exocrine and endocrine gland. The endocrine consists of ‘Islets of Langerhans’.

Glucagon is a peptide hormone maintains the normal blood glucose levels, stimulates glycogenolysis – increased blood sugar (hyperglycemia),stimulates the process of gluconeogenesis – contributes to hyperglycemia. Insulin is a peptide hormone, which enhances cellular glucose uptake and utilisation.

As a result, there is a rapid movement of glucose from blood to hepatocytes and adipocytes resulting in decreased blood glucose levels (hypoglycemia). Insulin also stimulates conversion of glucose to glycogen (glycogenesis) in the target cells.

Prolonged hyperglycemia leads to a complex disorder called diabetes mellitus which is associated with loss of glucose through urine and formation of harmful compounds known as ketone bodies.

Testis:
A pair of testis is present in the scrotal sac of male individuals Testis performs dual functions as a primary sex organ as well as an endocrine gland. Testis is composed of seminiferous tubules and stromal or interstitial tissue. The Leydig cells or interstitial cells, which produce a group of hormones called androgens mainly testosterone.

Androgens regulate the development, maturation and functions of the male accessory sex organs like epididymis, vas deferens, seminal vesicles, prostate gland, urethra etc.

Androgens also stimulate muscular growth, growth of facial and axillary hair, aggressiveness, low pitch of voice, spermatogenesis (formation of spermatozoa), influence the male sexual behaviour (libido).

These hormones produce anabolic (synthetic) effects on protein and carbohydrate metabolism.

Ovary:
It is the primary female sex organ which produces one ovum during each menstrual cycle. Ovary produces two groups of steroid hormones called estrogen and progesterone. The estrogen is are secreted by the growing ovarian follicles. After ovulation, the ruptured follicle is converted to a structure called corpus luteum, which secretes progesterone.

Estrogens involved in stimulation of growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters (e.g., high pitch of voice, etc.), mammary gland development, regulate female sexual behaviour.

Progesterone supports pregnancy, stimulates the formation of alveoli (sac-like structures which store milk) and milk secretion.

Hormones Of Heart Kidney And Gastrointestinal Tract:
The atrial wall of our heart secretes a very important peptide hormone called atrial natriuretic factor (ANF), which decreases blood pressure. When blood pressure is increased, ANF is secreted which causes dilation of the blood vessels. This reduces the blood pressure.

The juxtaglomerular cells of kidney produce a peptide hormone called erythropoietin which stimulates erythropoiesis (formation of RBC). The gastro-intestinal tract secrete four major peptide hormones, namely gastrin, secretin, cholecystokinin (CCK) and gastric inhibitory peptide (GIP).

Gastrin stimulates the secretion of hydrochloric acid and pepsinogen. Secretin stimulates secretion of water and bicarbonate ions. CCK acts on both pancreas and gall bladder and stimulates the secretion of pancreatic enzymes and bile juice, respectively. GIP inhibits gastric secretion and motility.

Mechanism Of Hormone Action:
Hormones bind to specific proteins called hormone receptors Hormone receptors present on the cell membrane of the target cells are called membrane-bound receptors and the receptors present inside the target cell are called intracellular receptors.

Binding of a hormone to its receptor leads to the formation of a hormone-receptor complex. Hormone- Receptor complex formation leads to certain biochemical changes in the target tissue. On the basis of their chemical nature, hormones can be divided into groups.

1. peptide,
2. polypeptide,
3. protein hormones (eg: insulin, glucagon, pituitary hormones, hypothalamic hormones, etc.)
   • steroids (eg: cortisol, testosterone, estradiol and progesterone)
   • iodothyronines (thyroid hormones)
   • amino-acid derivatives (eg: epinephrine).

Hormones which interact with membrane-bound receptors do not enter the target cell, but generate second messengers (eg: cyclic AMP, IP3, Ca^++, etc) which in turn regulate cellular metabolism. Hormones which interact with intracellular receptors (eg: steroid hormones, iodothyronines, etc.) regulate gene expression or chromosome function.

Exophthalmic goitre, also called Grave’s disease:
This occurs due to hyperthyroidism i.e the excessive secretion of thyroxine hormone is accompanied by the enlargement of the thyroid glands. It is an autoimmune disease where patients produce antibodies that act on the thyroid glands to increase thyroxine hormone production and thyroid size. eg: Patients suffering from cancerof thyroid glands.

The symptoms are elevated metabolic rate, sweating, rapid and irregular heartbeat, weight loss despite increased appetite, frequent bowel movement and nervousness. Some patients may also experience exophthalmos (or protrusion of the eyeballs). Thus this condition is also known as exophthalmic goitre.

Addison’s’ disease:
The hyposecretory disorder of the adrenal cortex or destruction of adrenal cortex in diseases such as tuberculosis leads to deficit of both glucocorticoids and mineralocorticoids. This condition is known as Addison’s disease. The symptoms are loose weight, their blood glucose and sodium levels drop and potassium levels rise.

NCERT SUPPLEMENTARY SYLLABUS
Exophthalmic goitre, also called Grave’s disease:
This occurs due to hyperthyroidism i.e the excessive secretion of thyroxine hormone is accompanied by the enlargement of the thyroid glands.

It is an autoimmune disease where patients produce antibodies that act on the thyroid glands to increase thyroxine hormone production and thyroid size. eg: Patients suffering from cancer of thyroid glands.

The symptoms are elevated metabolic rate, sweating, rapid and irregular heartbeat, weight loss despite increased appetite, frequent bowel movement and nervousness. Some patients may also experience exophthalmos (or protrusion of the eye balls). This condition is also known as exophthalmic goitre.

Addison’s’ disease:
The hyposecretory disorder of the adrenal cortex or destruction of adrenal cortex in diseases such as tuberculosis leads to deficit of both glucocorticoids and mineralocorticoids.

This condition is known as Addison’s disease. The symptoms are weight loss, blood glucose and sodium levels drop and potassium levels rise.

Students can Download Chapter 12 Accounting System Using Database Management System Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 12 Accounting System Using Database Management System

Summary:
Accounting Reports:
A report displays information that is acquired from data processing and transformation in an organised manner. Reports tend to reduce the level of uncertainty associated with decision-makers and also influence their positive actions.

The output of the computerised accounting system are accounting reports. Financial accounting reports such as Cash book, Bank book, Ledger and Trial Balance may be generated in Access by adhering to report generation process.

Using Access for Producing Reports:
In Access, the reports are created by designing a report, identifying its information requirement, creating the queries in SQL to generate such information so that the final SQL statement provides the record set of information to the report design. Different Models of database design require different sets of SQL statements to produce different types of reports.

Queries Access:
There are several types of queries in Access that may be used to generate information. Such queries are called select queries because they are used to select records from the given set of records. There are three ways in which these queries may be created in Access: Wizard. Design View and SQL view method.

Designing Reports in Access:
A report in Access may be designed in three ways: Auto Report. Wizard and Design View method. An SQL statement (or query) is capable of displaying records containing fields from across a number of data tables.

A typical report in Access has the structure that consists of Report header, Page header, Group header, Details, Group footer, Page footer and Report footer.

Students can Download Chapter 11 Structuring Database for Accounting Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 11 Structuring Database for Accounting

Summary:
Database Concepts:

1. Reality: It consists of different components of an organisation such as people, facilities and other resources.

2. Data: It represents data concerning people, places, objects entities, events, etc., and non-financial 14 nature.

3. Database: It was a shared collection of inter-related data tables, tiles or structures which are designed to most varied information needs of all organisations.

4. International: Processed data organisation in a form that is suitable for decision-making.

5. DBMS: A collection of programmes that enable users to create and maintain a database.

Database System Concepts and Architecture Data model:
Collection of concepts used to describe the structure of a database.

1. Database Schemes: The description of a database is called its scheme.
2. Database State and Instances: Data in a database at a particular movement is called database state.

Entity-Relationship (ER) Model:
An important concept of data model mostly used in a database-oriented application. The major elements of ER model are entities attributes, identities and relationship that are used to express reality for which a database is to be designed.

Relation Data Model (RDM):
It represents the database at collection of tables comprising different volumes. It consists of rows and columns. The table name and column name are used to help in interpreting the meaning of volumes of each row. Each row of table is called a data record.

Students can Download Chapter 10 Applications of Computers in Accounting Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 10 Applications of Computers in Accounting

Summary:
Meaning of a Computer:
The computer is an electronic device capable of performing a variety of operations as desired by a set of instructions.

Elements of a Computer System:

1. Hardware
2. People
3. Data Connectivity
4. Software
5. Procedure

Capabilities of a Computer:

1. Speed
2. Reliability
3. Storage
4. Accuracy
5. Versatility

Need for Computers in Accounting:
The advent of globalisation has resulted in a rise in business operations. Consequently, every medium and large-sized organisations require well-established information system in order to generate information required for decision making and achieving the organisational objectives. This made Information technology to play a vital role in supporting business operations.

MIS and Accounting Information System:
A management information system provides information necessary to take decisions and manage an organisation effectively. Accounting information system on the other hand identifies, collects, processes and communicates economic information about an entity to a wide variety of users.

Accounting Reports:
Information supplied to meet a particular need is called a report. An accounting report must fulfil the following conditions:

• Relevance
• Timeliness
• Accuracy
• Completeness
• Summarisation

Computerised Accounting System:
A computerised accounting system is an accounting information system that processes the financial transactions and events to produce reports as per user requirements. It is based on the concept of database and has two basic requirements:

1. Accounting framework and
2. Operating Procedure.

Advantages of Computerised Accounting System:

1. Speed
2. Reliability
3. Scalability
4. Efficiency
5. MIS Reports
6. Storage and Retrieval
7. Accuracy
8. Up-to-date
9. Legibility
10. Quality Report
11. Real-time user interface
12. Motivation and Employees interest
13. Automated document production

Limitations of Computerised Accounting System:

• Cost of training
• Disruption
• Breach of security
• Inability to check unanticipated errors
• Staff Opposition
• System failure
• III-effects on health

Categories of Accounting Packages:

• Ready-to-Use
• Tailored
• Customised

Students can Download Chapter 9 Accounts from Incomplete Records Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 9 Accounts from Incomplete Records

Summary:
Incomplete Records:
Incomplete records refer to a lack of accounting records according to the double-entry system. It is an incomplete, unscientific and unsystematic method of keeping the books of accounts of a trader.

Computation of profit and loss from incomplete records:
The statement of affairs is used to compute capital when a firm has a set of incomplete records. It shows assets on one side and the liabilities on the other as in the case of a balance sheet. The difference between the totals of the two sides is the capital.

Format of Statement of Affairs:
Statement of Affairs as on …………………

The statement of profit or loss is prepared to ascertain the exact amount of profit or loss made during the year.

Format of Statement of Affairs:
Statement of Profit or Loss for the year ended ………….

Preparation of Profit and Loss Account and Balance Sheet. (Conversion method):
In order to prepare final accounts from incomplete records, we have to find out the missing figures by making further computations and adjustments to the available information. The following are the steps to prepare the final accounts from incomplete records.

(i) Preparation of statement of Affairs.
(ii) Preparation of cash book
(iii) Ascertaining credit purchases and credit sales:-
Credit purchase can be ascertained by preparing a statement or by preparing Total creditors Account.

Format of Total Creditors Account:

Format of Total Creditors Account:

(a) Bills Receivable and Bills payable Accounts are prepared for finding out their opening or closing balances or for finding out the amount of bills accepted or bills received during the year.

(b) The proforma of total bills receivable account and total bills payable account. The proforma of total bills receivable account and total bills payable account is shown.

Total Bills Receivable Account:

Total Bills Payable Account:

(iv) Calculate:

• Total purchase by adding cash purchases and credit purchases.
• Total sales by adding cash sales and credit sales.

(v) Prepare Trial balance with the given information and missing information ascertained:
The components of the trial balance and their sources of information are summarised below

(vi) Prepare final accounts in the usual manner.

Students can Download Chapter 8 Financial Statements – I & II Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 8 Financial Statements – I & II

Summary:
Financial Statements:
Meaning and types Financial statements are the statements which present periodic reports on the process of business enterprises and the results achieved during a given period. Financial statement includes trading, profit & loss account, balance sheet and other statements.

Trading and Profit & Loss Account:
Trading and Profit & Loss account is prepared to ascertain the net result of business operations during a given period.

Format of Trading and Profit & Loss Account (In horizontal form):
Trading and Profit & Loss Account for the year ended ………………

Need for Adjustment:
For the preparation of financial statements, it is necessary that all adjustments arising out of the accural basis of accounting are made at the end of the accounting period. Entries which are given outside the trial balance are called adjustment entries.

Treatment of various types of adjustments:

Balance Sheet:
The balance sheet is a statement of assets and liabilities of a business enterprises and shows the financial position at a given date. It is not an account. It is only a statement.
Assets and liabilities shown in the balance sheet are marshalled in order to liquidity or in order to permanence.

Format of Balance Sheet (In horizontal form)
Balance sheet as on …………….

The Performa of income statement and balance sheet in vertical form.

Income Statement for the period ended ……..

Balance sheet as on………..

Students can Download Chapter 10 Neural Control and Coordination Notes, Plus One Zoology Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Zoology Notes Chapter 10 Neural Control and Coordination

What is coordination?
Coordination is the process through which two or more organs interact and complement the functions of one another.

Neural System
The neural system of all animals is composed neurons that receive and transmit different kinds of stimuli.

Neural system in lower forms

• The neural organisation is very simple in lower invertebrates.
• For example, in Hydra it is composed of a network of neurons.
• The neural system is better organised in insects, where a brain is present.

The vertebrates have a more developed neural system.

Human Neural System
The human neural system is divided into two parts:

• The CNS includes the brain and the spinal cord and is the site of information processing and control.
• The PNS comprises of all the nerves of the body associated with the CNS.

The nerve fibres of the PNS are of two types:

Function of afferent efferent of nerve fibres:
The afferent nerve fibres transmit impulses from tissues/organs to the CNS. The efferent fibres transmit regulatory impulses from the CNS to the peripheral tissues/organs.
The PNS is divided into two divisions

1. Somatic neural system
2. Autonomic neural system.

Function:
The somatic neural system relays impulses from the CNS to skeletal muscles. The autonomic neural system transmits impulses from the CNS to the involuntary organs and smooth muscles of the body.
The autonomic neural system is classified into

1. sympathetic neural system
2. parasympathetic neural system.

Neuron As Structural And Functional Unit Of Neural System
A neuron is composed of three major parts,

1. The cell body contains cytoplasm with cell organelles and certain granular bodies called Nissl’s granules.

2. Repeated branches project out of the cell body are called dendrites.

3. The axon is a long fibre, the distal end of which is branched. Each branch terminates as a bulb-like structure called synaptic knob which possess synaptic vesicles containing chemicals called neurotransmitters. Based on the number of axon and dendrites, the neurons are divided into three types,

• multipolar (with one axon and two or more dendrites; found in the cerebral cortex)
• bipolar (with one axon and one dendrite, found in the retina of eye)
• unipolar (cell body with one axon only found usually in the embryonic stage).

4. The myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon.

5. The gaps between two adjacent myelin sheaths are called nodes of Ranvier.

6. Myelinated nerve fibres are found in spinal and cranial nerves.

8. Non-myelinated nerve fibre is enclosed by a Schwann cell that does not form a myelin sheath around the axon, and is commonly found in autonomous and the somatic neural systems.

Generation and Conduction of Nerve Impulse
Neurons are excitable cells because their membranes are in a polarized state.
In resting state of neuron:
The axonal membrane is more permeable to potassium ions (K⁺) and impermeable to sodium ions (Na⁺) and negatively charged proteins present in the axoplasm. The fluid outside the axon contains a low concentration of K⁺, a high concentration of Na⁺ and thus form a concentration gradient.

These ionic gradients are maintained by the active transport of ions by the sodium-potassium pump which transports 3 Na⁺ outwards for 2 K⁺ into the cell.

As a result, the outer surface of the axonal membrane possesses a positive charge while its inner surface becomes negatively charged and therefore is polarised. The electrical potential difference across the resting plasma membrane is called as the resting potential.

When a stimulus is applied at a site on the polarised membrane:
The membrane freely permeable to Na and influx of Na⁺ followed by the reversal of the polarity at that site, i.e., the outer surface of the membrane becomes negatively charged and the inner side becomes positively charged.

This is called depolarized state. The electrical potential difference across the plasma membrane is called the action potential At sites immediately ahead, the axon membrane has a positive charge on the outer surface and a negative charge on its inner surface. As a result, a current flows on the inner surface from site A to site B.

On the outer surface current flows from site B to site A to complete the circuit of current flow. Hence, the polarity at the site is reversed, and an action potential is generated at site B. Thus, the impulse (action potential) generated at site A arrives at site B. The sequence is repeated along the length of the axon and consequently the impulse is conducted.

Transmission of Impulses
A nerve impulse is transmitted from one neuron to another through junctions called synapses. The junction between pre-synaptic neuron and a post-synaptic neuron is called synaptic cleft. There are two types of synapses, namely

At electrical synapses, erlectrical current flowdirectly from one neuron into the other across these synapses. It is very similar to impulse conduction along a single axon, impulse transmission across an electrical synapse is always faster than that across a chemical synapse.

At a chemical synapse, the membranes ofthepre-and post-synaptic neurons are separated by a fluid-filled space called synaptic cleft Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses.

The released neurotransmitters bind to the specific receptors, present on the post-synaptic membrane. This binding opens ion channels allowing the entry of ions which can generate a new potential in the post- synaptic neuron.

Central Neural System
It controls the voluntary movements such as balance of the body, functioning of vital involuntary organs (e.g., lungs, heart, kidneys, etc.), thermoregulation, hunger and thirst, circadian (24-hour) rhythms of our body, activities of several endocrine glands and human behaviour.

It is also the site for processing of vision, hearing, speech, memory, intelligence, emotions and thoughts. The human brain is well protected by the skull. Inside the skull, the brain is covered by cranial meninges consisting of an outer layer called dura mater, a very thin middle layer called arachnoid and an inner layer called pia mater.

The brain is divided into three major parts:

• forebrain
• midbrain
• hindbrain

Forebrain
The forebrain consists of cerebrum, thalamus and hypothalamus. Cerebrum forms the major part of the human brain. Cerebrum divided longitudinally into two halves the left and right cerebral hemispheres. The hemispheres are connected by nerve fibres called corpus callosum.

The layer of cells which covers the cerebral hemisphere is called cerebral cortex. The cerebral cortex is referred to as the grey matter .The cerebral cortex contains motor areas, sensory areas and large regions These regions called as the association areas.They are responsible functions like memory and communication.

The inner part of cerebral hemisphere gives white appearance to the layer and called as the white matter. Hypothalamus lies at the base of the thalamus contains a number of centres which control body temperature, urge for eating and drinking. Hypothalamus secrete hormones called hypothalamic hormones.

he inner parts of cerebral hemispheres and a group of associated deep structures like amygdala, hippocampus, etc., form a complex structure called the limbic lobe or limbic system. Along with the hypothalamus,

Midbrain
The midbrain is located between the thalamus/hypothalamus of the forebrain and pons of the hindbrain. A canal called the cerebral aqueduct passess through the midbrain.

The dorsal portion of the midbrain consists mainly of four round swellings (lobes) called corpora quadrigemina. Midbrain and hindbrain form the brain stem..

Hindbrain
The hindbrain comprises pons, cerebellum and medulla (also called the medulla oblongata). Pons consists of fibre tracts that interconnect different regions of the brain. Cerebellum provide the additional space for many more neurons.

The medulla of the brain is connected to the spinal cord. The medulla contains centres which control respiration, cardiovascular reflexes and gastric secretions.

Reflex Action And Reflex Arc
It involves the sudden withdrawal of a body part which comes in contact with objects that are extremely hot, cold pointed or animals that are poisonous. The reflex pathway consists of one afferent neuron (receptor) and one efferent (effector or excitor) neuron arranged in a series.

The afferent neuron receives signal from a sensory organ and transmits the impulse via a dorsal nerve root into the CNS (at the level of spinal cord). The efferent nueuron carries signals from CNS to the effector. The stimulus and response thus forms a reflex arc in the knee jerk reflex.

Sensory Reception And Processing
The sensory organs detect all types of changes in the environment and sent to different parts/centres of the brain. The sense organs are the eye (sensory organ for vision) and the ear (sensory organ for hearing).

Eye
Our paired eyes are located in sockets of the skull called orbits.

Parts of an eye
The wall of the eye ball is composed of three layers. External layer is composed of a dense connective tissue and is called the sclera. Anterior portion of this layer is called the cornea. Middle layer, choroid, contains many blood vessels and looks bluish in colour.

The choroid layer is thin over the posterior part of eye ball, but it becomes thick in the anterior part to form the ciliary body. The ciliary continues forward to form a pigmented and opaque structure called the iris which is the visible coloured portion ofthe eye.

1. The eye ball contains lens which is held in place by ligaments attached to the ciliary body. In front of the lens, the aperture surrounded by the iris is called the pupil.
2. The inner layer is the retina contains three layers of cells – from inside to outside.
3. Ganglion cells, bipolar cells and photoreceptor cells.
4. There are two typ es of photoreceptor cells, namely, rods and cones
5. The daylight (photopic) vision and colour vision are functions of cones
6. The twilight (scotopic) vision is the function of the rods.
7. The rods contain a purplish-red protein called the rhodopsin which contains a derivative of Vitamin A. In the human eye, there are three types of cones that respond to red, green and blue lights.

What is blind spot?
The optic nerves and the retinal blood vessels enter above the posterior pole of the eye ball. Photoreceptor cells are not present in that region and hence it is called the blind spot.

What is macula lutea?
At the posterior pole of the eye lateral to the blind spot, there is a yellowish pigmented spot called macula lutea with a central pit called the fovea where only the cones are densely packed. It is the point where the visual acuity (resolution) is the greatest.

The space between the cornea and the lens is called the aqueous chamber and contains fluid called aqueous humor. The space between the lens and the retina is called the vitreous chamber and contains fluid called vitreous humor.

Mechanism of Vision
The light rays falls on the retina through cornea and lens generate impulses in rods and cones. The photosensitive compounds (photopigments) in the human eyes is composed of opsin (a protein) and retinal (an aldehyde of vitamin A). Light induces the changes in the structure of the opsin.

This causes membrane permeability changes. As a result, potential differences are generated in the photoreceptor cells. This produces a signal that generates action potentials in the ganglion cells through the bipolar cells.

These action potentials are transmitted by the optic nerves to the visual cortex area of the brain, where the neural impulses are analysed and the image formed on the retina is recognised based on earlier memory and experience.

The Ear
The ear is divided into three major sections called the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and external auditory meatus (canal).The pinna collects the vibrations of sound. The external auditory meatus leads inwards and extends up to the tympanic membrane (the ear drum).

There are wax-secreting sebaceous glands in the skin of the pinna and the meatus. The middle ear contains three ossicles called malleus, incus and stapes which are attached to one another in a chain-like fashion.

The malleus is attached to the tympanic membrane and the stapes is attached to the oval window. of the cochlea. The ear ossicles increase the efficiency of transmission of sound waves to the inner ear.

An Eustachian tube connects the middle ear cavity with the pharynx. The Eustachian tube helps in equalising the pressures on either sides of the eardrum. The fluid-filled inner ear called labyrinth consists of two parts, the bony and the membranous labyrinths.

The bony labyrinth is connected with membranous labyrinth, which is surrounded by a fluid called perilymph. The membranous labyrinth is filled with a fluid called endolymph. The coiled portion of the labyrinth is called cochlea.

The membranes constituting cochlea, the reissner’s and basilar, divide the surounding perilymph filled bony labyrinth into an upper scala vestibuli and a lower scala tympani. The space within cochlea called scala media is filled with endolymph.

At the base of the cochlea, the scala vestibuli ends at the oval window The organ of corti is a structure located on the basilar membrane which contains hair cells that act as auditory receptors. The hair cells are present in rows on the internal side of the organ of corti.

The basal end of the hair cell is in close contact with the afferent nerve fibres. A large number of processes called stereo cilia are projected from the apical part of each hair cell. Above the rows of the hair cells is a thin elastic membrane called tectorial membrane. The inner ear also contains vestibular apparatus, located above the cochlea.

The vestibular apparatus is composed of three semi-circular canals and the otolith organ consisting of the saccule and utricle. The membranous canals are suspended in the perilymph of the bony canals. The base of canals is swollen and is called ampulla, which contains a projecting ridge called crista ampullaris which has hair cells.

The saccule and utricle contain a projecting ridge called macula. The crista and macula are the specific receptors of the vestibular apparatus responsible for maintenance of balance of the body and posture.

Mechanism of Hearing
How does ear convert sound waves into neural impulses, which are sensed and processed by the brain enabling us to recognise a sound?
The external ear receives sound waves and directs them to the ear drum.The ear drum vibrates in response to the sound waves and these vibrations are transmitted through the ear ossicles (malleus, incus and stapes) to the oval window.

The vibrations are passed through the oval window on to the fluid of the cochlea, where they generate waves in the lymphs. The waves in the lymphs induce a ripple in the basilar membrane. These movements of the basilar membrane bend the hair ceils, pressing them against the tectorial membrane.

As a result, nerve impulses are generated in the associated afferent neurons. These impulses are transmitted by the afferent fibres via auditory nerves to the auditory cortex of the brain, where the impulses are analysed and the sound is recognized.

The vibrations are passed through the oval window on to the fluid of the cochlea, where they generate waves in the lymphs. The waves in the lymphs induce a ripple in the basilar membrane. These movements of the basilar membrane bend the hair cells, pressing them against the tectorial membrane.

As a result, nerve impulses are generated in the associated afferent neurons. These impulses are transmitted by the afferent fibres via auditory nerves to the auditory cortex of the brain, where the impulses are analysed and the sound is recognized.

NCERT SUPPLEMENTARY SYLLABUS
Sense organs:
The environmental changes (both internal and external) called stimuli detected by the special sensory cells, are conveyed to the brain in the form of nerve impulses. The response for each stimulus from brain is sent to the various body parts for its well being. There are five senses: touch, vision, hearing, smell and taste.

While touch is a complex general sense, the other four are special senses. The general sensory receptors are simple receptors that are present in the skin, mucous membranes, connective tissues and muscles.

These sense the information such as tactile sensation (a mix of touch, pressure, stretch and vibration), heat, cold, pain and muscle sense.

Special sensory receptors are present in the head especially sensory organs like eyes and ears and tissues of the taste buds and olfactory epithelium. These sensory organs and tissues of eye and ear are photoreceptors and the auditory receptors respectively.

The chemical senses: the taste and smell:
The receptors fortaste and smell are called as chemoreceptors found as film of liquid coating in the membranes of the receptor cells. The taste receptors are specialized cells that detect chemicals present in the mouth while smell receptors are modified sensory neurons in the nasal passage which detect the volatile chemicals.

These two types of receptors complement each other and often respond to the same stimulus. The smell receptors are 3,400 times more sensitive than the taste receptors.

Sense of smell (olfaction):
Nose contains the receptors of smell, in the mucous coated thin, yellowish patch (about 5 cm2) of modified pseudo stratified epithelium called olfactory epithelium. It is located at the roof of the nasal cavity on either sides of the nasal septum.

The olfactory epithelium contains three types of cells:

• millions of olfactory receptor cells
• columnar supportive cells
• short basal cells.

Olfactory receptors bear a cluster of about 20 modified cilia which function as receptor sites. These cilia extend from the olfactory epithelium into the thin coat of nasal mucous secreted by the supportive cells and olfactory glands. This mucous dissolves the airborne odour molecules.

Once dissolved, the chemicals bind to the specific receptors on the cilia stimulating the receptor cells. This causes depolarization then action potential in the receptor cell.

The axons of the olfactory receptors unite to form the olfactory nerve which transmits the information directly to olfactory bulb, a relay station in the brain. The nasal cavity contains pain receptors that respond to irritants such as ammonia, vinegar or hot chilly pepper.

Impulses from these pain receptors reach the brain. The brain combines these sensations with those of smell to identify the odours Humans can detect about 10,000 different odours but the olfactory capability of fish and mammals such as a dog is high.

Sense of taste (gustation):
The receptor cells fortaste are located in taste buds. Humans have about 10,000 taste buds are located in pockets around the papillae on the surface and sides of the tongue, but some on the surface of the pharynx and the larynx.

Each taste bud contains about 40 specialized receptor cells or gustatory cells, that helps to replace the worn out cells of the taste buds. The receptor cells for taste are not neurons, but they are microvilli .The microvilli protrude into the surrounding fluids through a narrow opening called the taste pore.

Dissolved chemicals contacting the microvilli bind to specific receptor proteins on the microvilli, thereby depolarizing the cell,it releases neurotransmitter which leads to the generation of an action potential in the associated sensory neuron.

Each dendrite receives signals from several receptor cells within the taste bud pass to the brain stem. From here the nerve impulse is relayed to the taste centre in the cerebral cortex of the brain that perceives the taste sensation.
In humans there are four basic taste senses:

Sense of touch:
Skin is the largest sense organ. These sensations of touch come from millions of microscopic simple sensory receptors located all over the skin and associated with the general sensations of contact or pressure, heat, cold, and pain. Some parts of the body have a large number of these such as the fingertips.

Structurally, these touch receptors are either free dendritic endings or encapsulated dendritic endings present in the skin (and other parts of the body). Free or bare dendritic nerve endings are present throughout the epidermis in “zigzag” form .These respond chiefly to pain and temperature but some respond to pressure as well.

Whenever one or more of these sensory receptors are stimulated (by heat, cold, vibrations, pressure or pain) an impulse or action potential is generated. This impulse is then taken to the spinal cord and from there to the brain which analyses the stimulus and then generates appropriate response.

Students can Download Chapter 7 Bill of Exchange Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 7 Bill of Exchange

Summary:
Bill of Exchange:
A bill of exchange is an acknowledgement of debt given by one person to another, incorporating all the terms and conditions of payment.

Features and advantages of a bill:
A bill is a written unconditional order, it is signed by the creditor and accepted by the debtor, the amount of the bill is payable either on demand or at a fixed period.

Parties to a bill of Exchange:
There are three parties, ie., drawer, drawee and payee.

Promissory Note:
A promissory note is an undertaking in writting given by the debtor to the creditor to pay the latter a certain sum of money in accordance with the conditions stated therein. There are two parties to a promissory note, the promissor and the promisee.

Maturity of Bill:
The term maturity refers to the date on which a bill or promissory note becomes due for payment. In arriving at the maturity date three days known as “days of grace” must be added to the date on which the period of credit expires instrument is payable.

Endorsement:
An endorsement is a written order on the back of the instrument by the payee or the holder for transferring his right to another person.

Accounting treatment:
A bill can be treated in the following four ways by its receiver.

Dishonour of a bill:
A bill is said to have been dishonoured when the drawee fails to make the payment on the date of maturity. In this situation, liability of the acceptor is restored. Therefore, the entries made on the receipt of the bill should be reserved. The entries of dishonour of bill as follows
(i) When the bill was kept by drawer till maturity.

Noting Charges:
When a bill is dishonoured due to non-payment, it is usual to get it ‘noted’, to establish the matter of dishonour. The noting is done by “Notary Public.” Noting authenticates the fact of dishonour. For providing this service, a fees is charged by the Notary Public which is called Noting Charges. The following facts are generally noted by the Notary;

• Date, fact and reasons of dishonour;
• If the bill is not expressly dishonoured, the reasons why he treats it as dishonoured and;
• The amount of noting charges.

The entries recorded for noting charges in the drawers book are as follows:
When Drawer himself pays:

Where endorsee pays:

When the bank pays on discounted bill:

When the bank pays in the event of sending the bill for collection to the bank:

The entry recorded for noting charges in the book of drawee as follows:
For recording noting charges the drawee opens “Noting ChargesAccount”.

Renewal of the bill:
Sometimes the acceptor of the bill foresees that it may be difficult to meet the obligation of the bill on maturity and may, therefore approach the drawer with the request for extension of time for payment.

If it is so, the old bill is cancelled and . the fresh bill with new terms of payment is drawn and duly accepted and delivered. This is called renewal of the bill. The drawee may have to pay interest to the drawer for the extended period of credit.
Following journal entries are recorded in the case of renewal of the bill.

Retiring of the Bill:
Making payment of the bill of exchange before the due date is called retiring of the bill. To encourage the retirement of the bill, the holder allows some discount called “Rebate on bill” for the period between date of retirement and maturity. The rebate is calculated at a certain rate of interest.

The following journal entries are recorded:
(i) In the book of drawer:
On retiring the acceptance, rebate allowed.

(ii) In the book of drawee:

Students can Download Chapter 9 Locomotion and Movement Notes, Plus One Zoology Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Zoology Notes Chapter 9 Locomotion and Movement

What is locomotion?
The movements result in a change of place or location. Such voluntary movements are called locomotion. Walking, running, climbing, flying, swimming are all some forms of locomotory movements.

Locomotory Movements In Lower Organisms

1. Paramoecium, cilia helps in the movement of food through cytopharynx and locomotion.
2. Hydra use its tentacles for capturing its prey and also use them for locomotion.

All locomotions are movements but all movements are not locomotions.

Types Of Movement
The three main types of movements of cells of the human body are

• Amoeboid
• Ciliary
• Muscular.

Muscle
About 40-50 perent of the body weight of a human adult is contributed by muscles. Muscles are classified based on their location, three types of muscles are identified.

1. Skeletal
2. Visceral
3. Cardiac.

1. Skeletal muscles:
They have a striped appearance and called as striated muscles. They are voluntary muscles because their activities are under the voluntary control of the nervous system. They are involved in locomotory actions and changes of body postures.

2. Visceral muscles:

• They are located in the innerwalls alimentary canal, reproductive tract, etc. They are called smooth muscles (non striated muscle).
• Their activities are not underthe voluntary controlcalled as involuntary muscles.
• They helps in transportation of food through the digestive tract and gametes through the genital tract.

3. Cardiac muscles:

• They are found in the muscles of heart. Based on appearance, cardiac muscles are striated and involuntary.
• Skeletal muscle is made of a number of muscle bundles or fascicles held together by a common collagenous connective tissue layer called fascia
• Each muscle bundle contains a number of muscle fibres. Each muscle fibre is lined by the plasma membrane called sarcolemma enclosing the sarcoplasm.
• Muscle fibre is a syncitium because it contains many nuclei.
• The endoplasmic reticulum, i.e., sarcoplasmic reticulum of the muscle fibres is the store house of calcium ions.

Structure of Contractile Proteins
Each actin filament is made of two ‘F’ (filamentous) actins helically wound to each other. Each ‘F’ actin is a polymer of monomeric ‘G’ (Globular) actins. Two filaments of another protein, tropomyosin also run close to the ‘F’ actins throughout its length.

Acomplex protein Troponin is distributed at regular intervals on the tropomyosin. In the resting state a subunit of troponin masks the active binding sites for myosin on the actin filaments.

Monomeric proteins called Meromyosins forms one thick filament. Each meromyosin has two important parts, a globular head with a short arm and a tail, the former being called the heavy meromyosin (HMM) and the latter, the light meromyosin (LMM). The globular head is an active ATPase enzyme and has binding sites for ATP and active sites for actin.

Mechanism of Muscle Contraction
The sliding filament theory which states that contraction of a muscle fibre takes place by the sliding of the thin filaments over the thick filaments.
Muscle contraction is initiated by a signal sent by the central nervous system (CNS) via a motor neuron. The junction between a motor neuron and the sarcolemma of the muscle fibre is called the neuromuscular junction or motor-end plate.

1. In the junction, the neurotransmitter (Acetyl choline) is released which generates an action potential in the sarcolemma. This spreads and release of calcium ions into the sarcoplasm.
2. Increase in Ca⁺⁺ level leads to the binding of calcium with a subunit of troponin on actin filaments and thereby remove the masking of active sites for myosin.
3. The energy from ATP hydrolysis is used to bind the myosin head with exposed active sites on actin to form a cross bridge.
4. This pulls the attached actin filaments towards the centre of ‘A’ band. The Z’ line attached to these actins are also pulled inwards thereby causing a shortening of the sarcomere, i.e. contraction.
5. During shortening of the muscle the T bands get reduced, whereas the ‘A’ bands retain the length The myosin, releasing the ADP and P1 goes back to its relaxed state.
6. The ATP is again hydrolysed by the myosin head and the cycle of cross bridge formation and breakage is repeated causing further sliding.
7. The process continues till the Ca⁺⁺ ions are pumped back to the sarcoplasmic cisternae resulting in the masking of actin filaments.

This causes the return of ‘Z’ lines back to their original position, i.e., relaxation.

What is muscle fatigue?
Repeated activation of the muscles can lead to the accumulation of lactic acid due to anaerobic breakdown of glycogen causing fatigue. Muscle contains a red coloured oxygen storing pigment called myoglobin. These muscles contain plenty of mitochondria which helps in ATP production.

Hence they are called aerobic muscles. Some of the muscles possess very less quantity of myoglobin and gives whitish appearance . These are the White fibres. Number of mitochondria are also few in them. They depend on anaerobic process for energy.

Seletal System
1. Skeletal system consists of a framework of bones and a few cartilages.

2. Bone and cartilage are specialised connective tissues.

3. The former has a very hard matrix due to calcium salts in it and the latter has slightly pliable matrix due to chondroitin salts. In human beings, this system is made up of 206 bones and a few cartilages. It is grouped into two divisions.

Axial skeleton:

1. It comprises 80 bones distributed along the main axis of the body.
2. The skull, vertebral column, sternum and ribs constitute axial skeleton.

The skull is composed of two sets of bones – Cranial bones are 8 in number. The facial region is made up of 14 skeletal elements which form the front part of the skull.

Diagrammatic view of human skull:
A single U-shaped bone called hyoid is present at the base of the buccal cavity and it is also included in the skull.

What is ear ossicles ?
Each middle ear contains three tiny bones – Malleus, Incus and Stapes, collectively called Ear Ossicles.

Vertebral column:
It is formed by 26 serially arranged units called vertebrae and is dorsally placed. Each vertebra has a central hollow portion (neural canal) through which the spinal cord passes. First vertebra is the atlas and it articulates with the occipital condyles. The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (1-fused)and coccygeal (1-fused) regions starting from the skull.

Vertebral column (right lateral view) Ribs and rib cage. The vertebral column protects the spinal cord, supports the head and serves as the point of attachment for the ribs and musculature of the back.

Sternum:
It is a flat bone on the ventral midline of thorax.
There are 12 pairs of ribs.
1. First seven pairs of ribs are called true ribs. Dorsaily, they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage.

2. The 8^th, 9^th and 10^th pairs of ribs do not articulate directly with the sternum but join the seventh rib with the help of hyaline cartilage. These are called vertebrochondral (false) ribs.

3. Last 2 pairs (11^th and 12^th) of ribs are not connected ventrally and are called floating ribs. Thoracic vertebrae, ribs and sternum together form the rib cage.

Appendicular skeleton:
It includes bones of the limbs alongwith their girdles Each limb is made of 30 bones. The bones of the hand (fore limb) are humerus, radius and ulna, carpals (wrist bones-8 in number), metacarpals (palm bones – 5 in number) and phalanges (digits – 14 in number) Femur (thigh bone – the longest bone), tibia and fibula, tarsals (ankle bones – 7 in number), metatarsals (5 in number) and phalanges (digits -14 in number) are the bones of the legs (hind limb).

A cup shaped bone called patella cover the knee ventrally (knee cap). Pectoral and Pelvic girdle bones help in the articulation of the upper and the lower limbs respectively with the axial skeleton.

Each half of pectoral girdle consists of a clavicle and a scapula. Scapula is a large triangular flat bone situated in the dorsal part of the thorax between the second and the seventh ribs. The dorsal, flat, triangular body of scapula has a slightly elevated ridge called the spine which projects as a flat, expanded process called the acromion.

Below the acromion is a depression called the glenoid cavity which articulates with the head of the humerus to form the shoulder joint. Each clavicle is a long slender bone with two curvatures. This bone is commonly called the collar bone. Pelvic girdle consists of two coxal bones Each coxal bone is formed by the fusion of three bones

1. ilium
2. ischium
3. pubis.

Joints
Joints are points of contact between bones, or between bones and cartilages. The movability of joints vary depending on different factors.
Joints are classified into three,

Disorders Of Muscular And Skeletal System
Myasthenia gravis:
Auto immune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle.

Muscular dystrophy:
Progressive degeneration of skeletal muscle mostly due to genetic disorder.

Tetany:
Rapid spasms (wild contractions) in muscle due to low Ca⁺⁺ in body fluid.

Arthritis:
Inflammation of joints.

Osteoporosis:
Age-related disorder characterised by decreased bone mass and increased chances of fractures. Decreased levels of estrogen is a common cause.

Gout:
Inflammation of joints due to accumulation of uric acid crystals.

NCERT SUPPLEMENTARY SYLLABUS
Types of movements: Flagellar movement
The three main types of movements shown by the cells of the human body are amoeboid, ciliary and muscular. Human sperms shows type of movement called the flagellar movement. The flagellum is the propulsion equipment (due to whip like movement of the tail and the middle piece of the sperm) forthe movement of sperm towards the ovum.

Students can Download Chapter 6 Depreciation, Provisions and Reserves Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 6 Depreciation, Provisions and Reserves

Summary:
Meaning of depreciation:
Depreciation is decline in the value of a tangible fixed asset. In accounting depreciation is the process of allocating depreciable cost over useful life of a fixed asset.

Depreciation and similar terms:
Depreciation term is used in the context of tangible fixed assets. Depletion (in the context of extractive industries), and amortisation (in the context of intangible assets) are other related terms.

Factors Affecting Depreciation:

• Wear and Tear due to use and/or passage of time
• Expiration of Legal Rights
• Obsolescence

Importance of depreciation:

• Depreciation must be charged to ascertain true and fair profit or loss.
• Depreciation is a non-cash operating expense.

Methods of charging depreciation:
Depreciation amount can be calculated using:

• Straight line method, or
• Written down value method

Methods of recording depreciation:
In the books of account there are two types of arrangements for recording depreciation on fixed assets.

• Charging depreciation to asset account or
• Creating provision for depreciation/ accumulated depreciation account.

Charging depreciation to asset account:
According to this arrangement depreciation is deducted from the depreciable cost of the asset (credited to the asset account) and charged (or debited) to profit and loss account. Journal entries under this recording method are as follows:

2. Following two entries are recorded at the end of every year.
(a) For deducting depreciation amount from the cost of the asset.

(b) For charging depreciation to profit and loss account

3. Balance Sheet Treatment
When this method is used, the fixed asset appears at its net book value (ie. cost less depreciation charged till date) on the asset side of the balance sheet and not at its original cost (also known as historical cost).

Creating Provision for depreciation account/ Accumulated depreciation Account:
This method is designed to accumulate the depreciation provided on an asset in a separate account generally called “Provision for Depreciation” or “Accumulated Depreciation” account.

The following journal entries are recorded under this method:

2. The following two journal entries are recorded at the end of each year
(a) For crediting depreciation amount to provision for depreciation account.

(b) For charging depreciation to profit and loss account

3. Balance Sheet treatment
In the balance sheet the fixed asset continues to appear at its original cost on the asset side. The depreciation charged till that date appears in the provision for depreciation account, which is shown either on the “liabilities side” of the balance sheet or by way of deduction from the original cost of the asset concerned on the asset side of the balance sheet.

Disposal of Asset:
Disposal of asset can take place either

• At the end of its useful life or
• During the useful life (due to absolescence or any other abnormal factors). In this case the following journal entries are recorded.

1. For the sale of asset as scrap

2. For transfer of balance in asset account

In case, however “the provision for depreciation account” has been in use for recording the depreciation, then before passing the above entries transfer the balance of the provision for depreciation account to the asset account by recording the following journal entry.

Factors affecting the amount of depreciation:

• Depreciation amount is determined by Original cost
• Salvage value, and
• Useful life of the asset

Provisions and Reserves:
A provision is a charge against profit. It is created for a known current liability the amount of which is uncertain. Reserve on the other hand, is an appropriation of profit. It is created to strengthen the financial position of the business.

Types of Reserves:
Reserves may be:

• General reserve and specific reserve;
• Revenue reserve and capital reserve.

Secret Reserve:
When the total depreciation charged is higher than the total depreciable cost, the Secret reserve is created. The secret reserve is not explicitly shown in the balance sheet.

Students can Download Chapter 5 Trial Balance and Rectification of Errors Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 5 Trial Balance and Rectification of Errors

Summary:
Meaning of trial balance:
A statement showing the abstract of the balance (debit/credit) of various accounts in the ledger.

Objectives of trial balance:
The main objectives of preparing the trial balance are:

• To ascertain the arithmetical accuracy of the ledger accounts;
• To help in locating errors; and
• To help in the preparation of the final accounts.

Preparation of trial balance by the balance method:
In this method, the trial balance has three columns. The first column is for the head of the account, the second column for writing the debit balance and the third for the credit balance of each account in the ledger.

Format of a Trial balance
Trial Balance of ………………… as on March 31.2005

It is normally prepared at the end of an accounting year. However, an organisation may prepare a trial balance at the end of any chosen period, which may be monthly, quarterly, half yearly or annually depending upon its requirements.
In order to prepare a trial balance following steps are taken:

• Ascertain the balances of each account in the ledger.
• List each account and place its balance in the debit or credit column as the case may be. (If an account has a zero balance, it may be included in the trial balance with zero in the column for its normal balance).
• Compute the total of debit balances column.
• Compute the total of the credit balances column.
• Verify that the sum of the debit balances equal the sum of credit balances. If they do not tally, it indicates that there are some errors. So one must check the correctness of the balances of all accounts.

It may be noted that all assets expenses and receivables account shall have debit balances whereas all liabilities, revenues and payables accounts shall have credit balances.

Illustrative Trial Balance

Various types of errors:
1. Errors of commission:
Errors caused due to wrong recording of a transaction, wrong totalling, wrong casting, wrong balancing, etc.

2. Errors of omission:
Errors caused due to omission of recording a transaction entirely or partly in the books of account.

3. Errors of principle:
Errors arising due to wrong classification of receipts and payments between revenue and capital receipts and revenue and capital expenditure.

4. Compensating errors:
Two or more errors committed in such a way that they nullify the effect of each other on the debits and credits.

Rectification of errors:
Errors affecting only one account can be rectified by giving an explanatory note or by passing a journal entry. Errors which affect two or more accounts are rectified by passing a journal entry.

Meaning and utility of suspense account:
An account in which the difference in the trial balance is put till such time that errors are located and rectified. It facilitates the preparation of financial statements even when the trial balance does not tally.

Disposal of suspense account:
When all the errors are located and rectified the suspense account stands disposed off.

Students can Download Chapter 4 Bank Reconciliation Statement Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 4 Bank Reconciliation Statement

Summary
Bank Reconciliation Satement
A statement prepared to reconcile the bank balance as per cash book with the balance as per passbook or bank statement, by showing the items of difference between the two accounts.

Causes of difference
Timing of recording the transaction Errors made by business or by the bank.

Need for Reconciliation
It is generally experienced that when a comparison is made between the bank balance as shown in the firm’s cash book, the two balances do not tally. Hence, we have to first ascertain the causes of difference thereof and then reflect them in a statement called Bank Reconciliation Statement to reconcile (tally) the two balances.

In order to prepare a bank reconciliation statement we need to have a bank balance as per the cash book and a bank statement as on a particular day along with details of both the books.

If the two balances differ, the entries in both the books are compared and the items on account of which the difference has arisen are ascertained with the respective amounts involved so that the bank reconciliation statement may be prepared.

Proforma of bank reconciliation statement

It can also be prepared with two amount columns one showing additions (+ column) and another showing deduction (- column).

Proforma of bank reconciliation statement (table form)

Correct cash balance
It may happens that some of the receipts or payments are missing from either of the books and errors, if any, need to be rectified. This arises the need to look at the entries/errors recorded in both statements and other information available and compute the correct cash balance before reconciling the statements.

Students can Download Chapter 2 Theory Base of Accounting Notes, Plus One Accountancy Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Accountancy Notes Chapter 2 Theory Base of Accounting

Summary:
Generally accepted Accounting Principles (GAAP):
GAAP refers to the rules or guidelines adopted for recording and reporting to business transactions in order to bring uniformity in the preparation and presentation of financial statements. These principles are also referred to as concepts and conventions.

From the practicality viewpoint, the various terms such as principles, conventions, modifying principles, assumptions, etc., have been used interchangeably and are referred to as basic accounting concepts.

Systems of Accounting:
There are two systems of recording business transactions, i.e., double entry system and single entry system.

Basis of Accounting:
There are two broad approach of accounting are cash basis and accural basis. Under cash basis transactions are recorded only when cash are received or paid, where as under accural basis, revenue or costs are recognises when they Occur rather than when they are paid.

Accounting Standards:
Accounting standards are written statement of uniform accounting rules and guidelines in practice for preparing the uniform and consistent financial statements.