Kerala Plus One Botany Model Question Paper 5
Time: 1 Hours
Cool off time : 10 Minutes
General Instructions to candidates :
- There is a ‘cool off time’ of 10 minutes each for Botany and Zoology in addition to the writing time ‘ of 1 hour each. Further there is a ‘ 5 minutes’ ‘preparatory time’ at the end of the Botany Examination and before the commencement of the Zoology Examination.
- Use the ‘cool off time’ to get familiar with the questions and to plan your answers.
- Read the instructions carefully.
- Read questions carefully before you answering.
- Calculations, figures and graphs should be shown in the answer sheet itself.
- Malayalam version of the questions is also provided.
- Give equations wherever necessary.
- Electronic devices except non programmable calculators are not allowed in the Examination Hall.
Qn.No.1 to 3. Answer all questions. Each question carries 1 score. (3×1=3)
Choose the correctly matched pair.
a. Telocentric chromosome
– Middle centromere
b. Metacentric chromosome
-Centromere slightly away from the middle
c. Acrocentric chromosome
-Centromere close to its end
Choose the correct answer.
Law of limiting factors is proposed by
a. Cornelius Van Niel
c. Joseph Priestley
Observe the figure given below and identify the blue green alga.
Qn.No.4 to 11. Answer any 6 questions. Each question carries 2 scores.
Certain compounds formed during Krebs’ cycle are given below. Draw Krebs’cycle using the compounds.
Water from the root hairs move deeper into the root layers by two pathways. Name the two pathways. Which pathway is blocked in the endodermis? Give reason.
Analyse the table and fill in the blanks.
Artificial system and natural system are two systems of classification. Who are the proponents of these classifications.
Names of certain essential elements are given below:
Choose the macro nutrients and write one function of each of them.
Pili and fimbriae are surface structures seen in bacterial cells. Differentiate these structures.
Carbohydrates and fats are respiratory substrates. But their RQ is different. Define RQ. Write the RQ of these substrates.
Certain life cycle patterns of various plant groups are given below:
Choose the life cycle pattern shown by gymnosperms and angiosperms. Write the peculiarities of the identified life cycle pattern.
Qn. No 12 to 17. Answer any 5 questions. Each question carries 3 scores.
Observe the figure given below:
a. Source of which plant hormone is indicated in the figure.
b. Write four roles of the above identified hormone.
Observe the terms given below :
Vexillary, Axile, Marginal, Imbricate, Basal, Valvate.
Identify the three kinds of placentation from the above. Explain them.
Observe the figure.
a. Identify the above stage of mitosis.
b. Name the preceding stage of the above stage. Write its main events.
Observe the flow chart given below :
a. Identify A, B, C, Write the function of B.
b. Differentiate endarch and exarch xylem.
Observe the diagrammatic representation of Hatch and Slack pathway given below.
Identify the cells A and B. Explain the process of formation of C4 acid specifying the enzyme involved.
Periderm is constituted by three kinds of tissues. Name them. Write one peculiarity of each of them.
c. Acrocentric chromosome
-Centromere close to its end
Apoplast and Symplast pathways are two pathways.
Apoplast pathway is blocked in the endodermis.
Due to the presence of casparian strips / suberin thickenings.
a. golgi apparatus
b. basal body of cilia/ flagella/ spindle fibers
c. protein synthesis
Artificial system- Carl Linnaeus
Natural system – George Bentham and Joseph Hooker
Artificial system – based on external characters
Natural system – based on both external and internal characters
Potassium – anoin cation balance/opening and closing of stomata/maintain turgidity of cells.
Magnesium – maintain ribosome structure/ constituent of chlorophyll/activates enzymes of photosynthesis.
Pilli are elongated tubular structures. Fimbriae are small bristle like structures.
Ratio of volume of Co2 evolved to the ratio of oxygen absorbed is RQ.
RQ of carbohydrate is 1
RQ of fats are less than 1
Here diploid sporophytic phase is dominant.
In this type lifecycle the diploid sporophyte is the dominant, photosynthetic, independent phase of the plant. The gametophytic phase is represented by the single to fewcelled haploid gametophyte. This kind of lifecycle is termed as diplontic. All seed-bearing plants i.e., gymnosperms and angiosperms, follow this pattern.
b. Initiate rooting in stem cuttings
Control xylem differenciation
Cause apical dominance
Axial, Marginal and Basal
Axial : placenta is axial and ovules attached to it.
Marginal : Ovules are at margines of car-pels
Basal : Placenta at base of ovary
b. Preceding stage – Metaphase .
Chromosomes are highly condensed they are arranged at equatorial plane.
a. A – Parenchyma
B – Collenchyma
C – Sclerenchyma
Function of B – Give support
b.Endarch – protoxylem pointing towards centre
Exarch – Protoxylem pointing towards periphery
B – Bundle sheath cell
The primary Co2 acceptor is a 3-carbon molecule phosphoenol pyruvate (PEP) and is present in the mesophyll cells. The enzyme responsible for this fixation is PEP carboxylase or PEPcase. It is important to register that the mesophyll cells lack Ru- BisCO enzyme. The C4 acid OAA is formed in the mesophyll cells. It then forms other 4-carbon compounds like malic acid or aspartic acid in the mesophyll cells itself, which are transported to the bundle sheath cells. In the bundle sheath cells these C4 acids are broken down to release Co2 and a 3-carbon molecule. The 3-carbon molecule is transported back to the mesophyll where it is converted to PEP again, thus, completing the cycle. The Co2 released in the bundle sheath cells enters the C3 or the Calvin pathway, a pathway common to all plants. The bundle sheath cells are rich in an enzyme Ribulose bisphosphate carboxylase-oxygenase (RuBisCO), but lack PEPcase. Thus, the basic pathway that results in the formation of the sugars, the Calvin pathway, is common to the C3 and C4 plants.
Phellum, phellogen and phelloderm are the three kinds of tissue.
One type of meristematic tissue called cork cambium or phellogen develops, usually in the cortex region. Phellogen is a couple of layers thick. It is made of narrow, thin-walled and nearly rectangular Cells. Phellogen cuts off cells on both sides. The outer cells differentiate into cork or phellem while the inner cells differentiate into secondary cortex or phelloderm. The cork is impervious to water due to suberin deposition in the cell wall. The cells of secondary cortex are parenchymatous. Phellogen, phellem, and phelloderm are collectively known as periderm.