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Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 8 Biodiversity and Conservation.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 8 Biodiversity and Conservation

Question 1.
Gopalan cultivated a variety of fruit crops and plants in this field and Raman destroyed the fruit crops and plants and cultivated rubber trees which are double in number. (MARCH-2010)
a) In your opinion which method is suitable for the ecosystem? Give reason.
b) Mention any three factors for the extinction of species.
Answer:
Method by Gopalan
Biodiversity depends on variety of species.  Extinction of species is due to

1. Over exploitation
2. Habitat loss and fragmentation
3. Co-extinction

Question 2.
a) The “Evil Quartet” is the nickname used to describe the causes of biodiversity losses. Explain the reason leading to accelerated rates of extinction of flora and fauna.  (MAY-2010)
b) Philosophically or spiritually, we need to realize that every plant or animal species has an intrinsic value and we have a moral duty to protect them. Justify the statement and write down the protective measures.
Answer:
a) (1) Habitat loss and fragmentation
(2) Over-exploitation
(3) Alien species invasions
(4) Co-extinction
b) Agreed with the statement as we have a moral duty to care for their well-being and pass on our biological legacy in good order to future generations.
Protective measures-
Insitu conservation – Biosphere reserve, National park, Wild Life Sanctuary etc.
Exsitu conservation – Zoo, Botanical gardens, seed bank etc.

Question 3.
The year 2010 has been declared as the International Biodiversity Year by United Nations (UN)  (MARCH-2011)
a) Point out the levels of diversity in nature.(1 Score)
b) Give a brief description of The Evil Quartet.
Answer:
a) Genetic, Species, Ecosystem level diversity.
b) i) Habitat loss and fragmentation
ii) Overexploitation
iii) Alien species Invasion
iv) Co-extinction etc.

Question 4.
The given graph shows the distribution of insects in different latitudes of earth.  (MARCH-2012)

a) What is your observation?
b) List the three reasons for greater biodiversity in tropical regions.
c) Write two causes of biodiversity lossess.
Answer:
a) Species richnes decreases from equator to poles.
b) Climate is constant and predictable Glaciations were absent. Tropical region get more solar energy.
c) Habital loss and fragmentation Invansion of alien species.

Question 5.
Last twenty years alone have witnessed the disappearance of 27 animal species from earth.  (MAY-2012)
a) Name an animal disappeared recently.
b) What may be the causes for this loss?
c) How can we conserve biodiversity?
Answer:
a) Out of Syllabus
b) i) Habitat loss and fragmentation
ii) Over-exploitation
iii) Alien species invasions
iv) Co-extinctions
c) It is through in situ (on site) conservation and ex situ (offsite) conservation

Question 6.
Gopalan cultivated a variety of fruit crops and plants . in this field and Raman destroyed the fruit crops and plants and cultivated rubbertrees which are double in number.  (MARCH-2013)
a) In your opinion which method is suitable for the ecosystem? Give reason.
b) Mention any three factors for the extinction of species.
Answer:
Method by Gopalan
Biodiversity depends on variety of species. Extinction of species is due to
1. Over exploitation
2. Habitat loss and fragmentation
3. Co-extinction

Question 7.
While preparing the species area relationship graph of 4 areas, the following z values are obtained.  (MAY-2013)
Area A = 0.1 Area B = 0.8 Area C = 1.2 Area D = 0.3
a) Which area shows maximum species richness?
b) What are the expected reasons for the loss of biodiversity in areas with low species richness?
Answer:
a) Area a = 0.1
b) (i) Habitat loss and fragmentation
(ii) Over-exploitation
(iii) Alien species invasions
(iv) Co-extinctions

Question 8.
“Nature provides all for the need of man but not for his greed.” (MARCH-2014)
a) Do you agree with this statement? Justify your answer.
b) Distinguish between two types of biodiversity conservations.
Answer:
a) yes, For example forest is used for some basic needs of a man but not for clearing of trees .
b) Exitu conservation – conservation of flora and fauna outside the natural habitat
Eg- Botanical garden
Insitu conservation – conservation of flora and fauna in the natural habitat
Eg-wild life sanctuaries and national parks

Question 9.
a) Variety of species are present around us, what they constitute and comment.  (MAY-2014)
b) Comment on in situ conservation and ex situ conservation.
c) In these aspects explain biodiversity hot spots with example – give importance to recent issues with regard to Western Ghats.
Answer:
a) Biodiversity
b) Exitu conservation – conservation of flora and fauna outside the natural habitat Insitu conservation- conservation.of flora and fauna in the natural habitat
c) Biodiversity hotspots are regions with very high levels of species richness and high degree of endemism Western ghats is the hotspots where accelerated habitat loss occurs.

Question 10.
We have a moral responsibility to take good care of earth’s biodiversity and pass it on in good order to next generation.  (MARCH-2015)
a) Define Biodiversity.
b) Write causes for biodiversity losses.
c) Name two types of biodiversity conservation.
Answer:
a) It is the variety within and between all species of plants, animals and micro-organisms and the ecosystems within which they live and interact.
b) i) Habitat loss and fragmentation
ii) Over-exploitation
iii) Alien species invasions
iv) Coextinctions
c) Insitu conservation, Exitu conservation

Question 11.
Two approaches for the conservation of biodiversity is shown as A and B.  (MAY-2015)

a) Identify the type of biodiversity conservation shown in A and B.
b) Write the difference between the two, types of biodiversity conservation shown in A and B.
c) Which of the above approach is more desirable’ when there is an urgent need to save a species?
Answer:
a) A-Insitu conservation B-Exitu conservation
b) A- It is the conservation of animals in natural habitat
B- It is the conservation of plants outside the natural habitat
c) exitu conservation

Question 12.
Observe the concept diagram of the Evil Quartet of biodiversity loss. (MARCH-2016)

a) Write A and B
b) What is Co-Extinction?
Answer:
a) A- Habitat loss and fragmentation
B -Alien species invasions
b) When a species becomes extinct, the plant and animal species associated with it also become extinct

Question 13.
Read the statement and choose the correct option:   (MARCH-2016)
A: Sacred grooves are examples of in situ conservation
B: Biodiversity hotspots have low degree of endemism.
C: Biodiversity increases when number of organisms in a particular species increases.
a) Statement ‘A’ alone is correct
b) Statement ‘A’ and ‘B’ are correct
c) Statement ‘A’ and ‘C’ are correct.
d) Statement ‘C’ alone is correct
Answer:
Statement ‘A’ alone is correct.

Question 14.
a) “When we conserve and protect the whole ecosystem, its biodiversity at all levels is protected.” Based on this statement explain the strategies of biodiversity conservation.  (MAY-2016)
OR
b) “When need turns to greed, it leads to biodiversity loss.” Substantiate this statement by explaining two causes of biodiversity loss.
Answer:
a) Insitu conservation- It is the conservation of plant and animal sp. in their natural habitat.
Eg-biosphere reserves, national parks and sanctuaries.
Exitu conservation- It is the conservation of plant and animal sp outside the natural habitat.
Eg- Zoological parks, botanical gardens and wildlife safari parks.
OR
b) i) Habitat loss and fragmentation: The degradation of many habitats by pollution affects the survival of many species. It results large habitats are broken up into small fragments.
Amazon rain forest is cleared for cultivating soya beans or for conversion to grasslands for raising beef cattle
ii) Over-exploitation : It leads to the over-exploitation of natural resources. For example the extinction of Steller’s sea cow, passenger pigeon was due to humans.
iii) Alien species invasions : The introduction of foreign species cause the reduction or extinction of indigenous species.
The Nile perch introduced into Lake Victoria in east Africa led to the extinction of more than 200 species of cichlid fish in the lake
iv) Co-extinctions : If two species are in obligatory relationship the extinction of one species affect the other.
Eg – coevolved plant-pollinator mutualism where extinction of one species leads to the extinction of the other.

Question 15.
Z – values of a frugivorous bat species are given below. Which value is not applicable to continents?  (MARCH-2017)
1) 0.6
2) 0.65
3) 0.20
4) 0.68
Answer:
Incorrect option

Question 16.
Distinguish in situ conservation from ex situ conservation with one example each.  (MARCH-2017)
Answer:
Insitu conservation- Ms the conservation of plant and animal sp. in natural habitat.
Eg- biosphere reserves, national parks and sanctuaries.
Exitu conservation- It is the conservation of plant and animal sp outside the natural habitat.
Eg- Zoological parks, botanical gardens and wildlife safari parks.

Question 17.
What are the advantages of biofertilizers over chemical fertilizers? Give an example for biofertilizer.  (MARCH-2017)
Answer:
a) 1) It prevents pollution
2) It improves soil structure and function
b) biofertilizer- Mycorrhiza

Question 18.
Explain the three levels of biodiversity. (MAY-2017)
OR
Explain different types of biodiversity conservation with example.
Answer:
1. Genetic diversity – A single species might show high diversity at the genetic level over its distributional range
2. Species diversity – Diversity at species level
3. Ecological diversity – Diversity at ecosystem level
OR
In situ conservation – the species are protected in their natural habitat.
example: National Park, Wildlife sanctuaries etc.
ex situ conservation – threatened animals and plants are protected outside their natural habitat.
example: Zoological Park, botanical gardens etc.

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 7 Microbes in Human Welfare.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 7 Microbes in Human Welfare

Question 1.
Ramu cultivated pea plants as an intercrop in his paddy field. After harvesting, he allowed the roots of the pea plants remain in the soil for some period. (MARCH-2010)
a) Do you think the action of Ramu is reasonable?
b) Justify your answer.
Answer:
Yes.
Rhizohium found in the root nodules in the pea plant can fix atmospheric nitrogen into nitrates and in-creases fertility of soil.

Question 2.
Match column I with II. (MAY-2010)

Answer:

Question 3.
A bacterial infection was effectively controlled by using a specific anitibiotic for a long time. But nowadays this antibiotic is not found to be so effective to control the said infection. (MARCH-2011)
Give a scientific explanation for this phenomenon based on evolution.
Answer:
Evidence for Natural selection and explanations like origin of antibiotic resistant varieties or elimination of sensitive varieties or Natural selection by Anthropo-genic action.

Question 4.
Rearrange the columns B & C with respect to A. (MARCH-2012)

Answer:
Monascus – Statin – Cholesterol
Streptococcus – Streptokinase – Cholestrol lowering
Pencillium – Penicillin – Antibiotic
Trichoderma – Cyclosporin-A – Immuno suppressant

Question 5.
Match the following (MAY-2012)

Answer:
(A) – (3)
(B) – (2)
(C) – (1)
(D) – (5)

Question 6.
Some bioactive molecules, their source and their medical impotance are given in the table below. Fill up the missing parts. (MARCH-2013)

Answer:
a) streptokinase
b) Trichoderma polysporum
c) Immunosuppressant in organ transplant patients
d) Statins

Question 7.
Complete the illustration appropriately. (MAY-2013)

Answer:
a) Biofertilisers
b) Yeast,ethanol production,
c) (1) Lady bird and dragon flies are useful in the elimination of aphids and mosquitoes.
(2) Bacillus thuringiencis
d) Dough for making dosa and idly is fermented by Bacteria.

Question 8.
The meaning of ‘antibiotics’is ‘against life’, whereas with reference to human beings they are ‘pro life’. Substantiate the statement with suitable example. (MARCH-2014)
Answer:
Penicillin was widely used to kill bacteria during infection.
During second world war,it was widely used to treat soldiers against bacterial infection

Question 9.
In our state waste managenfient is a problem. Government promotes and give subsidy to Biogas plants. Comment the functioning of biogas plants with the help of microbes. (MAY-2014)
Answer:
Methanobacterium is used to produce biogas and can be used as source of energy as it is inflammable. It is an anaerobic bacterium used in sludge digesters.

Question 10.
Microbes can also be used as a source of energy. (MARCH-2015)
Substantiate with suitable examples.
Answer:
Methanobacterium is used to produce biogas and can be used as source of energy as it is inflammable.

Question 11.
BOD of some water samples are given below: (MAY-2015)
A. Sample 1 – 200 mg/L
B. Sample 2 – 80 mg/L
C. Sample 3 – 300 mg/L
D. Sample 4 – 25 mgIL
a) Which of the above water sample is most polluted?
b) What is meant by floes ? What is its role in sewage treatment?
Answer:
a) Sample 4
b) Floes- masses of bacteria associated with fungal filaments to form mesh like structures.
They consume the major part of the organic matter in the effluent. This is significantly reduces the BOD of the effluent.

Question 12.
“BOD is commonly calculated as an index of water pollution”. (MARCH-2016)
a) Do you agree with this statement? Why?
b) Expand BOD.
Answer:
a) Yes, if pollution load increases ,BOD increases
b) biochemical oxygen demand

Question 13.
Choose the correct answer from the bracket. (MAY-2016)
Cyclosporin A is produced by ______
a) Aspergellus
b) Clostridium
c) Trichoderma
d) Acetobacter
Answer:
Trichoderma

Question 14.
Select a bio-control agent from the given microbes: (MAY-2016)
a) Baculo virus
b) Rhino virus
c) Picrona virus
d) Adenovirus
Answer:
a) Baculovirus

Question 15.
Complete the table by filling A, B, C and D using hints from the bracket:  (MAY-2017)
(Gobargas, Biological Control, Anabaena, Saccharomyces cerevisiae, Propionibacterium
sharmanii)

Answer:
A -Gobargas
B – Saccharomyces cerevisiae
C – Anabaena
D-Biological control

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 6 Human Health and Disease.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 6 Human Health and Disease

Question 1.
“More and more children in Metro cities of India suffer from allergies and asthma.” (MARCH-2010)
a) Do you agree with this statement?
b) Justify your answer.
Answer:
a) Yes
b) Absence of previous encounter with the allergies in the over protected environment reduces immunity and children become more prone to allergy/ over exposure to allergens or pollutants in the metro cities can be considered.

Question 2.
Widespread incidence of diseases like H₁H₁, Chikungunya, dengue fever etc. are reported recently. As a science student, prepare an action plan in your school to control those diseases. (MARCH-2010)
Answer:
Measures to control mosquitoes, precaution to prevent the spread of disease. Awareness campaign for students etc.

Question 3.
The flow chart given below represents the life cycle of malarial parasite. Complete the flow chart and answer the following: (MAY-2010)

a) Which species of malarial parasite causes malignant malaria ?
b) Can you suggest two methods to control malaria?
Answer:
2 – Liver, 4 – RBC
a) Plasmodium falci parum
b) 1. Public hygiene and proper waste disposal
2. Periodic cleaning and disinfection of water reservoirs
3. Control of mosquitoes and their breeding grounds (any methods to control insect vectors can be added)

Question 4.
The list given below includes various stages of HIV infection. Arrange them according to correct sequence. (MAY-2010)
Answer:
Viral replication – Macrophage – Helper T cell – Formation of DNA – Progeny Virus – Viral particle – Release of progeny virus

Question 5.
Lakshmi and Sujitha are two Nursery students. Sujitha gets common cold very often. Lakshmi not (MARCH-2011)
a) How do you interpret this in an immunological aspects?
b) What are the common barriers protecting Lakshmi from cold?
Answer:
a) Low level of innate or weak or poor immunity to Sujitha / High immunity to Lakshmi.
b) Two correct points (Physical, Physiological, Cellular and Cytokine barriers) like mucous membrane / Nostril hairs / skin / Antibodies / Interferons.

Question 6.
Arrange the following diseases in the following columns in a meaningful order.  (MARCH-2012)
Typhoid, Ringworms, Amoebiasis, AIDS, Malaria, Pneumonia, Common cold.

Answer:

Question 7.
In a classroom discussion a student argues that allergic diseases are more common in children of metrocities than in villages. ,  (MARCH-2012)
a) Do you agree with this statement.
b) Which type of immunoglobulin is responsible for allergic reactions?
c) Suggest two drugs which reduce allergic symptoms.
Answer:
a) Yes
b) IgE
c) Antilistamine and Adrenalin drugs

Question 8.
Note the relation between first two terms and suggest a suitable term for the fourth place. (MAY-2012)
a) Erythroxylum coca : cocaine :
Papaversomniferum : _______
b) Salmonella typhi: typhoid :
Plasmodium falciparum: ______
Answer:
a) morphine
b) malaria

Question 9.
Nature has as many varieties of plants which give drugs for abuse, as there are medicinal plants which give medicines. Substantiate with two examples. (MARCH-2013)
Answer:
a) Cocaine is obtained from coca plant Erythroxylum coca. It affects the transport of the neuro-transmitter dopamine.
b) Opioids are the drugs, receptors present in our central nervous system and gastrointestinal tract Heroin (smack the depressant,it is prepared by the acetylation of morphine which is extracted from the latex of poppy plant Papaversomniferum.

Question 10.
“Prevention is better than cure”. This statement is true in the case of AIDS as well as immunisation. Substantiate. (MAY-2013)
Answer:
Diseases like AIDS are not curable even after the treatment for long period. This is the immuno deficiency disease affect the resistant power of the body. Medicine for these diseases are not discovered so far. Likewise immunization is done in earlier period of growth is good .Hence prevention is better than cure.

Question 11.
Classify the diseases given in the box as two groups based on their causative organisms. Specify the type of causative organism for each group. (MARCH-2014)

Answer:
protozoans – Malaria and amoebiasis Bacterial — diphtheria, typhoid and pneumonia

Question 12.
Prepare a pamphlet for an awareness programme in your school about the measures to prevent and control alcohol and drug abuse in adolescents. (MARCH-2014)
Answer:
Education and counseling, moral education, Avoid undue peer pressure, visual publicity through TV, seeking professional and medical help etc.

Question 13.
Briefly describe the characteristics of cancer cells. (MAY-2014)
Answer:
1. lose of contact inhibition- Normal cells are contact with other cells inhibits their uncontrolled growth. Cancer cells lost this property.
2. Metastasis- Cells sloughed from tumors reach distant sites through blood, and wherever they get lodged in the body, they start a new tumor there.

Question 14.
It is said that “Chikunguinea” once affected will not affect a person in the next half of his life. Justify this statement. (MAY-2014)
Answer:
This is due to acquired immunity. Due to infection body first time produces a response called primary response which is of low intensity. Subsequent encounter with the same pathogen a highly intensified secondary response. This is appears to have memory of the first encounter. The primary and secondary immune responses are carried out with the help of two special types of lymphocytes present in our blood, i.e. B-lymphocytes and T- lymphocytes.

Question 15.
Mother’s milk is considered essential for new born infants. (MARCH-2015)
a) Name the fluid secreted by mother from breast during the initial days of lactation.
b) What type of immunity it provides?
Answer:
a) Colostrum
b) IgA provides passive immunity

Question 16.
Cancer is one of the most dreaded diseases of human beings, and is a major cause of death all over the globe. (MARCH-2015)
a) What are the causes of cancer?
b) What are the methods of detection of cancer?
c) What are the types of treatment for cancer?
Answer:
a) Ionising radiations like X – rays and gamma rays and non-ionizing radiations like UV cause DNA damage leading to neoplastic transformation. The chemical carcinogens present in tobacco smoke have been identified as a major cause of lung cancer.

b) Biopsy and histopathological studies of the tissue and blood and bone marrow tests for increased cell counts in the case of leukemias Radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs

c) 1. Surgery, radiation therapy and immuno therapy
2. Chemotherapeutic drugs are used to kill cancerous cells

Question 17.
Match the terms given in the three columns of the table correctly: (MAY-2015)

Answer:
Haemophilus Influenzae – Bacteria – pneumonia
Plasmodium Vivax – protozoa – malaria Wuchereria
Bancrofli – flat worm – filarisis
Trichophyton – fungus – ringworm

Question 18.
Identify the disease shown in the following figure and write the causative organism of the disease.(MARCH-2016)

Answer:
Elephantiasis orfilariasis

Question 19.
“Blood of a man is tested positive for cannabinoid.” (MARCH-2016)
a) What are these?
b) From where these are extracted naturally?
c) Which part of the body is affected by these?
Answer:
a) Drug obtained from plants
b) Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa
c) Cardiovascular system of the body

Question 20.
Breast feeding during initial period of infant growth is necessary to develop immunity of new born babies. Why? (MARCH-2016)
Answer:
Initial days of lactation contains colostrum which is rich in antibodies and provide immunity to new borne babies.

Question 21.
Answer the questions about the given figure: (MAY-2016)

a) Identify the parts X and Y.
b) Name any two types of this molecule.
Answer:
a) X-antigen binding site
Y-Heavy chain
b) lgA, lgG, lg E

Question 22.
Select the odd one out and justify your selection. (MAY-2016)
Malaria, Gonorrhea, Amoebiasis, Filariasis
Answer:
Gonorrhoea – It is the only sexually transmitted disease

Question 23.
Complete the table by filling a, b, c and d. (MAY-2016)

Answer:
a) pneumonia
b) Rhino virus
c) malaria
d) Inflammation of lymphatic vessels of lower limb/ genital organs

Question 24.
Feeding _______ in the first few days is essential for preventing infections in a newly born baby. (MARCH-2017)
Answer:
colostrum

Question 25.
Morphine is said to be an abused drug. Discriminate the terms ‘use’ and ‘abuse’ of drugs based on this example. (MARCH-2017)
Answer:
For medical purpose it is used as painkiller or sedative but it is abused by some individuals as narcotic drug.

Question 26.
Differentiate Active immunity from Passive immunity. Give an example for Passive immunity. (MARCH-2017)
Answer:
When the antigens are coming in the form of living or dead microbes, the body of organism produce antibodies. This type of immunity is called active immunity.
When ready – made antibodies are directly injected to protect the body against foreign agents, it is called passive immunity.
Eg-Anti-venom.

Question 27.
Prepare a brief note to be presented in an awareness programme for adolescents about AIDS, their causes and preventive measures. (MAY-2017)
Answer:
AIDS-it is acquired immuno deficiency syndrome caused by virus called HIV It is mainly prevented by

Avoid sex with multiple partners
Use disposable needles and syringes
Ensure safe blood transfusion

Question 28.
Fill the boxes A, B, C and D. (MAY-2017)

Answer:
A – Acquired immunity
B – Physiological barrier
C -Cytokin barrier
D-passive immunity

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 5 Evolution.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 5 Evolution

Question 1.
Arrange the following in a hierarchical manner based on the period of their evolution. (MARCH-2010)
Homoerectus, Ramapithicus, Australopithicines, Homosapiens, Neanderthal man.
Answer:
Ramapithicus -> Australopithicines -> Homoerectus -> Neanderthalman -> Homosapiens

Question 2.
Fill the columns A and B using the items given below: (MARCH-2010)

(Lamarkism, Evolution of anthropogenic action, Geneflow by chance, varieties of marsupials in Australia, De Vries)
Answer:

Question 3.
The diagrams shown below represents the operation of natural selection on different traits. Observe the diagrams and answer the following : (MAY-2010)

a) Why graph C shows a marked difference from graph A.
b) What is the evolutionary significance of Directional Selection?
c) Mention the factors affecting gene frequency.
d) What is meant by founder effect?
Answer:
a) A is stabilizing selection and C is disruptive selection.
b) Peak shifted to one direction.
c) Gene migration
Genetic drift
Mutation
Genetic recombination
Natural selection
d) The effect where original drifted population becomes founders is called founder effect.

Question 4.
a) Arrange the given chemical compound in the sequential order as per the concept of origin of life. (Ammonia, Hydrogen, Protein, Nucleic acid, Amino acid) (MARCH-2011)
b) Correlate Miller’s experiment with this.
Answer:
a) Hydrogen -> Ammonia -> Amino acid -> Protein Nucleic acid
OR
b) Brief account of Miller’s Experiment / Labelled diagram of the experimental setup.

Question 5.
Note the relationship between the first pair and complete the second pair. (MARCH-2012)
a) Natural selection : Drawing ; Inheritance of acquired characters : ________.
b) Heart of vertebrates: homologous organs; Flippers of Penguin and Dolphin : _______.
Answer:
a) Lamarck
b) Analogous organs

Question 6.
An evolutionary process occurred in the evolution of marsupial mammals in Australia is given below. (MARCH-2012)

a) Name this evolutionary process.
b) Suggest another example for this phenomenon.
Answer:
a) Adaptive radiation
b) Darwins finches

Question 7.
Arrange the following examples under two heads viz- homologous organs and analogous organs. (MARCH-2013)
Forelimb of whale and bat,
Wings of butterfly and bat,
Heart of man and cheetah,
Eyes of Octopus and mammals
Answer:
Homologous organs
Forelimb of whale and bat Heart of man and cheetah
Analogous organs
Wings of butterfly and bat Eyes of octopus and mammals

Question 8.
Theory of chemical evolution is a version of theory of abiogenesis. Analyze the statement. (MARCH-2013)
Answer:
Oparin and Haldane proposed that the first form of life that arose from preexisting non-living organic molecules (e.g. RNA, protein, etc.) and it is followed by chemical evolution

Question 9.
A specific rat population was controlled for about a decade by a poison. After apopulation decline for about 10 years, the rat population was increased stabilized. (MAY-2013)

Resistance to poison is governed by a dominant autosomal gene ‘R’. In 1975 majority of the resistant animals are heterozygous at this locus (Rr).
a) What was the major genotype of the rat population before 1961 ?
(A) RR, (B) Rr, (C) rr, (D) R is absent as it is produced by a mutation.
b) What explanation you give for the development of resistance against poison in these rats?
c) This illustration can be utilized to explain a theory of Evolution” Substantiate.
Answer:
a) R is absent as it is produced by mutation
b) Mutation leads to genetic variation and which in turn lead to evolution
c) Evolution by anthropogenic action

Question 10.
Given below is the diagrammatic representation of the operation of Natural Selection on different traits. (MARCH-2014)

a) Identify the type of natural selection A, B and C with explanation of each.
b) Define Hardy – Weinberg Principle.
Answer:
a) A- Stabilising selection-More individuals acquire mean character value
B – Directional selection – More individuals ac-quire value other than mean character
C – Disruptive selection – More individuals acquire peripheral character value at both ends.
b) According to Hardy-Weinberg principle allele frequencies in a population are stable and is con-stant from generation to generation. This is called genetic equilibrium. Sum total of all the allelic frequencies is 1.
Hence,p2 + 2pq + q2 = 1 Disturbance in Hardy- Weinberg equilibrium, i.e., change of frequency of alleles in a population affected by five factors These are gene migration or gene flow, genetic drift, mutation, genetic recombination and natural selection.

Question 11.
Arrange the following in a hierarchical manner in ascending order based on the period of their evolution.  (MAY-2014)Homoerectus, Ramapithecus, Australopithecus, Homo sapiens.
Answer:
Ramapithecus —> Australopithecus—>Homoerectus —> Homo sapiens

Question 12.
a) The diagram given below shows a particular type of evolutionary process in Australian marsupials. Identify the’ evolutionary phenomenon and comment on. (MAY-2014)

b) Give another example for such a type of evolutionary process and explain.
Answer:
a) convergent evolution
Number of marsupials are different from the other evolved from an ancestral stock, but all within the Australian island continent. When more than one adaptive radiation appeared to have occurred in an isolated geographical area(representing different habitats), it is called as convergent evolution.
b) Placental mammals in Australia also exhibit adaptive radiation in evolving into varieties of such placental mammals each of which appears to be ‘similar’ to a corresponding marsupial (e.g., Placental wolf and Tasmanian wolf marsupial).

Question 13.
Match the following: (MARCH-2015)

Answer:

Question 14.

The above shown pictures are beaks of a particular type of bird seen in an island during Darwin’s journey.  (MARCH-2015)
a) Identify the bird and name the island.
b) Write the significance of this process in evolution.
Answer:
a) Darwin’s Finches, Galapagos Islands
b) From the original seed-eating features, many other forms with altered beaks arose, enabling them to become insectivorous and vegetarian finches.

Question 15.
Four groups of organs are given below:  (MAY-2015)
Read them carefully and answer the questions:
A. Thorns of bougainvilla and Tendrils of cucurbita
B. Eyes of octopus and mammals
C. Flippers of penguin and dolphin
D. Forelimbs of cheetah and man
(a) Categorise the four groups of organs as homologous organs and analogous organs.
(b) Based on each group of organs differentiate convergent evolution and divergent evolution.
(c) Illustrate homologous and analogous organs as evidences for evolution.
OR
Observe the diagrammatic representation and answer the questions:

a) Explain the phenomenon shown in the figure.
b) How can it be considered as an evidence of evolution?
c) Write any other example for this phenomenon. Explain.
Answer:
a) Homologous organs
Thorns of bougainvilla and tendrils of cucurbits , fore limbs of cheetah and man Analogous organs: Eye of octopus and mammals, flippers of penguin and dolphin
b) Convergent evolution – different structures evolving for the same function
Divergent evolution – same structure developed for different function
c) In convergent evolution, the similar habitat that has resulted in selection of similar adaptive fea-tures in different groups of organisms but toward the same function:
In divergent evolution ,same structure developed along different directions due to adaptations to different needs
OR
a) Adaptive radiation
b) A number of marsupials, each different from the other evolved from an ancestral stock, but all within the Australian island continent. When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing different habitats), it represents convergent evolution.
c) Darwin’s finches represent one of the best examples of this phenomenon. From the original seed-eating features, many other forms with altered beaks arose, it helps them to become insectivorous and vegetarian finches.

Question 16.
Which theory talks about the huge explosion that leads to origin of universe?  (MARCH-2016)
Answer:
Big Bang theory

Question 17.
Read the principle and answer the questions: “Allele frequencies in a population are stable and constant from generation to generation called genetic equilibrium.’ (MARCH-2016)
a) Name the principle mentioned here.
b) Mention any two factors affecting the equilibrium.
c) What is the significance of disturbances occur in the genetic equilibrium?
OR
’Natural selection can lead to stabilisation, directional change and disruptive changes.’
Explain the terms stabilization, directional change and disruptive change mentioned above.
Answer:
a) Hardy-Weinberg principle
b) gene flow and genetic drift
c) they become a different species
OR
Natural selection can lead to 1 stabilisation (in which more individuals acquire mean character value)
2. directional change (more individuals acquire value other than the mean character value)
3. disruption (more individuals acquire peripheral character value at both ends of the distribution curve)

Question 18.
Observe the diagram and answer the questions below: (MAY-2016)

a) Identify the types of evolution in the concept diagrams A and B.
b) Write example pair each for homologous and analogous organs.
Answer:
A – Divergent evolution
B – Convergent evolution
Homologous organs- Cheetah and human – bones of forelimbs, thorn of Bougainvillea and tendrils of cucurbits.
Analogous organs – eye of the octopus and of mammals and flippers of Penguins and Dolphins.

Question 19.
Statement below show the features of some human fossils. Read carefully and identify the fossil. (MAY-2016)
a) Human like beings with brains capacities between 650 – 800 cc
b) Lived in East and Central Asia with brain capacity of 1400 cc.
Answer:
a) Homohabilus
b) Neaderthal man

Question 20.
A population of 208 people of MN blood group was sampled and it was found that 119 were MM group, 76 MN group and 13 NN group. Answer the following questions: (MARCH-2017)
a) Determine the gene frequencies of M and N alleles in the population.
b) How does the above frequencies affect evolution?
OR
Examine the pictures of Darwin’s Finches given below and answer the following questions:
a) What phenomenon in evolution is represented in the picture?
b) Explain the phenomenon with the help of an additional example.

Answer:
a) Adaptive radiation –In this evolution starting from a point and radiating to other areas of geography
b) A number of different marsupials evolved from an ancestral stock within the Australian island.

Question 21.
Which of the following sets of gases were used in Mliller’s experiment? (MARCH-2017)
1) \(\mathrm{CH}_{4}, \mathrm{NO}_{2}, \mathrm{H}_{2} \mathrm{O}, \mathrm{CO}_{2}\)
2) \(\mathrm{NH}_{3}, \mathrm{CH}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{H}_{2}\)
3) \(\mathrm{NH}_{3}, \mathrm{CH}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{H}_{2}\)
4) \(\mathrm{H}_{2} \mathrm{O}, \mathrm{N}, \mathrm{CH}_{4}, \mathrm{H}_{2}\)
Answer:
2) \(\mathrm{NH}_{3}, \mathrm{CH}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{H}_{2}\)

Question 22.
Diagrammatic representation of the operation of Natural Selection on different traits is given. Observe it and answer the questions: (MAY-2017)

a) What do B and C represent?
b) Explain the process shown in B and C.
Answer:
a) B is directional selection C is disruptive selection
b) B natural selection leads to directional change in which more individuals acquire value other than the mean character value.
C natural selection leads to disruption in which more individuals acquire peripheral character value at both ends of the distribution curve.

Question 23.
Rearrange the following in the order of their evolution period (MAY-2017)
Australopithecines
Neanderthal man
Homo sapiens
Homo erectus
Dryopithicus
Answer:
Dryopithecus —> australopithecus —> Homo erectus —> neanderthal man —> Homo sapiens

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 4 Molecular Basis of Inheritance.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 4 Molecular Basis of Inheritance

Question 1.
Observe the diagram below: (MAY-2010)

Which among the following is the complimentary sequence of the DNA fragment shown above?
a) 5′ -> ATTCG -> 3′
b) 3′ -> ATTCG -> 5′
c) 3′ -> TAAGC -> 5′
d) 3′ -> CGAAT -> 5′
Answer:
3′ -> TAAGC -> 5′

Question 2.
DNA sequence is provided below:   (MAY-2010)
TACGAGTTATATATACAT
a) Write down the triplet codon- it codes for.
b) If a nitrogen base is added in between 4th & 5th nitrogen bases, what will be its effect on transcription?
Answer:
a) AUG / CUC / AAU / AUA / UAU / GUA
OR
TAC / GAG / TTA / TAT / ATA / CAT
b) Frame shift mutation / point mutation/Mutation / Entire amino acid sequence changed / incorrect protein produced / change in protein structure / incorrect transcription and translation /abnormal protein.

Question 3.
In a paternity dispute, the VNTR DNA samples of parent and child were DNA finger printed. The diagrammatic representation of the DNA fingerprint is shown below.  (MAY-2010)

a) What is your opinion about the paternity of child? Substantiate your opinion.
b) List down any four major steps of molecular biological procedures adopted for this.
Answer:
a) Paternity is confirmed
VNTR bands / finger print bands / bands are similar.
b) Steps of DNA finger printing techniques are
i) Isolation of DNA
ii) Digestion of DNA by restriction endo nuclease
iii) Seperation of DNA fragment by Electrophoresis,
iv) Plotting of DNA fragment into Nitro cellulose
v) Ditection of hybridised DNA by Auto radiography

Question 4.
A transcriptional unit is given below. Observe it and answer the questions.  (MARCH-2012)

a) How can you identify the coding strand?
b) Write the sequence of RNA formed from this unit?
c) What would happen if both strands of the DNA act as templates for transcription?
Answer:
a) Coding strand has 5′ end at the promoter or 5’TCAGTACA3′
b) 5′ UCAGUACA 3′
c) The two RNA will be complimentary and may form double stranded RNA and it prevents the translation.

Question 5.
In E.coli lactose catabolism is controlled by Lac operon. Lac operon in the absence of inducer (lactose) is given below. (MARCH-2012)

a) What is ‘P’?
b) Name the enzymes produced by the structural genes ‘Z’, ‘Y’ and ‘a’?
c) Redraw the diagram in the presence of an inducer.
Answer:
a) Promoter
Z-Bgalactosidase
b) Y – Permease
a-Transacetylase
c)

Question 6.
Following are the first two steps in Griffith transformation experiment: (MAY-2012)
1) S strain 2 Inject into mice 2 mice live
2) R strain 2 Inject into mice 2 mice die
a) If there is any mistake correct it.
b) Write the remaining steps.
Answer:
a) 1. S strain -> inject into mice -> mice die
2. R strain inject into mice -> mice live
b) When Griffith was injected heat-killed S strain into mice, bacteria did not kill them. But he injected a mixture of heat-killed S and live R bacteria, the mice died .

Question 7.
DNA is better genetic material than RNA. Do you agree with this statement ? Substantiate. (MAY-2012)
Answer:
The 2-OH group present at the nucleotide in RNA is a reactive group and makes RNA labile and easily degradable. Hence DNA is less reactive and structurally more stable when compared to RNA. Therefore, among the two nucleic acids, the DNA is a better genetic material.

Question 8.
Given below is the diagrammatic representation of first stage of a process in bacteria. (MAY-2012)

a) Identify the process.
b) Name the enzyme catalyses this process.
c) What are the additional complexities in Eukaryotes for this process?
Answer:
a) Prokaryotic transcription
b) RNA polymerase
c) In eukaryotes hnRNA undergo additional processing called as splicing, capping and tailing.
In splicing the introns are removed and exons are joined together. In capping methyl guanosine triphosphate is added to the 5-end of hnRNA. In tailing, adenylate residues are added at 3-end in a template.The fully processed hnRNA, called as mRNA, that is transported out of the nucleus for translation.

Question 9.
The flow of genetic information is shown below. (MARCH-2013)

Name the processes a, b, c
Answer:
a) Replication
b) Transcription
c) Translation
d) Reverse transcription

Question 10.
RNA is not an ideal molecule as genetic material because ________. (MARCH-2013)
a) 2’OH group of ribose is reactive and make it labile
b) It is catalytic and hence reactive
c) Both (a) and (b)
d) None of the above
Answer:
c) Both a and b

Question 11.
Presence of lactose enhances the production of (3 galactosidase and other enzymes in bacteria, how will you explain this phenomenon? (MAY-2013)
Answer:
In lac operon,lactose is the inducer.Inducer binds with repressor protein but repressor cannot bind to op-erator gene,the free operator gene induces the RNA polymerase to bind with promoter and initiates tran-scription Three structural genes synthesise three mRNAs to produce enzymes.

Question 12.
A DNA sequence needed for coding a peptide is given below. (MAY-2013)
CAAGTAAATTGAGGACTC
(Hint: Codons and Aminoacids)
CAAGTAAATTGAGGACTC
UUA-Leu
CCU – Pro
CAU – His
ACU-Thr
GUU-Val
GAG-Glu
a) Write the complementary mRNA coding sequence for this.
b) Find out the amonoacid sequence of the peptide chain using the codons given in the hints.
c) If a mutation cause a change in the sixth codon CTC to CAC. It leads to a mendelian disorder. Identify the disease and write the specific characteristics of the diseasie.
Answer:
a) GUUCAUUUAACUCCUGAG
b) Val,His,Leu,Thr,Pro,Glu
c) Sickle cell anaemia, RBC become sickle shaped and unable to take oxygen .These are destroyed more rapidly leading to anaemia.

Question 13.
Draw a flow chart showing the steps of southern blot hybridization using radio labelled VNTR. (MAY-2013)
Answer:

Question 14.
“Prediction of the sequence of amino acids from the nucleotide sequence in mRNA is very easy, but the exact prediction of the nucleotide sequence in m RNA from the sequence of amino aids coded by mRNA is difficult”.(MARCH-2014)
a) Which properties of the genetic code is the reason for the above condition? Explain.
b) Which are the stop codons in DNA replication?
Answer:
a) Degeneracy – A single aminoacid is represented by many codons (degenerate codons)
b) Stop codons are UAA,UAG,UGA

Question 15.
Diagrammatic representation of Central dogma’ is given below: Observe the diagram carefully and redraw it making appropriate corrections. (MARCH-2014)

Answer:

Question 16.
Explain the phenomenon shown in the following figure and the reason for difference in the production of  II recombinants in Cross A and Cross B as explained by morgan. (MARCH-2014)

Difference in chromosome number of some human beings A, B. C and D are given below:
A) 22 pairs of Autosomes
B) 22 pairs of Autosomes+XO
C) 22 pairs of Autosomes + 1 Autosome
D) 22 pairs of Autosomes+XXY
OR
a) Identify the person who suffers from Klinefelter’s syndrome. Write its symptoms.
b) Differentiate between aneuploidy and polyploidy.
Answer:
The percentage of cross over depends upon the distance between the genes.
The genes are closer in cross A,so the less number of recombinants are produced. This is called link-age.
In cross B, genes are distantly located so more number of recombinants are produced.
OR
a) 22 pairs of autosomes+XXY, Sterile male, poorly developed testis and mental retardation
b) Aneuploidy-failure of separation of chromosomes during cell division results in-the gain or loss of chromosome.
Polyploidy – Failure of cytokinesis aftertelophase results in the increase in a whole set of chromosome

Question 17.
Correct the amino acid sequence of sickle cell haemoglobin. (MAY-2014)

Answer:

Question 18.
Diagram of components of DNA are given below: Identify and differentiate the two diagrams I and II. (MAY-2014)

Answer:
I- Nucleotide II- Nucleoside

Question 19.
a) Identify the diagram and explain. (MAY-2014)

b) In same cases DNA is produced from RNA. Name this process and give example.
Answer:
a) Central Dogma in molecular biology
b) Reverse transcription

Question 20.
a) Define mutation. (MAY-2014)
b) What are the different types of mutation?
Answer:
a) Mutation is a phenomenon which results in alteration of DNA sequences and consequently results in changes in the genotype and the phenotype of an organism
b) physical mutation and chemical mutation

Question 21.
a) Paternity or maternity can be determined by certain scientific methods. What is it? Define. (MAY-2014)
b) Briefly write the* methodology involved in the technique.
c) Comment on its other applications.
Answer:
a) DNA fingerprinting. DNA fingerprinting involves identifying differences in some specific regions in DNA sequence
b) i) isolation of DNA
ii) digestion of DNA by restriction endonucleases
iii) separation of DNA fragments by electrophoresis
iv) transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon
v) hybridisation using labelled VNTR probe
vi) detection of hybridised DNA fragments by autoradiography
c) It is also used in forensic science

Question 22.
Fill in the blanks: (MARCH-2015)
a) _________is a metabolic disorder that occurs due to the lack of an enzyme, that converts phenylalanine to tyrosine.
b) _______is a disease caused by the substitution of Glutamic acid by valine at 6th position.

Answer:
a) Phenylketonuria
b) Sickle-cell anaemia

Question 23.
The flow of genetic information is shown below. Name the process of (a) and (b). (MARCH-2015)

Answer:
a) Trancription
b) Translation

Question 24.
Explain transcription. A transcription unit in DNA is defined primarily by three regions. Write the names of any two regions. (MARCH-2015)
Answer:
Information contained in DNA is copied down to mRNA is called Transcription – Promoter and structural gene.

Question 25.
Observe the diagram and answer the questions: (MAY-2015)

a) What is the difference in the replication processes in A strand and B strand?
b) What is the role of DNA ligase in the replication process in B strand?
c) What is meant by Replication fork?
Answer:
a) In A, replication is continuous and form leading strand but in B replication is discontinuous and form lagging strand.
b) In B, short stretch of Okazaki fragments are connected with the help of DNA ligase and form continuous strand
c) The replication occur within a small opening of the DNA helix, referred to as replication fork. It appears as Y shaped forked structure.

Question 26.
Observe the following diagram and answer the questions: (MAY-2015)

a) Diagrammatically represent the changes take place when lactose is added to the medium.
b) What is the role of z, y and a genes in this metabolic pathway?
Answer:
a)

b) The z gene codes for beta-galactosidase which is responsible for the hydrolysis of the disaccharide, lactose into galactose and glucose. The y gene codes for permease, which increases permeability of the cell to beta-galactosides.The a gene encodes a transacetylase

Question 27.
Read carefully the sequence of codons in the mRNA unit and answer the questions. (MARCH-2016)

a) What change in needed in the first codon to start the translation process?
b) If translation starts by that change, till which codon it can continuous? Why?
Answer:
a) AUG is needed
b) UGA, Termination of translation occurs

Question 28.
Schematic representation of DNA fingerprints are shown below: (MARCH-2016)

[Hints : C is a sample taken from a crime scene, A and B from two suspected individuals]
a) Which one of the suspected individual may involved in the crime?
b) Write any other use of DNA fingerprinting.
Answer:
a) suspected person is B
b) disputed parentage determining population and genetic diversities.

Question 29.
Observe the figure of mRNA and answer the questions: (MAY-2016)

a) Find the start and stop codons.
b) How many amino acids will be present in the protein translated from this mRNA?
c) The additional sequences that are not translated in mRNA are called _______.
Answer:
a) Start codon – AUG
Stop codon – UAG
b) 4
UTR- Untranslated region

Question 30.
a) The hints of the lac operon is given below: (MAY-2016)
Hints:
Inducer, Repressor,
Structural genes, operator Regulatory gene
i) Which substance is acting as inducer in this operon?
ii) Explain the working of operon in presence of the inducer.
OR
b) With the help of the figure given, explain the processing of hnRNA to mRNA in eukaryotes.

Answer:
a) i) lactose inducer
ii) If lactose is present in a medium, it has to be breakdown into glucose and galactose,for this positive control of operon works and structural genes transcribe. The switch on condition of operator gene is due to the binding of RNA polymerase with promotersite. In +ve control, repressor from regulator gene is inactivated due to the presence of lactose.
OR
b) 1) Splicing-the introns are removed and exons are joined together.
2) capping -methyl guanosine triphosphate is added to the 5-end of hnRNA.
3) Tailing- adenylate residues (200-300) are added at 3-end in a template
After these three process, fully processed mRNA is released from nucleus into cytoplasm for protein synthesis.

Question 31.
Examine the following fragment of beta globin chain in human haemoglobin and identify the hereditary disease with reason. (MARCH-2017)

Answer:
Sickle cell anaemia
The defect is caused by the substitution of Glutamic acid by Valine at the sixth position of the beta globin chain of the haemoglobin molecule The mutant haemoglobin molecule under low oxygen tension causing the change in the shape of the RBC from biconcave disc to elongated sickle like structure.

Question 32.
Which of the following combinations do not apply to DNA? (MARCH-2017)
a) Deoxyribose, Guanine
b) Ribose, Adenine
c) Deoxyribose, Uracil
d) Guanine, Thymine
1) (a) and (b)
2) (b) and (c)
3) (c) and (d)
4) (a) and (d)
Answer:
2) b) and c)

Question 33.
Examine the diagram of mRNA given below. Mark the ‘5’ and ‘3’ ends of the mRNA by giving reasons. (MARCH-2017)

Answer:
Polyadynilation always at 3′ end of m RNA ,so the other must be 5′ end.

Question 34.
A small fragment of skin of a different person was extracted from the nails of a murdered person. This fragment of skin led the crime investigators to the murderer. Based on this incident answer the following questions: (MARCH-2017)
1) What technique was used by the investigators?
2) What is the procedure involved in this technique?
OR
In an E. coli culture lactose is used as food instead of glucose. If so, answer the following questions:
1) How do the bacteria respond to the above situation at genetic level?
2) If lactose is removed from the medium what will happen?
Answer:
1) DNA finger printing
2) The technique, is based on following procedure
i) isolation of DNA,
ii) digestion of DNA by restriction endonucleases,
iii) separation of DNA fragments by electrophoresis,
iv) transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon,
v) hybridisation using labelled VNTR probe, and vi) detection of hybridised DNA fragments by autoradiography
OR
In this closely associated genes function as unit called operon If lactose is present in a medium, it has to be breakdown into glucose and galactose ,for this positive control of operon works and structural genes transcribe with the help of switch on condition of operator gene. This is due to binding of RNA polymerase on promoter site of DNA.

Question 35.
Find the odd one and write the common feature of others. (MAY-2017)
Cytidine, Adenine, Thymine, Guanine.
Answer:
Cytidine, All others are nitrogen bases.

Question 36.
Observe the diagram:  (MAY-2017)

a) Redraw the diagram correctly if any mistake is there.
b) What does the diagram indicate?
c) What is the function of DNA ligase in this process?
Answer:
a)

b) Replication fork.
c) Discontinuously synthesised fragments of DNA are joined by DNA ligase.

Question 37.
Read the codon sequence in the mRNA unit which is undergoing translation.  (MAY-2017)

a) What will happen if the nitrogen base ‘U’ in the sixth position is replaced by ‘A’ by point mutation?
b) Name and define this type of mutation.
c) Draw the base sequence in the coding DNA strand from which the above mRNA is transcribed.
Answer:
a) Translation stop as UAA is a stop codon.
b) In this point mutation one nitrogen base is deleted.
c)

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 3 Principles of Inheritance and Variation.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 3 Principles of Inheritance and Variation

Question 1.
Polypeptide chains of two haemoglobin molecules are shown below. One of the chains shows an abnormality. Observe the diagram and answer the following questions. (MARCH-2010)

a) Which of the polypeptide chain in haemoglobin is abnormal leading to a disease?
b) What is the reason for this abnormality?
c) What will be the effect of this change in polypeptide chain?
Answer:
a) A
b) Substitution of glutamic acid by valine in the 6th position of polypeptide chain.
c) The RBC become sickle shaped causing a disease sickle cell anaemia / Affect the o₂ carrying capacity of RBC.

Question 2.
To find out the unknown genotype of a violet flowered pea plant a researcher done the following cross. Observe the diagram and answer the following questions: (Hint: Violet flower colourin pea plant is dominant over white). (MARCH-2010)

a) What would be the above cross called?
b) Can you determine the unknown genotype of violet flowered parent by drawing Punnet square?
Answer:
a) Test cross
b)

Genotype of unknown parent Ww/ Heterozygous.

Question 3.
Some genetic abnormalities, their genotypes and features are distributed in columns A, B and C respectively. Match them correctly. (MAY-2010)

Answer:

Question 4.
The flow charts A and B given below represents the inheritance of normal haemoglobin and sickle cell haemoglobin: (MAY-2010)

a) Observe flow chart A and complete the flow chart B.
b) Note down the genotype of a sickel cell anaemia patient and mention the symptom of the disease.
c) Mention the peculiarity of Hb^A Hb^s phenotype.

Answer:
a)

b) Sickle cell Anemia genotype is homozygous for Hb^s (Hb^sHb^s).
Symptoms
SevereAnemia
Oxygen shortage etc.
Haemoglobin becomes sickle shaped.
c) Hb^A Hb^s indicate heterozygous individuals, who are the carrier of sickle cell Anemia, but unaffected ones.

Question 5.
After analyzing’the karyotype of a short statured round headed person with mental retardation, a general physician noticed an addition of autosomal chromosome. (MARCH-2011)
Answer the following questions.
a) Addition or deletion of chromosome generally results in ______
b) What may be the possible syndrome or disorder of the above person should suspected to be?
c) Suggest two / more morphological peculiarities to confirm the chromosome disorder in that person.
Answer:
a) Aneuploidy / Chromosomal disorders/ Chromo-somal abberrations/Chromosomal mutations.
b) Down’s syndrome / Mongolism / Trisomy 21st / 45A + xx / xy.
c) Furrowed tongue, partially opened mouth, Broad palm, Skin fold at the corner of the eye.
Two correct points.

Question 6.
The frequency of occurrence of Royal disease or . haemophilia is high in the pedigree of royal families of Queen Victoria. Which of the following cannot be generally inferred from this? (MARCH-2011)
a) Queen Victoria was not homozygous forthe disease.
b) Many heterozygous females were there in the Royal families.
c) Non-Royal families were not affected with haemophilia.
d) There is less possibility to become a female diseased.
e) Generally a diseased female cannot survive after the first menstruation.
f) Pedigreee analysis is the study of inheritance patterns of traits in human females.
Answer:
‘C’ and ‘f ’ c₁ non royal families were not affected with haemophilia.
f₂ Pedegree analysis is the study of inheritance pattern of traits in human females.

Question 7.
A couple have two daughters. The blood group of husband and wife is ‘O’ (MARCH-2011)
a) What is the possible blood groups of the children should have?
b) Whether any change in blood group will occur if they have two sons instead of daughters.
Substantiate your answer.
Answer:
a) O group
b) No.
There is no sex specificity in blood group alleles / Co-dominance / Homozygous recessive. Not related to sex chromosomes or autosomes /

Question 8.
Complete the table using suitable terms. (MARCH-2012)
Turner’s syndrome (a) ______ Sterile female
(b) __________44A + XXY (c) _________
(d) __________ Trisomy 21 Mental retardation
Answer:
a) 44A + X0
b) Klinefelters Syndrome
c) Sterile male
d) Down’s Syndrom

Question 9.
In pea plant the gene for yellow seed colour is dominant over green and round seed shape is dominant over wrinkled. Write the four types of gametes formed in a heterozygous pea plant with yellow and round seeds. (Yy Rr).
Answer:
YR Yr yR yr

Question 10.
The first child of a couple is affected with phenylketonuria. During the second pregnancy they visited a genetic counsellor and he prepared a pedigree chart of their family. (MARCH-2012)
a) What is pedigree analysis?
b) Draw the symbols for
i) Affected female.
ii) Sex unspecified.
iii) Consanguineous mating.
Answer:
a) It is the study of inheritance of a trait for several generation of a family.
b)

Question 11.
Diagrammatic representation of chromosome map of Drosophila is given below: (MARCH-2012)

Y – Yellow
W – White
M – Miniature
a) Which genes are more linked?
b) Who mapped the chromosome firstly?
c) Tightly linked genes show low recombination. Why?
Answer:
a) y and w
b) Alfred Sturtevant
c) Crossing over rarely takes between genes

Question 12.
Work of a student is given below:  (MAY-2012)

a) From the above give an example for genotype and phenotype.
b) Complete the work’using punnett square and find out the phenotypic ratio in the F2 generation.
Answer:
a) First filial generation Genotype-RrYy,Phenotype- round yellow

Question 13.
Identify the traits from the pedigree chart. Give one example each.  (MAY-2012)

Answer:
a) Autosomal dominant trait
Eg. Muscular dystrophy
b) Autosomal recessive trait
Eg. Sickle cell anaemia

Question 14.
A poultry farm manager was cursing his hens for producting lion share of cocks in its progeny. Hearing this, Kumar – farm attender starts to blame his wife for delivering consecutive girl children. Analyze the situtations scientifically and state whether you agree with kumar.  (MARCH-2013)
Answer:
No, During spermatogenesis two types of gametes are produced of which 50 per cent carry the X- chromosome and the rest 50 per cent has Y- chromosome besides the autosomes. Females produce only one type of ovum with an X- chromosome.
In case the ovum fertilises with a sperm carrying X- chromosome the zygote develops into a female (XX) and with Y-chromosome results into a male offspring. Thus the genetic makeup of the sperm that determines the sex of the child.

Question 15.
In the given pedigree the shaded figures denote individuals expressing a specific trait. (MARCH-2013)

Which of the following is the most probable mode of inheritance of this trait.
Answer:
Principles of inheritance & Variation
A – Simple Mendelian Recessive
B – Co dominant relationship of a single pair of alleles.
C- X – linked recessive transmission
D – X- linked dominant transmission
E – Polygenic inheritance.
X-Linked recessive transmission

Question 16.
“Gopalan argues that if father is of A’ blood group, mother is of ‘B’ blood group. Their children can only be A’ group, B group or AB’ group.” (MARCH-2014)
a) Do you agree with Gopalan’s Argument ?
b) Give reason for your answer.
Answer:
a) No ,All groups are possible including O group
b) 

Question 17.
Identify the syndrome from the genotype given below: (MAY-2014)
1) 44 Autosomes + XXY
2) 44 Autosomes + XO
Answer:
1) Klinefelters syndrome
2) Turners syndrome

Question 18.
The family of Queen Victoria shows a number of haemophilic descendants as she was the carrier of the disease. Name the pattern of inheritance of this royal disease. (MAY-2014)
Answer:
Sex linked inheritance .
The heterozygous female (carrier) for haemophilia may transmit the disease to sons.
(Criss cross inheritance)

Question 19.

a) Identify the syndrome from the diagram, and write the genotype. (MARCH-2015)
b) It occurs in both sexes (male and female)? Write the reason.
Answer:
a) Downs syndrome , 45 A+XX or 45A+XY
b) The cause of this genetic disorder is the presence of an additional copy of the chromosome number 21 (trisomy of 21).

Question 20.
It is evident that, it is the genetic make up of the sperm that determine the sex of the child in human beings. Substantiate. (MARCH-2015)
Answer:
During spermatogenesis among males, two types of gametes are produced. 50% of the total sperm produced carry the X-chromosome and the rest 50 per cent has Y-chromosome besides the autosomes. In case the ovum fertilises with a sperm carrying X- chromosome the zygote develops into a female (XX) and the fertilisation of ovum with Y-chromosome carrying sperm results into a male offspring. Hence the genetic makeup of the sperm that determines the sex of the child.

Question 21.
Diagrammatic representation of the pedigree analysis of the inheritance of sickle cell anaemia is shown below: (MAY-2015)

a) Name the type of inheritance shown in the figure.
b) Write the genotype of A and B.
(Hint: Disease is controlled by a pair of alleles Hb^A & Hb^s)
Represent pedigree analysis of an X-linked recessive inheritance diagrammatically.
Answer:
a) Mendalian inheritance
b) A-Hb^A Hb^s B- Hb^A Hb^s

Question 22.
Observe the inheritance shown in A (MAY-2015)

a) Name the type of inheritance shown in A and B.
b) What is the difference between the two types of inheritance.?
Answer:
a) A- Dominance B-Co dominance
b) In dominance , dominant gene mask the expression of recessive gene and tall character in F₁ progenies but in co dominance both dominant gene express together and shows AB blood group.

Question 23.
Results of a famous experiment is given in the figure. Answer the questions. (MARCH-2016)

a) Identify the experiment.
b) Which property of the DNA is proved by this experiment?
Answer:
a) Semiconservative DNA replication experiment
b) During DNA replication one parent strand is conserved

Question 24.
Which of the following is not a Mendelian disorder? (MARCH-2016)
i) Colourblindess
ii) Down’s syndrome
iii) Haemophilia
iv) Thalassemia
Answer:
ii) Down’s syndrome

Question 25.
Study the following cross and answer the questions. (MARCH-2016)

[Hint: ABO blood group in man is controlled by three alleles I^A, I^B, and i]

a) Write the geno types of Father, Mother and Son.
b) The type of dominance of human blood group inheritance is ________.
Answer:
Father-I_A i or i i Mother-I_B or i i Son-i i

Question 26.
Observe the figures and answer the questions. (MARCH-2016)

a) Identify the syndromes A and B.
b) What is the chromosome numbers in A and B?
Answer:
a) A-KlinefelterSyndrome;
B- Turner’s Syndrome
b) A-47 B-45

Question 27.
a) Complete the flow chart of chromosomal disorder by filling the blank boxes (A and B). (MAY-2016)

b) What is an euploidy?
Answer:
a) A-monosomy of sex chromosome B – Klinefelters syndrome
b) Failure of separation of homologous chromosomes during anaphase I of meosis lead to gain or loss of chromosome, it is called aneupoidy.

Question 28.
Observe the figure below and answer the questions following: (MAY-2016)

a) Identify the figure
b) What shows the shaded symbols used?
Answer:
a) Pedigree analysis or Autosomal dominant trait
b) Individuals with genetic disorder (male and female)

Question 29.
The following table shows the F₂ generation of a dihybrid cross, identify the ‘Phenotype’ with homozygous recessive genotype.(MARCH-2017)
Find out A : B : C : D.

Answer:
B , Genotype A: B:C:D: = 3:1:9:3 OR 9:3:3:1

Question 30.
Which of the following do not have similar sex chromosomes? (Homogametic) (MARCH-2017)
a) Human female
b) Drosophila female
c) Bird female
d) Bird male
Answer:
c) Bird female

Question 31.
Observe the following diagram and answer the questions: (Hint: Steps in making a cross in pea plant) (MAY-2017)

a) Name the process marked as A and write its significance.
b) Diagrammatically represent a monohybrid cross between Tall and dwarf pea plants.
Answer:
a) Removal of anthers from female plants
Significance –It prevents self pollination and fertilization

Question 32.
Observe the diagrammatic representation of the following pedigree analysis and answer the questions (MAY-2017)
a) Describe the type of inheritance shown in the diagram.
b) Distinguish between Mendelian disorder and chromosomal disorder with example.

Answer:
a) Sex linked inheritance
b) Mendelian disorder is determined by mutation in the single gene.
These disorders are transmitted to off springs in the same line as the principles of inheritance.

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 2 Reproductive Health.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 2 Reproductive Health

Question 1.
Diagram shown below is a surgical method used for female sterilization. (MARCH-2010)
a) What is the method shown in diagram?
b) Mention any two Intra uterine devices to prevent conception.
c) What is the surgical method of male sterilization called?

Answer:
a) Tubectomy
b) Any two methods (Cu-T, Cu-7, loop, Multibad-375, Hormone producing progestogent, LNG-20 etc)
c) Vasectomy

Question 2.
Select the Assisted Reproductive Technique that uses an early embryo with upto 8 blastomeres.   (MAY-2010)
a) ZIFT
b) IUT
c) GIFT
d) IUI
Answer:
a) ZIFT

Question 3.
One among the contraceptive method is peculiar. Find the odd one. What is common among others?  (MARCH-2011)
a) Periodic abstinence
b) Coitus interruptus
c) Lactational amenorrhea
d) lUD’s
Answer:
d) lUD’s
Others are natural contraceptives/Natural methods/ Others have more chance of conception / IUD is the barrier method.

Question 4.
The treatment facility advertised on the brochure of a private clinic is shown below.  (MARCH-2011)
a) Can you suggest what type of a clinic it is ?
b) Make a brief note on any three of the treatment procedure.

Answer:
a) Infertility clinic / Fertility treatment clinic / Assisted Reproductive clinic or Hospital.
b) IVF-Invitro Fertilization
ZIFT – Zygote Intra Fallopian Transfer
GIFT – Gamete Intra Fallopian Transfer
IUI – Intra Uterine Insemination.

Question 5.
“STDs present a major health concern in both industralized and developing countries.”  (MARCH-2012)
a) What do you mean by STDs?
b) Name two STDs.
c) Suggest two preventive measures.
Answer:
a) Sexually transmitted diseases
b) Gonorrhoea and Syphilis
c) Avoid sex with unknown partners and use condom during coitus.

Question 6.
Find out the odd one from the following, write the reason.  (MAY-2012)
a) CuT
b) Cu7
c) LNG-20
d) Multiload – 375
Answer:
LNG-20

Question 7.
One couple came to know that they have a girl child during fourth month of pregnancy and they decide to do MTP.  (MAY-2012)
a) What is MTP ?
b) At which stage of pregnancy MTP relatively safe?
c) How will you respond to the decision of female foeticide by the couple?
Answer:
a) Medical termination of pregnancy
b) MTPs are safe during the first trimester, i.e., upto 12 weeks of pregnancy.
c) MTPs must be essential where continuation of the pregnancy could be harmful or even fatal either to the mother or to the foetus.

Question 8.
One of your friend argued that anti-retroviral drugs are effective medicine to treat AIDS.  (MAY-2012)
a) What is your opinion about it?
b) How HIV affect out immunity?
Answer:
a) It prevents the growth and multiplication of viruses
b) HIV enters into helper T-lymphocytes (TH), replicates and produce progeny viruses. The progeny viruses released in the blood attack other helper T-lymphocytes, as result the patient becomes immuno-deficient

Question 9.
Most often HIV infection occur due to conscious behaviour patterns. Do you agree with this statement? Substantiate your answer.  (MARCH-2013)
Answer:
No,
1) blood transfusion
2) During birth of child
Yes,
1) sexual contact
2) Intraveinous injection

Question 10.
Suggest the ART which may be successful in the following conditions. (MARCH-2013)
a) A female cannot produce ovum, but can provide suitable environment for fertilization and further development.
b) Male partner is unable to inseminate the female or has very low sperm count.
c) Fusion of gametes and zygote formation does not occur within the body of the female.
Answer:
a) Transfer of an ovum collected from a donor into the fallopian tube (GIFT – gamete intra fallopian transfer) of another female who cannot produce one, but provide suitable environment for fertilisation and further development
b) Intra cytoplasmic sperm injection (ICSI) Here a sperm is directly injected into the ovum. It is the procedure to form an embryo in the laboratory
c) In vitro fertilisation (IVF—fertilisation outside the body in almost similar conditions as that in the body) followed by embryo transfer (ET).

Question 11.
Prepare a pamphlet for Adolescent children to make them aware of alcohol and drug abuse. (MAY-2013)
Answer:
Education and counseling, moral education, Avoid undue peer pressure .visual publicity through TV, seeking professional and medical help etc.

Question 12.
One of your neighbour is suffering from itching, fluid discharge, slight pain and swelling in genital region. (MARCH-2014)
a) What do you think the disease he is suffering from?
b) What measures are to be taken to prevent such diseases?
Answer:
a) Sexually transmitted disease (STD) Eg-gonor- rhoea, syphilis etc.
b) 1) Avoid unknown sexual partner
2) Use condoms during coitus

Question 13.
Expand the following abbreviations which are commonly used in reproductive health: (MARCH-2014)
a) ART
b) ZIFT
Answer:
a) ART – Assisted reproductive techonology
b) ZIFT – Zygote intra fallopian transfer

Question 14.
______ and _____ are two surgical contraceptive methods in males and females respectively. (MAY-2014)
Answer:
Vasectomy,Tubectomy

Question 15.
Sex of the baby is determined by the father, not by the mother. Substantiate. (MAY-2014)
Answer:
ovum fertilises with a sperm carrying X- chromosome the zygote develops into a female (XX) and the fertilisation of ovum with Y-chromosome carrying sperm results into a male offspring. Hence the genetic make up of the sperm that determines the sex of the child.

Question 16.
Amniocentesis for sex determination is banned in our country? Is this ban necessary? Comment. One use of amniocentesis. (MAY-2014)
Answer:
Yes, Ban on amniocentesis for sex-determination to legally check increasing female foeticides. It is a foetal sex determination test based on the chromosomal pattern in the amniotic fluid surrounding the developing embryo.

Question 17.
Identify the diagram and write how it acts? (MARCH-2015)

Answer:
Copper T (CuT), lUDs increase phagocytosis of sperms within the uterus and the Cu ions released suppress sperm motility and the fertilising capacity of sperms.

Question 18.
Foetal sex can be determined by a test based on the chromosomal pattern from the amniotic fluid.  (MARCH-2015)
a) What is this test?
b) Revealing of sex determination through this test is banned. Is this ban necessary? Comment.
c) Invitro fertilization followed by embryo transfer is known as _____.
Answer:
a) Aminocentesis
b) Yes, Ban on amniocentesis for sex- determination to legally check increasing female foeticides.
c) Test tube baby programme

Question 19.
If proper care and attention is not given by adults, adolescents may become addicted to drugs/ alcohol.” What is your opinion about this statement? Substantiate your answer.  (MAY-2015)
Answer:
Adolescence is a bridge linking childhood and adulthood. It is the very vulnerable phase of mental and psychological development of an individual. Repeated use of drugs, the tolerance level of the receptors present in our body increases. Consequently the receptors respond only to higher doses of drugs or alcohol leading to greater intake and addiction.

Question 20.
Some techniques commonly used for infertility treatment are given below. Read them carefully and answer the questions.  (MAY-2015)
ZIFI , GJFF, ICSI, IUI, IVF
a) Which of the above technique is used forthe collection of sperm from the husband or a healthy donor and artificially introduced into the vagina or uterus of the female?
b) Distinguish between ZIFT and GIFT.
c) Write the common term used to denote ‘ tech-niques given above
Answer:
a) IUI
b) ZIFT- Ova from the wife/donor (female) and sperms from the husband/donor (male) are collected and are induced to form zygote under simulated conditions in the laboratory. The zygote or early embryos (with upto 8 blastomeres) are transferred into the fallopian tube
b) GIFT-Transferof an ovum collected from a donor into the fallopian tube of another female who cannot produce it ,but can provide suitable environment for fertilisation
c) Assisted reproductive technologies (ART)

Question 21.
Categorise the given birth control methods into three groups with proper heads.  (MARCH-2016)
Cervical caps, Vasectomy, Cu T, Tubectomy, Diaphragms, Condom, Lippes Loop
Answer:
lUDs- Cu T, LiPPes loop
Barrier method- Diaphrams, Condoms Cervical caps, surgical method – Vasectomy, Tubectomy,

Question 22.
Diagnostic report of two couples having infertility problems are given below:  (MAY-2016)
1) The woman cannot produce ovum.
2) The man has very low sperm count in semen. Suggest a suitable Assisted Reproductive Technologies (ART) for each problem in expanded form
Answer:
1) GIFT -Gamete intra fallopian transfer
2) lUI-Intra uterine insemination/AI-Artificial insemination.

Question 23.
Which of the following pairs of STDs is completely curable?  (MARCH-2017)
1) HIV, Hepatitis-B
2) Hepatitis-B, Gonorrhoea
3) Syphilis, Gonorrhoea
4) Chlamydomonas, genital-herpes
Answer:
3) syphilis, gonorrohea

Question 24.
a) What is ART?  (MARCH-2017)
b) Categorize the following ARTs based on their applications in male sterility and female sterility:
GIFT, Al
Answer:
a) In the case of infertility, the couples could be assisted to have children through certain special techniques commonly known as assisted reproductive technologies (ART),
b) GIFT-Female,
Al – Male

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 1 Human Reproduction.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 1 Human Reproduction

Question 1.
Given below is the diagrammataic representation of human blastocyst. Observe the diagram and answer the following questions: (MARCH-2010)

a) Identify A and B
b) Write the functions of A and B.
Answer:
a) A – Inner cell mass, B – Trophoblast
b) A – Differentiate into embryo germ layers/gastrula B – Attachment to endometrium / form different embryonic membranes/ placenta formation/ nutritional supply.

Question 2.
When the urine sample of a lady is tested, presence of Human Chorionic Gonadotropin (HCG) is detected. (MARCH-2010)
a) What does the presence of HCG indicate?
b) Which is the source of HCG?
Answer:
a) Pregnancy
b) Placenta

Question 3.
The graph shown below shows the levels of LH and FSH at various stages of menstrual cycle. (MAY-2010)

a) Name the source of LH and FSH.
b) The level of LH is maximum during the middle day of the cycle. Mention its effect.
c) Note the function of LH in males.
Answer:
a) Pituitary gland
b) Helps for ovulation
c) Stimulates the synthesis of horrnones (androgens)

Question 4.

The above graph shows the level of ovarian hormones in a normally menstruacing woman during the follicular phase. (MARCH-2011)
a) Name ‘a’ and ‘b’
b) Mention the role of pituitary hormones in maintaining this condition.
c) Reconstruct the graph for Luteal phase.
Answer:
a) i) Estrogens
ii) Progesterone
b) FSH / Follicle stimulating Hormone, LH / Luteinizing Hormone
OR
Gonadotropins
One function each of FSH and LH.
c)

Question 5.
Some stages of the embryonic development are given below. Observe these diagrams and answer the questions. (MAY-2011)

a) What is A & B?
b) Name thetwo types of cells found in the blastocyst.
c) Which layer of blastocyst is attached to the endometrium? And name that process.
Answer:
a) A – Blastomere B – Morula
b) Trophoblast and inner cell mass
c) Trophoblast, Implantation

Question 6.
Observe the diagram provided (Do not copy the picture) (MARCH-2012)

a) Label A and B
b) On which day of menstrual cycle Graafian follicle rupture.
c) Name the process induces the rupture of Graafian follicle.
d) Write the name and function of the structure forming inside the ovary after the rupture of Graafian follicle.
Answer:
a) A – Primary follicle B – Tertiary follicle
b) 14th day
c) The rupture of Graafian follicle and the release of ovum is called ovulation.
d) The corpus luteum secretes large amounts of progesterone which helps in the maintenance of the endometrium.

Question 7.
The following statements compares the process of oogenesis and spermatogenesis. Which one is not true?  (MAY-2012)
a) Production of ovum ceases at certain age, but sperm production continues even in old men.
b) Oogenesis begins in the embryonic stages, but spermatogenesis starts at the onset of puberty.
c) Meiotic arrest occurs both in Oogenesis and spermatogenesis.
d) Polar bodies are formed in oogenesis.
Answer:
a) Replication
b) Transcription
c) Translation
d) Reverse transcription

Question 8.
The diagram represents a process of gametogenesis. Closely observe it and answer the following  (MARCH-2013)

Is it spermatogenesis or Oogenesis?
What does the smaller shaded circle represent? Write down two significance of production of the same.
Answer:
a) oogenesis
b) polar bodies
c) Retention of cytoplasm in ovum Maintaining one functional haploid ovum

Question 9.
Though one ovum is produced from a primary oocyte it can result into a male or female child after fertilization. But in the case of spermatocyte though 4 sperms are produced only two of them can result to a female child after fertilization”. Justify.  (MARCH-2013)
Answer:
Two types of sperms are produced one with x chromosomes and other withy chromosome. Sperm with x chromosome after fertilization results in the formation of female baby

Question 10.
Sterilization and IUDS are effective birth control measures, but lactational amenorrhea may not be so effective.  (MAY-2013)
a) How the sterilization procedure of males differ from that of females in preventing pregnancy?
b) Which part of the female reproductive organ is utilized for the IUD procedure? How this procedure prevents pregnancy?
c) Why the lactational amenorrhea is not so effective?
Answer:
a) In males the sterilization method is called vasectomy but in females it is called Tubectomy
b) uterus, lUDs suppresses sperm motility and fertilizing capacity of sperm or they make uterus unsuitable for implantation.
c) During intense lactation, menstrual cycle does not occur. Therefore the chance of conception is almost nil. But the method is effective only upto six months following delivery

Question 11.
Observe the diagram, and answer the questions: (MARCH-2013)
a) Identify A and B.
b) What is the function of C ?
c) In which of the marked part reduction division takes place? What is the significance of it?

Answer:
a) A – Spermatozoa, B-Primary spermatocyte
b) Sertoli cells provide nutrition to the germ cells.
c) Primary spermatocyte, chromosome number reduced to half

Question 12.
Diagram of a mammalian sperm’is given. Label the parts marked. (MAY-2014)

Answer:
A – Acrosome
B – Nucleus containing chromosomal material

Question 13.
Schematic representation of gametogenesis is given below. Identify A. Write one difference between A& B. (MARCH-2015)

Answer:
A) Spermatogenesis – It results 4 spermatozoa
B) Oogenesis – It results one ovum and polar body

Question 14.
1) In which part of the human reproductive system the following events occur? (MARCH-2015)
a) Fertilisation
b) Implantation
2) Diagram of a human biastocyst is given below. Identify A & B.

Answer:
a) ampullary-isthmicjunction
b) Endometrium of the uterus
A – inner cell mass
B – trophoblast

Question 15.
Choose the odd one from the following and write the common feature of others; (MAY-2015)
a) Estrogen
b) Androgen
c) Relaxin
d) Progesterone
Answer:
Androgen.
Others are ovarian hormones.

Question 16.
Complete the flow chart showing spermatogenesis by filling A and B and answer the questions: (MAY-2015)

a) What is the chromosome number of primary spermatocyte
b) What is the significance of reduction division in spermatocyte?
Answer:
A- Spermatogonia
B- Spermatids
a) Primary spermatocyte-Diploid number, in man it is 23 pair, spermatids-haploid number, in man it is 23
b) Reduction division helps to reduce chromosome number as half in gametes (haploid).
It helps keep chromosome number species as constant for many generations.

Question 17.
Match the columns A and B: (MARCH-2016)

Answer:

Question 18.
The process of fusion of a sperm with ovum is called _______. (MAY-2016)
Answer:
Fertilisation

Question 19.
Match columns A and B.  (MAY-2016)

Answer:

Question 20.
LH and FSH are gonadotrophins. Distinguish their roles in males and females.  (MARCH-2017)
Answer:
LH acts at the Leydig cells and stimulates synthesis and secretion of androgens.
Androgens stimulate the process of spermato-genesis.
FSH acts on the Sertoli cells and stimulates secretion of some factors which help in the process of spermiogenesis.
Female Rapid secretion of LH leading to rupture of Graafian follicle and release ovum (ovulation). FSHhelpsinthe growth and development of ovarian follicle.

Question 21.
Human female possess 44 + XX chromosome number. The chromosome number of secondary oocyte is  (MAY-2017)
a) 44 + X
b) 22 + X
c) 44 +XX
d) 22 +XX
Answer:
b) 22 + X

Question 22.
Observe the diagram and answer the questions:  (MAY-2017)

a) Identify A and B
b) Write the function of B.
Answer:
a) A – peri vitelline space
B- zona pellucida
b) Prevent the entry of further sperms after fertilization