Download Biology 50 QP - Kendriya Vidyalaya INS Valsura

KENDRIYA VIDYALAYA INS VALSURA
Fifty questions (Dec. 2015)
CLASS: XII
SUB: BIOLOGY
1. What is pollen-pistil interaction and how is it mediated?
2. Why do normal red blood cells become elongated sickle shaped structures in a person suffering
from sickle cell anaemia?
3. What is an autoimmune disease? give an example.
4. Write the two components of the first artificial recombinant DNA molecule constructed by Cohen
and Boyer.
5. Name the host cells in which micro-injection technique is used to introduce an alien DNA.
6. Write the name of the enzymes that are used for isolation of DNA from bacterial and fungal cells
respectively for Recombinant DNA technology.
7. State the purpose of signing the Montreal Protocol.
8. In spite of being non-polluting, why are there great apprehensions in using nuclear energy for
generating electricity?
9. Name the part of the flower which the tassels of the corn-cob represent.
10. Mention any two contrasting traits with respect to seeds in pea plant that were studied by Mendel.
11. Why is secondary immune response more intense than the primary immune response in humans?
12. Why is it not possible for an alien DNA to become part of a chromosome anywhere along its
length and replicate normally?
13. State the role of C peptide in human insulin.
14. Name the enzymes that are used for the isolation of DNA from bacterial and fungal cells
for recombinant DNA technology.
15. State Gause’s Competitive Exclusion principle.
16. Name the type of association that the genus Glomus exhibits with higher plants.
17. Write the name of the organism that is referred to as the ‘Terror of Bengal’.
18. What are ‘true breeding lines’ that are used to study inheritance pattern of traits in plants?
19. Name any two types of cells which act as ‘Cellular Barriers’ to provide Innate Immunity
in humans.
20. Mention the type of host cells suitable for the gene guns to introduce an alien DNA.
21. How is ‘stratification’ represented in a forest ecosystem?
22. Give an example of an organism that enters ‘diapause’ and why.
23. Identify ‘a’ and ‘b’ in the figure given below representing proportionate number of major vertebrate
taxa.
24. State the cause of accelerated eutrophication.
25. How many pollen grains and ovules are likely to be formed in the anther and the ovary
of an angiosperm bearing 25 microspore mother cells and 25 megaspore mother cells respectively?
26. How does the flow of genetic information in HIV deviate from the ‘Central dogma’ proposed by
Francis Crick?
27. What did Louis Pasteur’s experiment on ‘killed yeast’ demonstrate? Name the theory that got
disproved on the basis of his experiment.
28. State the functions of mast cells in allergy response.
29. How does an alien DNA gain entry into a plant cell by ‘biolistics’ method?
30. State the purpose for which the Indian Government has set up GEAC.
31. Name a ‘photoperiod’ dependent process, one each in plants and in animals.
32. Mention the effect of UV rays on DNA and proteins in living organisms.
33. Name an organism where cell division in itself is a mode of reproduction.
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KENDRIYA VIDYALAYA INS VALSURA
Fifty questions (Dec. 2015)
CLASS: XII
SUB: BIOLOGY
34. When does a human body elicit an anamenstic response?
35. Name any two diseases the ‘Himgiri’ variety of wheat is resistant to.
36. State the role of transposons in silencing of mRNA in eukaryotic cells.
37. Why are green algae not likely to be found in the deepest strata of the ocean?
38. State what does ‘standing crop’ of a trophic level represent.
39. Why is the use of unleaded petrol recommended for motor vehicles equipped with catalytic
converters?
40. Name the type of biodiversity represented by the following:
(i) 1000 varieties of mangoes in India.
(ii) Variations in terms of potency and concentration of reserpine in Rauwolfia vomitoria growing in
different regions of Himalayas.
41. An anther with malfunctioning tapetum often fails to produce viable male gametophytes. Give any
one reason.
42. Why sharing of injection needles between two individuals is not recommended?
43. Name the enzyme and state its property that is responsible for continuous and discontinuous
replication of the two strands of a DNA molecule.
44. Identity the examples of convergent evolution from the following:
(i) Flippers of penguins and dolphins
(ii) Eyes of octopus and mammals
(iii) Vertebrate brains
45. Write the importance of MOET.
46. Why is the enzyme cellulase needed for isolating genetic material from plant cells and not from
the animal cells?.
47. Name the type of biodiversity represented by the following:
(i) 50,000 different strains of rice in India
(ii) Estuaries and alpine meadows in India.
48. Write the equation that helps in deriving the net primary productivity of an ecosystem.
49. How is it possible in Oxalis and Viola plants to produce assured seed-sets even in the absence of
pollinators?
50. Why do pollen grains of some flowers trigger ‘sneezing’ in some people?
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KENDRIYA VIDYALAYA INS VALSURA
Fifty questions (Dec. 2015)
CLASS: XII
SUB: BIOLOGY
ANSWER KEY
1. The ability of the pistil to recognise the pollen followed by its acceptance or rejection. It is mediated
by chemical components of pollen interacting with those of pistil.
2. Due to point mutation, glutamic acid (Glu) is replaced by valine (Val) at the sixth position of β-globin
chain of haemoglobin molecule. Under oxygen stress erythrocytes lose their circular shape and
undergo polymerisation to become sickle-shaped.
3. It is an abnormal immune response in which the immune system of the body starts rejecting its own
body cells or ‘self ’ cells and molecules. For example, rheumatoid arthritis.
4. The two components were—antibiotic resistance gene and plasmid vector of Salmonella
typhimurium.
5. Animal cells.
6. Bacterial cell is treated with enzyme lysozyme.
Fungal cell is treated with chitinase.
7. Montreal Protocol, was signed at Montreal, in 1987 to curb the emission of ozone depleting
substances.
8. There are great apprehensions in using nuclear energy because of accidental leakages and finding
ways for safe disposal of radioactive waste.
9. Style and stigma.
10. Round/Wrinkled, Yellow/Green
11. This is because of presence of antibodies developed during primary.
12. Alien DNA must be linked to ori or origin of replication site to start replication.
13. C-peptide (extra stretch of polypeptide) makes the insulin inactive.
14. Bacteria: lysozyme; fungi: chitinase.
15. Gause’s competitive Exclusion Principle states that two closely related species competing
for same resources, cannot coexist indefinitely (the inferior will be eliminated).
16. Symbiosis/Mycorrhizae/Mutualism.
17. Water hyacinth (Eicchornia crassipes).
18. True breeding lines are plants which have undergone continuous self-pollination for
several generations. These are homozygous for traits.
19. Polymorpho-nuclear Leukocytes/Neutrophils/Monocyte, Natural Killer (type of
lymphocyte), macrophages.
20. Plant cells
21. Stratification in the vertical distribution of species at different bonds. Trees occupy vertical strata,
shrubs the second layer and herbs/ grasses occupy the bottom layers.
22. Many species of Zooplankton unfavourable conditions which delay overall development.
23. (a) Mammals
(b) Amphibians
24. Pollutants from human activities, effluents from industries effluents from home, sewage and
agricultural (chemical wastes radically accelerate the aging process.
25. 100 pollen grains and 100 ovules.
26. In HIV single stranded RNA is converted to double stranded DNA.
27. Louis Pasteur demonstrated that life comes only from pre-existing life. The theory of
spontaneous generation was disproved on the basis of his experiment.
28. Mast cells release chemicals like histamine and serotonin in allergic response.
29. In biolistics method cells are bombarded with high velocity micro-particles of gold or
tungsten coated with DNA.
30. GEAC was set up to make decisions regarding the validity of GM research and the safety of
introducing GM-organisms for public services.
31. In plants, flowering and in animals, migration/foraging are photoperiod dependent
processes.
32. The high energy of UV rays breaks the chemical bonds within DNA and protein molecules.
33. Protists/Monerans/Amoeba/Paramecium.
34. At the time of secondary response.
35. Leaf and stripe rust; Hill bunt
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KENDRIYA VIDYALAYA INS VALSURA
Fifty questions (Dec. 2015)
CLASS: XII
SUB: BIOLOGY
36. Transposons or mobile genetic elements in viruses are the sources of the complementary
dsRNA, which in turn bind to specific mRNA and cause RNA interference of the parasite.
37. The wavelength of light at the deepest strata is unsuitable for growth of green algae.
38. Standing crop represents the mass of living material (biomass) at a particular time.
39. Lead in the petrol inactivates the catalyst in the converter, which catalyses the conversion
of unburnt hydrocarbons into CO2 and H2O.
40. (i) Genetic diversity
(ii) Genetic diversity
41. A malfunctioning tapetum does not provide enough nourishment to the developing
male gametophytes and thus fail to produce viable male gametophytes.
42. Sharing of needles can transmit diseases like HIV, AIDS, Hepatitis B or C from infected
to non-infected individuals.
43. DNA dependent DNA polymerase. It catalyses polymerisation in 5’ → 3’ direction only.
44. (i) Flippers of penguins and dolphins
(ii) Eyes of octopus and mammals
45. MOET is used to increase the herd size in a short time/improves the chances of
production of hybrids.
46. The enzyme cellulase breaks down cellulose which is present in cell walls of plants but
absent in animal cells.
47. (i) Genetic diversity (ii) Ecological diversity
48. GPP - R = NPP
49. By presence of cleistogamous flowers.
50. They result in an allergic reaction.
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