(Model Paper) Download 12th Class Model Paper ( BIOLOGY )

SECTION A (Zoology) -- Max. Marks: 35 Time 1:30 hrs

Section A
Long Answer Type Questions :

1. Reproduction generally involves two parents. Does it occur uniparently. How?
OR
Assisted reproductive techniques bring hope to infertile couples. Explain How.   5Marks

2. Describe Darwins theory of Natural Selection.
OR
Sex is generally determined by chromosomes of an organism .Does environment also determines sex. Illustrate with examples. 5 Marks

Section B
Short Answer Type Questions.
 
3. What changes occur in the uterus of a human female if the ovum does not receive a sperm? 3 Marks

4. What phenotypic symptoms are produced in an individual due to trisomy of 21st chromosome?  3 Marks

5. Match the entries under section A with the choice given under B and C. 3Marks

6. How Genetic engineering helps in producing pest resistant crops? 3 Marks

Section C
Short Answer Type Questions.

7. Draw a labeled sketch of human sperm? 2 Marks

8. Mention two differences between analogous and homologous organs. 2 Marks

9. Mention two applications of cloning. 2 Marks

10. How does DNA fingerprinting helps in detecting a criminal. 2 Marks

Section (D)
Objective Type Questions:

11. Explain ZIFT. 1 Mark

12. Write the scientific name of Silk moth. 1 Mark

13. Name the antibody present in Colostrum. 1 Mark

14. Human genome is said to have approximately --------------base pairs. 1Mark

15. Give one example of point mutation. 1 Mark

SECTION A (Botany) -- Max. Marks: 35 Time 1:30 hrs

SECTION A
Long Answer Type Questions:

1. How does dominance differ from incomplete dominance? Illustrate with suitable example.
OR
Hershey and Chase conducted an experiment on T₂ Phage using radioisotopes. What were there observations and conclusions?  5 Marks

2. Define an ecosystem. Write an account of energy flow in an ecosystem.
OR
Major pollutants of air are CO₂, SO₂ and NO₂.What are their sources and harmful effects on human beings and plants?5 Marks

SECTION B
Short Answer Type Questions:

3. Vegetative propagation does not lead to variations. Why? 3 Marks

4. What are GM crops? Give two disadvantages of GM crops? 3Marks

5. Biofertilizers are better than Chemical fertilizers. Justify? 3 Marks

6. What is ecological succession? Distinguish between primary and secondary succession. 3 Marks

SECTION C
Short Answer Type Questions:

7. Why cross pollination cannot occur in cleistogamous flowers. 2 Marks

8. What do you mean by degeneracy of genetic code? 2Marks

9. How many phosphorus atoms are there in a DNA double helix having 10,000base pairs? 2 Marks

10. An orchid plant grows on the branch of a mango tree. Give the interaction between the two. 2 Marks

SECTION D
Objective Type Questions:

11. Define apomixis? 1 Marks

12. How many cells are there in a typical angiospermic embryo sac? 1 Marks

13. Define totepotency? 1Marks

14. Which type of ecological interaction is represented in lichens? 1Marks

15. What are schiophytes? 1Marks

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