Sample Paper – 2008
Class – XII
Subject – Biology
General Instructions:
1. All questions are compulsory.
2. This question paper consists of four Sections A, B, C and D. Section -A contains
8 questions of 1 mark each, Section -B is of 10 questions of 2 marks each,
Section -C has 9 questions of 3 marks each and Section D is of 3 questions of 5 marks each.
3. There is no overall choice .However, an internal choice has been provided
in one question of 2 marks, one question of 3 marks and all the three questions of
5 marks. Attempt only one of the choices in such questions.
4. Wherever necessary, the diagrams drawn should be neat and properly labelled.
SECTION A
1. What is the Ploidy of PEN ? [1]
2. A human zygote has XXY sex chromosomes along with 22 pairs of autosomes
What sex will the individual be? [1]
3. Expand FOAM. What is its significance? [1]
4. Which enzyme is known as ‘molecular scissors’? [1]
5. Name the Ecological pyramid that can be inverted in Tree ecosystem. [1]
6. Explain the term emasculation. When and why does a plant breeder employ [1]
this technique
7. Why is cow dung used in generation of Biogas? [1]
8. Name two animals each that are (i)Oviparous (ii) Viviparous. [1]
SECTION B
9. What are sacred groves ? What is their role in Biodiversity conservation? [2]
10. Mention the advantages of selecting Pea plant for experiment by Mendel. [2]
OR
Why does Mendel’s work gone unnoticed?
11. What measures would you take to prevent water borne disease? [2]
12. What are the disadvantages of human use of Insulin from other animal sources?[2]
13. Name the diseases diagnosed by (a)WIDAL test (b)ELISA test [2]
14. What is Biological Magnification ? [2]
15. Differentiate between Geitonogamy and Allogamy. [2]
16. If the sequence of coding strand in a transcription unit is written as follows : [2]
5’- ATGCATGCATGCATGCATGC-3’
Write the sequence of mRNA
17. Name the technique used for separation of DNA fragments.What is its principle? [2]
18. Define the term Adolescence. How does Peer pressure effect the personality of child? [2]
SECTION C
19 What is meant by Homologous organs? Give an example [3]
20 Differentiate between Menarche and Menopause. [3]
21 What do the differently written terms ‘Cry’ and ‘cry’ represent?
22 Bring out differences between Carbon and Phosphorus cycle of ecosystem.[3]
23 What are the three critical research areas of Biotechnology? [3]
24 What is Apiculture ? How is it important for our lives? [3]
OR
How are microbes helpful in Sewage Treatment?
25 Three Codons on mRNA are not recognized by t RNA. What are they ? What is the general term used for them? What is their role in protein synthesis? [3]
26 Why is the length of a food chain in an ecosystem generally limited to 3-4 trophic levels? [3]
27 A colour blind man marries a woman with normal vision ,whose father was colour blind .Work out a cross to show the genotype of couple and their prospective sons. [3]
SECTION D
28. Who demonstrated the semi-conservative replication of DNA? Explain the procedure indetail.
OR
Describe the Fredrick Griffth’s experiment to prove that DNA is the basic genetic material. [5]
29. What are Algal blooms ? How are they formed ? Give two harmful effects of formation of algal blooms in a water body.
OR
What is Global warming ? give its harmful effects . List strategies of reducing global warming. [5]
30. Trace the development of Megaspore mother cell of Flower in mature ovule with the help of labeled diagram.
OR
Write the function of :
(a) Corpus luteum(b) Endometrium(c) Acrosome(d) Sperm tail(e) Fimbriae [5]
