1. The bone that makes possible rotation of the neck is

2. The life span of human erythrocytes is approximately

3. A ‘clinical death' takes place when

4. Consider the following statements:
1. Cross bridges can cause muscle contraction.
2. They are able to oscillate back and forth and hook up with active sites on actin filaments
3. The bridges enable the thin filaments to pull the thick filaments by a kind of back and forth movement.
4. A single bridge thus hooks onto an active site, pulls the thin filaments a short distance, then releases it and again hooks on the next active site.
Which of the above statements are correct?

5. Aves are

6. Lichen is considered to be a symbiotic association of two living organisms. Which organisms are involved in it?

7. When white -flowered plant were crossed with pure red - flowered plants, the progeny were -

8. DNA nucleotides are attached by

9. Just as the division of cytoplasm is called cytokinesis, the division of nucleus is called

10. Which of the following are mostly woody trees, always perennials and never herbs or annuals?

11. DNA molecules are composed of deoxyribonucleotides of

12. When we eat cauliflower we consume

13. AIDS is caused by the Human Immunodeficiency Virus (HIV) The transmission of HIV infection generally occurs through.

14. Plants absorb dissolved nitrates from soil and convert them into

15. Monocot root differs from dicot root in having

16. The alimentary canal is usually longer in

17. The RNA molecules from a single strand of ribonucleotides of

18. The H-disk in the skeletal muscle fibre is due to

19. The segment of a myofibril that is called a sarcomere runs from

20. Mango contains vitamins

21. The human cell contains

22. Human urine as compared to human blood is

23. The digestive and respiratory passages cross in the

24. Which of the following animals have flippers?

25. Human blood contains _____________ percentage of plasma.