1. What is the importance of DNA copying in reproduction?
2. How will an organism be benefited if it reproduces through spores?
3. Why is DNA copying an essential part of the process of reproduction?
4. What is the role of the seminal vesicles and the prostate gland?
5. What are the different methods of contraception?
6. What could be the reasons for adopting contraceptive methods?
7. Draw a labelled diagram of the longitudinal section of a flower.
8. What are the functions performed by the testis in human beings?
9. How does the creation of variations in a species promote survival?
10. How do Mendel’s experiments show that traits are inherited independently?
11. How is the sex of the child determined in human beings?
12. What are the different ways in which individuals with a particular trait may increase in a population?
13. What factors could lead to the rise of a new species?
14. What are fossils? What do they tell us about the process of evolution?
15. In evolutionary terms, can we say which among bacteria, spiders, fish and chimpanzees have a ‘better’ body design? Why or why not?
16. Explain the importance of fossils in deciding evolutionary relationships.
17. How is the equal genetic contribution of male and female parents ensured in the progeny?
18. What evidence do we have for the origin of life from inanimate matter?
19. Outline a project which aims to find the dominant coat colour in dogs.
20. The radius of curvature of a spherical mirror is 20 cm. What is its focal length?
21. Why do we prefer a convex mirror as a rear-view mirror in vehicles?
22. A convex mirror used for rear-view on an automobile has a radius of curvature of 3.00 m. If a bus is located at 5.00 m from this mirror, find the position, nature and size of the image.
23. A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located?
24. Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 108 m s-1.
25. A concave lens has focal length of 15 cm. At what distance should the object from the lens be placed so that it forms an image at 10 cm from the lens? Also, find the magnification produced by the lens.
26. A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.
27. Find the power of a concave lens of focal length 2 m.
28. One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.
29. A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
30. What is the phenomenon responsible for the blue colour of sky?
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