What is an organic evolution? It cannot be equated with progress. Explain with the help of a suitable example.

What constitutes a female reproductive part in a flower?

Which is the most commonly used method of birth control.

Explain why, more complex multicellular organisms cannot give rise to new organisms through regeneration.

What is regeneration? Give one example of an organism that shows this process and one organism that does not. Why does regeneration not occur in the latter?

Explain how, new Bryophyllum plants can be produced from the leaves of the old plant ? Illustrate your answer with the help of a labelled diagram.

1. List two reasons for the appearance of variations among the progeny formed by sexual reproduction.
2.  

1. Name the part marked ‘A' in the diagram.
2. How does ‘A' reaches part ‘B'?
3. State the importance of the part ‘C'.
4. What happens to the part marked ‘D' after fertilisation is over?

From the internet, gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions.

1. Do larger organisms have more number of chromosomes/ cells?
2. Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes?
3. More the number of chromosomes/ cells greater is the DNA content. Justify.

Explain the meaning of sexually transmitted diseases (STDs). Give two examples of STDs each, caused due to,

1. Bacterial infection.
2. Viral infection. State in brief how the spread of such diseases may be prevented.

(i) Explain the different methods of contraception
(ii) What is menstrual cycle?