‘Grafting is a common method of obtaining a superior plant from two different plants’. Explain.

1. List in tabular form two differences between binary fission and multiple fission.
2. What happens when a mature Spirogyra filament attains considerable length.

Name the parts A, B and C shown in the diagram a d write their functions.

Write two examples each of sexually transmitted diseases caused by (i) virus, (ii) bacteria. Explain how the transmission of such diseases be prevented?

What is contraception? Name any two methods. How does the use of these methods have a direct effect on the health and prosperity of a family? State any three points.

What does HIV stand for? Is AIDS an infectious disease? List any four modes of spreading AlDS.

What happens when

1. Planaria gets cut into two pieces?
2. A mature spirogyra filament attains considerable length?
3. On maturation sporangia burst?

What is meant by pollination? Name and differentiate between the two modes of pollination in flowering plants.

What is a seed? What are the parts of a seed? Explain with the help of a labelled diagram.

1. Write the names of those parts of a flower which serve the same function as the following do in the animals:

1. Testis.
2. Sperm.
3. Ovary.
4. Egg.

2. State the function of flowers in the flowering plants.