The cell division involved in gamete formation is not of the same type in different organisms.  Justify.

2

(a)

Name the units of vegetative propagation in water hyacinth.  Explain giving reasons why it has become the most invasive aquatic weed.

2

(a)

Mention the life span of:
(a) Crocodile     (b) Crow    
(c) parrot and     (d) butterfly.

2

(a)

What are
(a) continuous breeders and
(b) seasonal breeders?

2

(a)

What are pre-fertilisation events? Name the two main pre-fertilisation events.

2

(a)

In general, the male gametes are motile while the female gametes are stationary.  Mention two types of exceptions to this, with an example for each.

2

(a)

List three strategies that a bisexual chasmogamous flower can evolve to prevent self pollination (autogamy).

2

(a)

The number of taxa exhibiting asexual reproduction is drastically reduced in the higher plants (angiosperms) and higher animals (vertebrates) as compared with lower groups of plants and animals. Analyse the possible reasons for this situation.

2

(a)

Differentiate binary fission and multiple fission.

2

(a)

How does gamete transfer take place in crosspollinating plants?

2

(a)

How do gemmules and gemma cup differ from each other?

2

(a)

Ram is a person of age 42 years old living in a village of Assam. His house is surrounded by a number of bamboo trees but he could not see any flower on them until now. What can be the explanation of his observation? How does bamboo reproduce?

2

(a)