Describe the following :
Chiasmata.
Draw a diagram to illustrate your answer.

Describe the following : Bivalent. Draw a diagram to illustrate your answer.

Describe the following : Synapis. Draw a diagram to illustrate your answer.

What is atmospheric refraction ? Use this phenomenon to explain the following natural events : (i) Twinkling of stars (ii) Advanced sunrise and delayed sunset. Draw diagram to illustrate your answer.

Draw a labelled diagram to illustrate budding in Hydra.