Explain the nature and main reasons (in short) of (a) Haemophila (b) Colourblindness (c) Phenylketonurea

Explain the main reasons for the migration of males and females separately in India.

Explain with reason the nature of emitted particle by:

Explain why carbon forms compounds mainly by covalent bond. Explain in brief two main reasons for carbon forming a large number of compounds. Why does carbon form strong bonds with most other elements ?

Explain the formation of (B), (C ) and (D) in the given reaction: