Gametes of threatened species can be preserved in a viable and fertile condition for a long time'
Identify the preservation technique used?

Gametes of threatened species can be preserved in a viable and fertile condition for a long time' Why is it considered as an Ex-situ conservation approach?

A student is doing an experiment in the laboratory using sodium. Suddenly, a piece of sodium falls into liquid ammonia. (a) What changes can you observe in liquid ammonia? (b) What is the reason for the change? (c) If the solution is kept for a long time it is changed into bronze colour. Why?

Nicotiana sylvestris flowers only during long days and N.tobacum flowers only during short days. If raised in the laboratory under different photoperiods. they can be induced to flower at the same time and can be cross fenjlized to produce self-fertile offspring. What is the best reason for considering N. sylvestfis and N. tobocum to be separate species?