How do pollen grains affect the life of human beings?

How Is sex determined in human beings?

With the reference to the following figure of stages of a microspore maturing into a pollen grain, answer the question. How many meiotic divisons occurs in the formation of two male gametes ?

Why do pollen grains of some flowers trigger sneezing in some people?

Study of pollen grains is called

Name the greenhouse gases. How do they affect the life on earth? Discuss the measures to control greenhouse effect.

With the reference to the following figure of stages of a microspore maturing into a pollen grain, answer the question. How many mitotic divison takeplace to form two male gametes ?

How does the pollen grains of Vallisneria protect themselves?

How is oxygen and CO_2 Transported in human beings?