Question

A pollen grain in angiosperm at the time of dehiscence from an anther could be 2 - celled or 3 - celled. Explain. How are the cells placed within the pollen grain when shed at a 2 - celled stage? [2]

Answer 1

A two celled pollen grain contains a generative and a vegetative cell [0.5]. In three celled stage one vegetative cell and two male gametes are present [0.5].
The vegetative cell is bigger, has abundant food reserve and a large irregularly shaped nucleus [0.5]. The generative cell is small and floats in the cytoplasm of the vegetative cell. It is spindle shaped with dense cytoplasm and a nucleus. [0.5]