Question

Pollen sacs are present in
A)Pollen tube
B)Pollen grain
C)Anther
D)Ovule

Answer 1

The pollen sac is the structure in which pollen is formed in seed plants. The wall of the pollen sac contains a number of archesporial cells that are further from microspore mother cells (microsporocytes).

Complete answer:
There are normally four pollen sacs in each anther in angiosperm; they contain mother cells of the microspore. On the microsporophylls which make up the male cone, variable numbers of pollen sacs are borne in gymnosperms.

A normal bithecous or dithecous anther is composed of two anther lobes, which are connected by a strip of sterile portion called connective. Four elongated cavities, or pollen sacs (microsporangia) in which pollen grains are formed, contain two anther lobes.

From the diploid microspore mother cells in the pollen sacs of anthers, pollen grains grow. Pollen grain is usually a haploid, unicellular body with a single nucleus. Pollen grains are typically spherical measuring between 25-30 micrometers in diameter. There may be spines, ridges or furrows on the outer surface of microspores that may vary in other ways in different species.

Before it leaves the pollen-sac, microspore germination begins. Anything reflecting prothallial growth has been observed in very few instances; a small cell (the antheridial or generative cell) is normally cut off, leaving a larger tube cell.
Such mother-cells are either segregated from each other and float in the granular fluid that fills the pollen-sac cavity, or are not so isolated.

Hence, the correct answer is option (C)

Note: A division takes place in the pollen grain into a vegetative cell or cells from which the tube is produced and a generative cell before leaving the pollen-sac, which eventually divides to form the male cells.