KCET 2018 Biology Solved Paper

In some species (about 33%), this division occurs before the release of pollen from the anther. These cells are three celled when the pollen grain is shed. However, in most species (more than 60%), this division is delayed till pollination occurs. Hence, pollen grain is shed at the two-celled stage.
The inner layer, intine is thin and continuous. It is deposited by the cytoplasm like the primary cell wall. It is for this reason that its composition is same as that of primary cytoplasm and it is made up of cellulose and pectin.