Question

Read the following four statements (A-D):
(i) The outer wall of the pollen grain is pecto-cellulosic in nature.
(ii) In pollen grain, the generative cell is bigger and contains abundant food reserve.
(iii) In all angiosperms, pollen grains are always shed at the 2-celled stage.
(iv) Usually, sporogenous cell directly behaves as the megaspore mother cell.
How many of the above statements are wrong?

• A. Four
• B. One
• C. Two
• D. Three

Answer 1

Answer: (A)

The inner wall of the pollen grain is called the intine. It is a thin and continuous layer made up of cellulose and pectin. The cytoplasm of pollen grain is surrounded by a plasma membrane. When the pollen grain is mature it contains two cells, the vegetative cell and generative cell. The vegetative cell is bigger, has abundant food reserve and a large irregularly shaped nucleus. The generative cell is small and floats in the cytoplasm of the vegetative cell. It is spindle shaped with dense cytoplasm and a nucleus. In over 60 per cent of angiosperms, pollen grains are shed at this 2-celled stage.
As the anther develops, the cells of the sporogenous tissue undergo meiotic divisions to form microspore tetrads. Each one is a potential pollen or microspore mother cell. The process of formation of microspores from a pollen mother cell (PMC) through meiosis is called microsporogenesis.