Which of the following statements regarding angiosperms is incorrect?

Megaspore is diploid

The correct answer is Option (1) - Megaspore is diploid.

In angiosperms, the megaspore is not diploid. The megaspore is a haploid cell that undergoes further divisions to give rise to the female gametophyte, also known as the embryo sac. During megasporogenesis, a diploid megaspore mother cell undergoes meiosis, resulting in the formation of four haploid megaspores. Typically, three of the megaspores degenerate, and only one megaspore survives and develops into the female gametophyte.

B) Megaspore is the first cell of the female gametophyte.

This statement is correct. The surviving megaspore develops into the female gametophyte, which is also called the embryo sac. The embryo sac is a multicellular structure that contains the female gametes and is responsible for the development of the female reproductive structures in the flower.

C) The pollen grains represent the male gametophytes.

This statement is correct. The pollen grains represent the male gametophytes. As the anther develops, the cells of the sporogenous tissue undergo meiotic divisions to form microspore tetrads. As each cell of the sporogenous tissue is capable of giving rise to a microspore tetrad. 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. The microspores, as they are formed, are arranged in a cluster of four cells–the microspore tetrad. As the anthers mature and dehydrate, the microspores dissociate from each other and develop into pollen grains . Inside each microsporangium several thousands of microspores or pollen grains are formed that are released with the dehiscence of anther,
The pollen grains represent the male gametophytes. When the pollen grain is mature it contains two cells, the vegetative cell and generative cell. In over 60 per cent of angiosperms, pollen grains are shed at this 2-celled stage. In the remaining species, the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage).