Question

In Polygonum type of embryo sac, the sac cells are
A) Haploid
B) Diploid
C) Both A and B
D) Polyploid

Answer 1

Hint: Diploid is a cell or organism that has a pair of chromosomes, one from each parent. Haploid is a cell or organism that has only one copy of each chromosome.

Complete answer:
The diploid cells have two homologous versions of the two chromosomes formed by two parents. The cells are formed due to mitotic cell division. It is almost like they have half the number of chromosomes when compared to diploid cells.
A diploid Megaspore mother cell gets formed inside the nucleus. It then undergoes a meiotic division in order to form four haploid megaspores. When four megaspores are formed, three of them degenerate and only one remains active. This functioning megaspore then undergoes mitosis three times without cytoplasmic differentiation, resulting in 8 nuclei in the megaspore. Three of these 8 nuclei are arranged into an egg apparatus at the micropylar pole. Two nuclei form a big central cell and three nuclei are arranged in antipodal cells at the chalazal pole. The two polar nuclei are merged before fertilisation, resulting in the development of a secondary diploid nucleus. This results in the development of a 7-cell but 8-nucleate structure called the embryo sac. As a result, both haploid and diploid cells are present in the polygonal embryo sac form.

Hence the correct answer is option (C)

Note:Haploid cells are produced after division of meiosis during sexual reproduction. During the division of meiosis, the diploid cell replicates its chromosomes to create four sets of chromosomes. The cell divides to create four cells with a single set of chromosomes.