Question

The embryo sac of an angiosperm is made up of
A) 8 cells
B) 7 cells and 8 nuclei
C) 8 nuclei
D) 8 cells and 7 nuclei

Answer 1

Angiosperms are the seed bearing vascular flowering plants. They are the largest phylum in kingdom Plantae. The gametophyte of the angiosperm is called embryo sac.

Complete answer:
The division of the megaspore nucleus results in the formation of embryo sac. It contains six haploid cells without cell walls and two haploid cells. During fertilization, the combination of a female nuclei and a male nuclei results in the formation of zygote which leads to embryo development. Matured embryo sac consists of four cell types, they are:

One egg cell
Two synergid cells
Central cell with two polar nuclei
Three antipodal cells
In total an embryo sac consists of 7 cells and 8 nuclei.

Additional information: Angiosperms undergo a complex fertilization mechanism called double fertilization. In this process, two male gametes produced by the pollen grains combine with a female gamete to form a diploid zygote. The development of zygote results in the formation of a new plant.

Hence the correct answer is (B) 7 cells and 8 nuclei.

Note: Remember that each cell in embryo sac haploid because, in angiosperms, the embryo sac that constitutes the female gametophyte is obtained from the megaspore cell through meiosis.