Which one of the following pairs of plant structures has a haploid number of chromosomes?
Which one of the following pairs of plant structures has a haploid number of chromosomes?
The correct option is D Egg cell and antipodal cells
The megaspore mother cell (diploid) is situated in the ovule. Out of the 4 megaspores it produces, one develops into the embryo sac; the others abort.
It is the site of fertilization of the egg cell and development of the embryo. It consists of 6 haploid cells (2 synergids, 3 antipodal cells, and an egg cell) and 2 haploid nuclei (polar nuclei). The haploid nuclei fuse to form the secondary nucleus or the central cell.
At the time of fertilization, the pollen tube contains two male gametes. One of these male gametes fuses with the egg cell (haploid) and forms a diploid zygote while the other male gamete fuses with the polar nuclei (secondary nucleus - diploid) located in the centre of the embryo sac to produce a triploid primary endosperm nucleus, which later on develops into endosperm. Hence, antipodal cells are haploid while endosperm is triploid.
Egg cell and antipodal cells
The megaspore mother cell (diploid) is situated in the ovule. Out of the 4 megaspores it produces, one develops into the embryo sac; the others abort.
It is the site of fertilization of the egg cell and development of the embryo. It consists of 6 haploid cells (2 synergids, 3 antipodal cells, and an egg cell) and 2 haploid nuclei (polar nuclei). The haploid nuclei fuse to form the secondary nucleus or the central cell.
At the time of fertilization, the pollen tube contains two male gametes. One of these male gametes fuses with the egg cell (haploid) and forms a diploid zygote while the other male gamete fuses with the polar nuclei (secondary nucleus - diploid) located in the centre of the embryo sac to produce a triploid primary endosperm nucleus, which later on develops into endosperm. Hence, antipodal cells are haploid while endosperm is triploid.
