Haploid Structures in Plants

Plants have a unique reproductive system that involves the production of haploid structures through meiosis. These haploid structures eventually fuse to form a diploid zygote, which develops into a new plant.

Haploid structures are those that contain only one set of chromosomes, rather than the two sets found in diploid structures. In plants, the haploid structures are produced during the process of meiosis, which reduces the number of chromosomes in the cell by half.

Pairs of Haploid Structures

The question asks which of the following pairs has haploid structures. Let's examine each option:

a) Nucellus and antipodal cells - The nucellus is a haploid structure found within the ovule of a plant. Antipodal cells, on the other hand, are part of the embryo sac and are typically triploid, meaning they contain three sets of chromosomes. Therefore, this pair does not have haploid structures.

b) Antipodal cells and egg cell - As mentioned above, antipodal cells are typically triploid and therefore not haploid. The egg cell, however, is haploid, as it is produced through meiosis. Therefore, this pair has one haploid structure and one triploid structure.

c) Antipodal cells and megaspore mother cell - Antipodal cells are typically triploid, while the megaspore mother cell is haploid, as it is produced through meiosis. Therefore, this pair has one haploid structure and one triploid structure.

d) Nucellus and primary endosperm nucleus - As mentioned above, the nucellus is a haploid structure found within the ovule of a plant. The primary endosperm nucleus, on the other hand, is triploid, as it is formed by the fusion of three haploid nuclei. Therefore, this pair does not have haploid structures.

Conclusion

Based on the above analysis, the correct answer is option D - Nucellus and primary endosperm nucleus. This pair does not have haploid structures, as the primary endosperm nucleus is triploid.

Egg cell and antipodal cells haploid number of chromosomes . Angiosperms a singal diploid megaspore mother cells mature with in an ovule .
Through meiosis . It gives rise to four megaspore (Haploid).