Identify each of the following structures as haploid or diploid.

(A) sporophyte

(B) spore

(C) gametophyte

(D) zygote

A cell is a haploid when it carries a single set of chromosomes denoted as ‘n.’ Those organisms which reproduce asexually are haploid. In humans, only the gametes are haploid; all other cells are diploid.

When a cell has two sets of chromosomes, it is called a diploid cell. One set of chromosomes is received from each parent in a diploid cell. Diploid organisms are those that reproduce sexually.

The two haploid gametes combine to form a zygote that undergoes mitotic cell division to produce a sporophyte. The sporophyte is a diploid stage in the life of plants and algae.

Since the zygote is a diploid cell thus the sporophyte phase is also diploid as it further leads to the formation of spores. Hence, the sporophyte is always diploid.

The process of meiosis in diploid sporophytes gives rise to haploid spores. The diploid cells are split in half during meiosis, dividing the chromosome into halves and creating two daughter cells. As a result, the spores are all haploid.

The gametophyte is a phase that leads to the formation of gametes. The gametophyte phase and the gametes both are haploid. Gametophytes are haploids as they possess a single pair of chromosomes and are produced by meiosis.

The zygote is formed by the fusion of the male and female gametes. The male and female gametes are in the haploid, so when they fuse, they become diploid, thus making the zygote diploid.