AP BIOLOGY

Detailed explanation-1: -The haploid gametes fuse to form diploid zygote that is, the fertilization restored the diploid chromosomal number. Now, the number of chromosomes in the zygote is 28. Thus, the number of chromosomes in gametes must be half of 28 that is, 14.

Detailed explanation-2: -The number of chromosomes in the gamete is haploid and human gametes contain 23 chromosomes. As zygote is from the fusion of two gametes, the chromosome number is diploid and is double of that in gamete and thus has 46 chromosomes.

Detailed explanation-3: -The total number of chromosomes is referred to as the chromosome number. The haploid number in humans is given as 2n=46, n = 23, this is because the haploid human cells possess one set of 23 chromosomes – 22 sets of autosomal chromosomes (non-sex chromosomes) and 1 set of sex chromosomes.

Detailed explanation-4: -So, if we are starting from 4 chromosomes, it means that the diploid number of chromosomes in the parent somatic cell is 4. This means that there are 2 sets of chromosomes present in the cell. So, the haploid number of chromosomes shall correspond to a single set of chromosomes, i.e. only 2 chromosomes.

Detailed explanation-5: -2n = 16, n is the haploid number of chromosomes. 2n = 16, it means n = 8. The haploid number of chromosomes is 8.