AP BIOLOGY

Detailed explanation-1: -Thus, the correct answer is ‘18 singular chromosomes.

Detailed explanation-2: -Chromosome analysis revealed that worms belonging to different populations and color morphs, with dividing spermatogonia having 20 chromosomes in the diploid set (2n = 20) (Fig. 4a).

Detailed explanation-3: -The number of chromosomes does not correlate with the apparent complexity of an animal or a plant: in humans, for example, the diploid number is 2n = 46 (that is, 23 pairs), compared with 2n = 78, or 39 pairs, in the dog and 2n = 36 (18) in the common earthworm.

Detailed explanation-4: -Meiosis results in reduction of chromosome number to one half in the normal diploid cell. Thus, if a cell has 36 chromosome before meiosis. After meiosis the four daughter cells produced will be having 18 chromosomes each.

Detailed explanation-5: -In humans, diploid cells or 2n= 46 (or, 23 pairs of chromosomes), in dogs, 2n=78 (or 39 pair of chromosomes), in the earthworm, 2n=36 (or, 18 pairs of chromosomes) and in E.