Question

How many linkage groups are present in the female and male grasshopper insect?
(a)04 and 04
(b)10 and 10
(c)12 and 12
(d)23 and 24

Answer 1

Hint: In genetics, a linkage group represents all of the genes on a single chromosome. The number of linkage groups in a species will correspond with the haploid chromosome number of that particular species.

Complete answer:
Since all the genes of the same chromosome have identical genes or allelomorphs on the homologous chromosome, the linkage groups of a homologous pair of chromosomes are considered as one. In male and female grasshoppers, they have a varying number of chromosomes.
Males have a total of 23 chromosomes seen as 22 + XO as sex chromosomes.
So, the haploid number will still have 12 as they could be inherited as 11+X.
Hence the number of linkage groups in a male grasshopper is 12.
Female grasshoppers have a total of 24 chromosomes seen as 22+XX.
But since they have two similar sex chromosomes, it is considered as one and hence the haploid number is unchanged with 11+X.
So, the number of linkage groups in a female grasshopper too is 12.

So, the correct answer is, ’ 12 and 12.’

Note: In human females, the total number of chromosomes is 46 with 22 pairs of autosomes and one pair of homomorphic sex chromosomes.
So, the number of linkage groups is 23.
Whereas, human males have 22 pairs of autosomes and 2 heteromorphic or different sex chromosomes.
So, the linkage groups in males will be 22 autosomes + 1 X-chromosome + 1 Y-chromosome;
thus taking the total number of linkage groups to 24.