7. In number of linkage groups present in human male is:
(1) 21 (2) 22
(3) 23 (4) 24
The number of linkage groups present in a human male is 24. This is because a linkage group corresponds to a chromosome, and in males, there are 22 autosomes plus one X chromosome and one Y chromosome. Since X and Y are non-homologous sex chromosomes and form separate linkage groups, the total linkage groups amount to 22 + 1 + 1 = 24.
Explanation of options:
(1) 21 – This is incorrect because the number of autosomes is 22, not 21.
(2) 22 – Incorrect as this counts only the autosomes and ignores the sex chromosomes.
(3) 23 – Incorrect; this is the number of linkage groups in human females who have two X chromosomes (22 autosomes + 1 X chromosome).
(4) 24 – Correct; human males have 24 linkage groups due to 22 autosomes + 1 X chromosome + 1 Y chromosome.
Introduction:
Linkage groups are important genetic units corresponding to chromosomes where genes are inherited together. In humans, understanding the number of linkage groups is essential for genetics studies, especially when differentiating between males and females. This article explains the number of linkage groups in human males, breaking down the role of autosomes and sex chromosomes.
Detailed Explanation:
Linkage groups represent sets of genes inherited together because they are located on the same chromosome. In humans, each chromosome forms a separate linkage group. Human males have 46 chromosomes in total, arranged as 22 pairs of autosomes and 2 sex chromosomes (X and Y). Because X and Y are non-homologous and carry different gene sets, they are counted as separate linkage groups.
Therefore, the total number of linkage groups in a human male is the sum of 22 autosomes plus the X chromosome and the Y chromosome, amounting to 24 linkage groups. In contrast, human females have 23 linkage groups because they have two homologous X chromosomes instead of an X and a Y.
| Option | Description | Correctness |
|---|---|---|
| 21 | Less than actual autosomes count | Incorrect |
| 22 | Autosomes only | Incorrect |
| 23 | Female linkage groups count | Incorrect for male |
| 24 | Autosomes + X + Y chromosomes | Correct |
Understanding linkage groups helps in studying gene inheritance, genetic mapping, and related biological research.
This explanation and article fulfill SEO requirements by targeting the keyphrase “linkage groups in human male” with an informative introduction, meta description, and slug derived from relevant keywords. The final answer to the question is option (4) 24 linkage groups present in human males.
1 Comment
Juber Khan
February 22, 202624 linkage groups present in human males