HEREDITY
SEX LINKAGE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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All boys have two Y chromosomes.
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Everybody has at least one X chromosome.
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Girls have a Y chromosome and an X chromosome.
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Nobody has two X chromosomes.
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Detailed explanation-1: -Each person normally has one pair of sex chromosomes in each cell.
Detailed explanation-2: -Human follows XX-XY mechanism of sex determination wherein females have XX and males have XY sex chromosomes. During meiosis, all the gametes produced by females contain only the X chromosome (22 A + X), whereas males produce two kinds of gametes, 1/2 gametes with X-and 1/2 with Y-chromosome (22 A + X and 22 A + Y).
Detailed explanation-3: -6-12). Thus all diploid somatic cells in both males and females have a single active X chromosome, regardless of the total number of X or Y chromosomes present.
Detailed explanation-4: -Which statement is true concerning X chromosomes? They have genes that are not found on the Y chromosome.
Detailed explanation-5: -Humans have 22 pairs of numbered chromosomes (autosomes) and one pair of sex chromosomes (XX or XY), for a total of 46.