SEX LIMITED TRAITS

SEX LIMITED TRAITS

16.  SEX LIMITED TRAITS

When the characters are physically expressed in one sex only. That is known as a sex-limited trait. But the gene is present in both the sexes. In the presence of hormones, sex-limited genes are activated. These are autosomal traits. In the presence of androgens (male hormones), the beard controlling gene is activated. That mean the secondary sexual characters like beard presence in male human beings and absence in female human beings is due to the absence of androgen hormones.
As we know, the milk secretion genes are present in male and female, both the sexes. But only milk is secreted from female mammals. And the egg-laying genes are present in both (males and females) the sexes of birds but the egg is laying by only female birds.
The sex-limited trait is autosomal, that means genes are not present on the X or Y chromosomes. That is expressed in only one sex. The characters limited to only one sex (gender) due to hormone differences or anatomical difference is known as the sex-limited trait.


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