GENETICS AND EVOLUTION
EVOLUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Natural selection
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the egg or the sperm
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the egg
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the sperm
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Detailed explanation-1: -The male, being XY, can generate two types of sperm: half bear the X chromosome, half the Y. If the egg receives another X chromosome from the sperm, the resulting individual is XX, forms ovaries, and is female; if the egg receives a Y chromosome from the sperm, the individual is XY, forms testes, and is male.
Detailed explanation-2: -Sex Determination in Mammals In placental mammals, the presence of a Y chromosome determines sex. Normally, cells from females contain two X chromosomes, and cells from males contain an X and a Y chromosome.
Detailed explanation-3: -The mother gives an X chromosome to the child. The father may contribute an X or a Y. The chromosome from the father determines if the baby is born as male or female.
Detailed explanation-4: -In mammals, females have two identical (XX) sex chromosomes while males have an X and Y (XY). In contrast, birds have a ZZ–ZW determination system wherein females are the heterogametic sex (ZW).