GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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both X and Y chromosomes
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either X or Y chromosomes
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only X chromosomes
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only Y chromosomes
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Detailed explanation-1: -The sperm that fertilizes the egg determines the sex of the resulting zygote: eggs have a single X chromosome, whereas the sperm can have either an X or a Y.
Detailed explanation-2: -Every egg has an X sex chromosome; a sperm can have either an X or a Y sex chromosome. If the sperm that fertilizes an egg has an X chromosome, the baby is female; if it has a Y chromosome, the baby will be a boy.
Detailed explanation-3: -The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome. The 22 autosomes are numbered by size. The other two chromosomes, X and Y, are the sex chromosomes.
Detailed explanation-4: -Complete answer: A normal human cell has 22 pairs of autosomes and 2 sex chromosomes, but the ovum is formed by the meiosis due to which they have only the half number of chromosomes, which means 22 autosomes (11 pairs) and 1 sex chromosome.
Detailed explanation-5: -The father’s contribution can either be an X or a Y chromosome. A baby girl usually has 2 X chromosomes (XX), and boys have an X and a Y chromosome (XY). A female with Turner syndrome is missing part or all of 1 sex chromosome. This means she has just 1 complete X chromosome.