CELL DIVISION
MEIOSIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an error in either egg or sperm meiotic anaphase
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failure of the egg nucleus to be fertilized by the sperm
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fertilization of a 23 chromosome human egg by a 22 chromosome sperm of a closely related species
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an error in the alignment of chromosomes on the metaphase plate
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Detailed explanation-1: -A zigote has 45 chromosomes, instead of a normal 46.
Detailed explanation-2: -Which of the following might result in a human zygote with 45 chromosome? An error in either egg or sperm meiotic anaphase.
Detailed explanation-3: -Egg and sperm cells have just 23 chromosomes each. That’s half as many chromosomes as regular cells. Through the process of fertilization, egg and sperm join to make a cell with 46 chromosomes (23 pairs), called a zygote.
Detailed explanation-4: -Chromosomes sometimes fail to separate during meiosis, a phenomenon known as nondisjunction. As a result, one haploid daughter gamete contains both members of a chromosomal pair for a total of 24 chromosomes, whereas the other haploid gamete contains only 22 chromosomes (Fig. 1.7).