HEREDITY
NONDISJUNCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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inheriting three copies of a specific chromosome
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inheriting three complete sets of chromosomes
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when three chromosomes fuse together
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when a child inherits one less than the normal diploid number
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Detailed explanation-1: -The term “trisomy” is used to describe the presence of an extra chromosome-or three instead of the usual pair. For example, trisomy 21 or Down syndrome occurs when a baby is born with three #21 chromosomes. In trisomy 18, there are three copies of chromosome #18 in every cell of the body, rather than the usual pair.
Detailed explanation-2: -Trisomy (’three bodies’) means the affected person has three copies of one of the chromosomes instead of two. This means they have 47 chromosomes instead of 46. Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy.
Detailed explanation-3: -Triploidy is a rare chromosomal abnormality. Triploidy is the presence of an additional set of chromosomes in the cell for a total of 69 chromosomes rather than the normal 46 chromosomes per cell. The extra set of chromosomes originates either from the father or the mother during fertilization.
Detailed explanation-4: -Each cell normally contains 23 pairs of chromosomes, which carry the genes you inherit from your parents. But a baby with Patau’s syndrome has 3 copies of chromosome 13, instead of 2. This severely disrupts normal development and, in many cases, results in miscarriage, stillbirth or the baby dying shortly after birth.