CELL DIVISION
MEIOSIS AND GENETIC VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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D
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d
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Dd
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dd
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Detailed explanation-1: -Therefore, you have a total of two alleles for this gene. Suppose that the GENOTYPE (the genetic makeup for this trait) of Sam is “DD". He is HOMOZYGOUS (has 2 identical alleles for that gene) for the dimples gene. Sally’s genotype is “dd", so she is also considered homozygous.
Detailed explanation-2: -Individuals who are homozygous dominant (DD) or heterozygous (Dd) are Rh+. Those who are homozygous recessive (dd) are Rh-(i.e., they do not have the key Rh antigens). Clinically, the Rh factor, like ABO factors, can lead to serious medical complications.
Detailed explanation-3: -The mother has a genotype Dd and the father’s genotype is DD. Therefore the mother’s alleles are D and d and the father’s are D and D. The only possible combinations of these alleles in the children is DD or Dd. Since dimples are dominant and represented by the letter D, all the children will have dimples.