CELL DIVISION
MEIOSIS AND GENETIC VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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When a genotype has a dominant and recessive allele
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When a genotype has 2 copies of the recessive allele
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When a genotype has 2 copies of the dominant allele
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Detailed explanation-1: -A homozygous plant contains either of the following alleles for seed shape: (RR) or (rr). The (RR) genotype is homozygous dominant and the (rr) genotype is homozygous recessive for seed shape.
Detailed explanation-2: -An organism with one dominant allele and one recessive allele is said to have a heterozygous genotype. In our example, this genotype is written Bb. Finally, the genotype of an organism with two recessive alleles is called homozygous recessive. In the eye color example, this genotype is written bb.
Detailed explanation-3: -rr. An individual who carries two copies of the same allele (i.e. RR or rr) is called a homozygote (homo = same, zygote = embryo). Homozygotes produce genoctypially identical offspring when allowed to self-fertilize. There are dominant homozygotes (i.e. RR individuals) and recessive homozygotes (i.e. rr individuals).
Detailed explanation-4: -Individuals carrying two identical alleles (RR or rr) are known as homozygous. While individual organisms bearing different alleles (Rr) are known as heterozygous.