GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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1 homozygous tall:3 heterozygous tall
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1 homozygous tall:1 heterozygous tall
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3 homozygous tall:1 heterozygous tall
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All heterozygous tall
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Detailed explanation-1: -The selfing of heterozygous tall plants yields F2 generation with the genotypic ratio of 1 TT (homozygous tall): 2 Tt (heterozygous tall): 1 tt (homozygous dwarf). Thus, the correct answer is option B.
Detailed explanation-2: -In a cross between heterozygous tall plants (Tt) and a homozygous dwarf plant (tt), the ratio in the offspring shall be 1 tall : 1 dwarf. This is because the heterozygous plant will make two types of gametes, one type having T allele and the other having t allele.
Detailed explanation-3: -So, the correct option is ‘50%’.
Detailed explanation-4: -A homozygous short pea plant will have the genotype tt. A cross between a homozygous tall tree plant and a homozygous short tree plant will give the following genotypes of the offspring: 100% Tt. Since the offspring has at least one allele that is dominant for tall trees, all the offspring will be tall.