HEREDITY
THE PEDIGREE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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1:2:1
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2:1:1
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0:3:1
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0:2:2
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Detailed explanation-1: -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. Hence, the correct answer is ‘1 tall : 1 dwarf’
Detailed explanation-2: -F2 Genotypic ratio =1 pure tall (TT) : 2 heterozygous tall (Tt) : 1 pure dwarf (tt); thus, the ratio of pure tall to pure short plants will be 1:1.
Detailed explanation-3: -As shown in the figure a cross between two heterozygous tall plants results in 25% homozygous tall, 50% heterozygous tall and 25% dwarf plants.
Detailed explanation-4: -So, the correct option is ‘50%’.
Detailed explanation-5: -When two heterozygous pea plants ( Yy ) are crossed the offsprings will be 75% ( 3/4 ) dominant and 25% (1/4) recessive according to punnet square i.e, YY, Yy and Yy. So, if 1000 individuals are produced than 750 will be dominant.