A scientist is studying a cross between plants that are heterozygous (Xx) for a certain trait. She will use a table similar to t
his one to make a Punnett square for the cross.
Which percentage of offspring will most likely have the genotype represented by the letter A in this table?
O 0%
O 25%
O 50%
O 75%
Which percentage of offspring will most likely have the genotype represented by the letter A in this table?
O 0%
O 25%
O 50%
O 75%
2 answers:
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Answer:
0%
Explanation:
This question involves a gene coding for height in pea plants. The allele for tallness (T) is dominant over the allele for shortness (t). This means that allele T will be expressed over allele t in an heterozygous state.
A purebred tall plant will possess genotype: TT while a heterozygous tall plant will possess genotype: Tt. The two parents will produce the following gametes:
TT- T and T
Tt- T and t
Using these gametes in a punnet square (see attached image), the following offsprings with genotypes: TT and Tt in a ratio 1:1 will be produced.
TT offsprings are purebreed tall while Tt offsprings are heterozygous tall. Hence, based on the question, no offsprings of this cross will possess the recessive genotype (tt). This means that 0% of the offsprings of this cross will be short.
