17) In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?
A) 1
B) 1/2
C) 1/4
D) 1/6
E) 0
The probability that the offspring will be short is 0 (Option E).
In diploid organisms, offspring receive one gene variant or 'allele' of the same locus from each parent., ie., one allele from the mother and the other from the father.
An individual is homo-zygous when receives the same allele for a given locus of both parents, whereas an individual is heterozygous when receives two different alleles.
In complete dominance, the dominant allele (in this case, tall plant trait) completely masks the expression of the recessive allele in heterozygous individuals.
In consequence, a homo-zygous dominant parent will have a 100% of chance to pass the tall allele to the offspring.
In conclusion, the probability that the offspring will be short is 0 (Option E).
