If both parents are heterozygous for a trait. the probability that an offspring will be recessive for that trait is?
- 1/2
-
1/4
- 1
- 3/4
The correct answer is: B
Explanation
In genetics, when both parents are heterozygous for a trait (Aa), the possible combinations for their offspring can be AA, Aa, aA, or aa. The probability of an offspring being homozygous recessive (aa) is 1 out of 4, or 1/4. So, the correct answer is '1/4'.
If both parents are heterozygous for a trait, the probability that an offspring will be recessive for that trait is 25%. When both parents are heterozygous (meaning they carry both the dominant and recessive alleles), there is a 1 in 4 chance that an offspring will inherit two recessive alleles and express the recessive phenotype.
Heterozygous: An individual carrying both a dominant and a recessive allele for a trait.
Recessive trait: A trait that is only expressed when an individual inherits two copies of the recessive allele.