Question 1:

In Mendelian genetics, a dominant trait is represented by which letter?

Explanation: B) In Mendelian genetics, a dominant trait is represented by the capital letter A. This is used to denote the presence of the dominant allele, which masks the expression of the recessive allele.

Question 2:

If an individual expresses a recessive trait, what can be concluded about their genotype?

Explanation: C) If an individual expresses a recessive trait, it can be concluded that the individual must be homozygous for the recessive allele. This is because the recessive trait is only expressed when both alleles in the genotype are recessive.

Question 3:

Which of the following statements about dominant traits is true?

Explanation: C) Dominant traits can be masked by the presence of a recessive allele. While dominant traits are expressed in individuals with at least one dominant allele, the presence of a recessive allele can hide the expression of the dominant trait.

Question 4:

In a cross between two individuals heterozygous for a dominant trait (Aa x Aa), what is the probability of producing offspring with the recessive phenotype?

Explanation: B) In a cross between two individuals heterozygous for a dominant trait (Aa x Aa), the probability of producing offspring with the recessive phenotype is 25%. This is because both parents carry a recessive allele and can pass it on to their offspring, resulting in a 1 in 4 chance of a recessive phenotype.

Question 5:

Which of the following traits is an example of a recessive trait in humans?

Explanation: B) Attached earlobes. In humans, the trait of attached earlobes is an example of a recessive trait. It is masked by the presence of the dominant trait of free earlobes, which is more common in the population.