CLEP Biology Mendelian Inheritance Patterns 2

Question 1

In a dihybrid cross between two heterozygous parents (AaBb × AaBb), what fraction of offspring are expected to be homozygous recessive for both traits (aabb)?

Accepted Answer

1/16

Answer

3/16

Answer

9/16

Answer

1/4

Question 2

A man with blood type A (genotype I^A i) and a woman with blood type B (genotype I^B i) have children. What is the probability that a child will have blood type O?

Accepted Answer

1/4

Answer

1/2

Answer

3/4

Answer

0

Question 3

Which of the following best describes the concept of 'gene interaction' in the context of epistasis?

Accepted Answer

One gene masks or modifies the expression of another gene

Answer

Two genes on the same chromosome assort together

Answer

A single gene controls multiple phenotypic traits

Answer

Alleles at one locus blend to produce an intermediate phenotype

Question 4

A plant with red flowers (RR) is crossed with a white-flowered plant (rr), producing all pink offspring (Rr). This pattern of inheritance is an example of:

Accepted Answer

Incomplete dominance

Answer

Codominance

Answer

Complete dominance

Answer

Epistasis

Question 5

In humans, the allele for attached earlobes (a) is recessive to free earlobes (A). Two parents with free earlobes have a child with attached earlobes. What are the genotypes of the parents?

Accepted Answer

Aa × Aa

Answer

AA × Aa

Answer

AA × AA

Answer

Aa × aa

Question 6

The law of segregation states that:

Accepted Answer

Allele pairs separate during gamete formation so each gamete carries only one allele per gene

Answer

Genes on different chromosomes assort independently during meiosis

Answer

The dominant allele always masks the recessive allele in heterozygotes

Answer

Traits blend together in offspring of two different parents

Question 7

If a trait is autosomal recessive, which of the following pedigree observations would be INCONSISTENT with that inheritance pattern?

Accepted Answer

An affected father passing the trait directly to all sons

Answer

An affected child with two unaffected parents who are carriers

Answer

Skipping of generations (trait appears in grandchild but not parent)

Answer

Equal frequency of the trait in males and females