Question 1

Which of the following best describes Mendel’s law of segregation?

Accepted Answer

Alleles for a gene separate during gamete formation, so each gamete receives only one allele.

Question 2

A pea plant with genotype Pp is crossed with another Pp plant. What is the expected phenotypic ratio of their offspring if purple (P) is dominant to white (p)?

Accepted Answer

$$3:1$$

Question 3

In a testcross between a black dog of unknown genotype (B?) and a chocolate dog (bb), half the puppies are black and half are chocolate. What is the genotype of the black parent?

Accepted Answer

Bb

Question 4

Which statement about incomplete dominance is correct?

Accepted Answer

The heterozygote displays a phenotype intermediate between the two homozygotes.

Question 5

A dihybrid cross between two RrYy pea plants produces a 9:3:3:1 phenotypic ratio. Which principle does this illustrate?

Accepted Answer

Law of independent assortment

Question 6

Which of the following best explains why a trait can disappear in one generation and reappear in the next?

Accepted Answer

Alleles retain their identity and segregate independently during gamete formation.

Question 7

If a plant with genotype RR (red flowers) is crossed with a plant with genotype rr (white flowers) and the F1 generation is all pink, what type of inheritance is this?

Accepted Answer

Incomplete dominance

Question 8

Which of the following is true about homologous chromosomes?

Accepted Answer

They carry the same genes at the same loci but may have different alleles.

Question 9

A woman wants to trace her maternal ancestry. Which genetic marker should she analyze?

Accepted Answer

Mitochondrial DNA

Question 10

Which event during meiosis explains Mendel’s law of independent assortment?

Accepted Answer

Random orientation of homologous chromosome pairs at metaphase I

Question 11

If a gene is located on the X chromosome, which of the following is true about its inheritance?

Accepted Answer

Males are more likely to express recessive X-linked traits because they have only one X chromosome.

Question 12

Which of the following best describes a genotype?

Accepted Answer

The combination of alleles an organism carries for a gene.

Question 13

A true-breeding plant with white flowers is crossed with a true-breeding plant with purple flowers. All F1 offspring have purple flowers. What does this indicate about the purple allele?

Accepted Answer

It is dominant to the white allele.

Question 14

Which of the following is a real-world example of the law of independent assortment?

Accepted Answer

A person can inherit brown eyes and attached earlobes independently.

Question 15

If a man is suspected to be a descendant of a famous historical figure based on a shared Y-chromosome marker, what is the limitation of this evidence?

Accepted Answer

A shared marker only indicates shared ancestry, not a specific named ancestor.

Question 16

Which cross would you use to determine if a plant with a dominant phenotype is homozygous or heterozygous?

Accepted Answer

Cross it with a homozygous recessive plant.

Question 17

In a population, the probability of producing a white-flowered pea plant from two heterozygous parents (Pp × Pp) is:

Accepted Answer

$$\frac{1}{4}$$

Question 18

Which of the following best explains why small sample sizes in genetic crosses may not reflect expected ratios?

Accepted Answer

Probability predicts outcomes over many offspring, not exact ratios in every family.

Question 19

Which of the following is NOT a feature of Mendel’s experimental approach?

Accepted Answer

He blended pollen from multiple plants to ensure genetic diversity.

Question 20

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are different versions of a gene found at the same locus on homologous chromosomes.

Patterns of Inheritance: Mendelian Genetics and Beyond

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