Question 1

Which of the following best describes Mendel's 'particulate' hypothesis of heredity?

Accepted Answer

Parents pass on discrete heritable units (genes) that retain their identity across generations.

Question 2

In Mendel's pea plant experiments, what was the phenotypic ratio observed in the F$$_2$$ generation when crossing two F$$_1$$ hybrids for flower color?

Accepted Answer

$$3:1$$

Question 3

If a pea plant with genotype Tt (tall) is self-pollinated, what is the probability that an offspring will be homozygous recessive (tt)?

Accepted Answer

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

Question 4

Which of the following statements correctly explains the Law of Segregation?

Accepted Answer

The two alleles for a heritable character separate during gamete formation and end up in different gametes.

Question 5

A testcross is performed between a pea plant with purple flowers of unknown genotype and a white-flowered plant (pp). If half the offspring have purple flowers and half have white flowers, what is the genotype of the purple-flowered parent?

Accepted Answer

Pp

Question 6

In a dihybrid cross between YyRr x YyRr, what is the probability of obtaining an offspring with genotype YYRR?

Accepted Answer

$$\frac{1}{16}$$

Question 7

Which rule would you use to calculate the probability that an F$$_2$$ plant from a monohybrid cross will be heterozygous (Rr) rather than homozygous (RR or rr)?

Accepted Answer

Addition rule

Question 8

A couple, both heterozygous for cystic fibrosis (a recessive disorder), want to know the probability that their child will be affected. What is the probability?

Accepted Answer

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

Question 9

Which of the following is an example of incomplete dominance?

Accepted Answer

A cross between red and white snapdragons produces pink flowers.

Question 10

Which statement about dominant alleles is correct?

Accepted Answer

Dominant alleles determine the phenotype in heterozygotes.

Question 11

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

Accepted Answer

$$\frac{1}{2}$$

Question 12

Which of the following best illustrates pleiotropy?

Accepted Answer

A single gene affects multiple, seemingly unrelated traits, such as in sickle-cell disease.

Question 13

In a cross between two heterozygous snapdragons ($$C^R C^W$$), what is the expected phenotypic ratio of red:pink:white flowers in the F$$_2$$ generation?

Accepted Answer

$$1:2:1$$

Question 14

Which of the following is true regarding the Law of Independent Assortment?

Accepted Answer

It states that alleles of different genes segregate independently during gamete formation.

Question 15

If two parents are both heterozygous for two genes (AaBb x AaBb), what is the probability that their child will be homozygous recessive for both genes (aabb)?

Accepted Answer

$$\frac{1}{16}$$

Question 16

Which scenario best demonstrates codominance?

Accepted Answer

A person with genotype $$L^M L^N$$ expresses both M and N antigens on red blood cells.

Question 17

Which of the following is NOT an advantage of using pea plants for genetic studies, as Mendel did?

Accepted Answer

Pea plants have a long generation time.

Question 18

A woman with genotype $$I^A i$$ and a man with genotype $$I^B i$$ have a child. What is the probability that the child will have blood type AB?

Accepted Answer

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

Question 19

Which of the following best describes the relationship between genotype and phenotype in Tay-Sachs disease?

Accepted Answer

At the biochemical level, the phenotype is incompletely dominant.

Mendelian Genetics: Principles, Laws, and Patterns of Inheritance

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