Q: A couple, both heterozygous for a recessive disease allele (Aa), have three children. What is the probability that exactly two of the children will be affected by the disease (aa)?

$$3 \times \left(\frac{1}{4}\$$right)^2$$ \times \left(\frac{3}{4}\$$right)^1$$ = \frac{9}{64}$$

Q: A plant with genotype Pp is self-fertilized. If 150 progeny are produced, how many are expected to have white flowers if purple (P) is dominant to white (p)?

$$\frac{1}{4} \times 150 = 37.5$$

Question 1

Which of the following best describes Mendel's Principle of Segregation?

Accepted Answer

Each individual has two alleles for a given trait, and these alleles separate during gamete formation so that each gamete receives only one allele.

Question 2

A woman with normal metabolism (genotype Aa) marries a man with alkaptonuria (genotype aa). What is the probability that their first child will have alkaptonuria?

Accepted Answer

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

Question 3

Which historical theory of inheritance proposed that all parts of the body produce 'seeds' that are transmitted to offspring at conception?

Accepted Answer

Pangenesis

Question 4

In a dihybrid cross between two heterozygous pea plants (RrYy x RrYy), what is the expected phenotypic ratio among the F2 progeny?

Accepted Answer

9:3:3:1

Question 5

A plant with genotype CcFf (yellow flowers, entire petals) is crossed with a plant with genotype ccff (white flowers, fringed petals). Assuming independent assortment, what is the expected proportion of offspring with yellow flowers and fringed petals?

Accepted Answer

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

Question 6

Which of the following statements about the molecular nature of alleles is correct?

Accepted Answer

Dominant alleles usually code for a functional protein, while recessive alleles often code for a defective or nonfunctional protein.

Question 7

If two heterozygous individuals (Rr) are crossed, what is the probability that their first two children will both be homozygous recessive (rr)?

Accepted Answer

$$\left(\frac{1}{4}\$$right)^2$$ = \frac{1}{16}$$

Question 8

Which of the following best explains the use of the chi-square ($$\$$chi^2$$) test in genetics?

Accepted Answer

It determines whether the difference between observed and expected values is likely due to chance.

Question 9

A couple, both heterozygous for a recessive disease allele (Aa), have three children. What is the probability that exactly two of the children will be affected by the disease (aa)?

Accepted Answer

$$3 	imes \left(\frac{1}{4}\$$right)^2$$ 	imes \left(\frac{3}{4}\$$right)^1$$ = \frac{9}{64}$$

Question 10

Which of the following is a key reason Mendel was successful in his genetic experiments?

Accepted Answer

He used mathematics to analyze results and tested hypotheses with additional crosses.

Question 11

In a cross between two individuals with genotypes AaBb x AaBb, what is the probability of producing an offspring with genotype aabb?

Accepted Answer

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

Question 12

Which of the following is NOT a correct application of the multiplication rule in genetics?

Accepted Answer

Calculating the probability of two mutually exclusive events both occurring.

Question 13

A plant with genotype Pp is self-fertilized. If 150 progeny are produced, how many are expected to have white flowers if purple (P) is dominant to white (p)?

Accepted Answer

$$\frac{1}{4} 	imes 150 = 37.5$$

Question 14

Which of the following best describes the Principle of Independent Assortment?

Accepted Answer

Alleles of different loci segregate independently of each other during gamete formation.

Question 15

If the observed ratio of phenotypes in a genetic cross deviates from the expected ratio, which of the following is the most appropriate first step?

Accepted Answer

Perform a chi-square ($$\$$chi^2$$) test to determine if the deviation is due to chance.

Question 16

In a family where both parents are heterozygous for a recessive disease (Aa), what is the probability that their first child is unaffected and the second child is affected?

Accepted Answer

$$\frac{3}{4} 	imes \frac{1}{4} = \frac{3}{16}$$

Question 17

Which of the following is a correct interpretation if a chi-square ($$\$$chi^2$$) test yields a p-value between 0.10 and 0.50?

Accepted Answer

There is a high probability that the difference between observed and expected values is due to chance.

Question 18

Which of the following best describes a heterozygote?

Accepted Answer

An individual possessing two different alleles at a locus.

Question 19

If Sally (genotype Aa) marries a man with alkaptonuria (genotype aa), what is the probability that their first three children will all have normal metabolism?

Accepted Answer

$$\left(\frac{1}{2}\$$right)^3$$ = \frac{1}{8}$$

Genetics: Course Syllabus and Foundational Concepts

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