Question 1

Which of the following best describes the multiplication rule in probability as applied to genetics?

Accepted Answer

The probability that two or more independent events will occur together is the product of their individual probabilities. $$P(A 	ext{ and } B) = P(A) 	imes P(B)$$

Question 2

A cross between a true-breeding red snapdragon ($$C^R C^R) $$and a true-breeding white snapdragon ($$C^W C^W) $$produces F1 offspring that are all pink ($$C^R C^W). $$What type of inheritance is this an example of?

Accepted Answer

Incomplete dominance

Question 3

In the ABO blood group system, a person with genotype $$I^A I^B$$ will have which blood type, and why?

Accepted Answer

Type AB, because both $$I^A$$ and $$I^B$$ alleles are codominant and both carbohydrates are expressed on the red blood cell surface.

Question 4

Which of the following is an example of pleiotropy?

Accepted Answer

A single gene mutation causing cystic fibrosis, which affects the lungs, pancreas, and sweat glands.

Question 5

In Labrador retrievers, coat color is determined by two genes: one for pigment color (B/b) and one for pigment deposition (E/e). What is the expected phenotypic ratio in the offspring of a dihybrid cross ($$BbEe 	imes BbEe) if $$epistasis is involved?

Accepted Answer

$$9:3:4 ($$black:brown:yellow)

Question 6

A couple, both carriers for a recessive genetic disorder, want to know the probability that their child will be affected. What is the probability, and which rule do you use to calculate it?

Accepted Answer

The probability is $$\frac{1}{4}$$, using the multiplication rule: $$P(aa) = P(a 	ext{ from mom}) 	imes P(a 	ext{ from dad}) = \frac{1}{2} 	imes \frac{1}{2} = \frac{1}{4}.$$

Question 7

Which of the following best explains why human genetic research is more challenging than research with pea plants?

Accepted Answer

Humans have longer generation times and produce fewer offspring, making statistical analysis more difficult.

Question 8

A pedigree shows a trait that appears in every generation. What is the most likely mode of inheritance?

Accepted Answer

Dominant

Question 9

Which of the following is an example of a multifactorial disorder?

Accepted Answer

Heart disease, because it is influenced by both genetic and environmental factors.

Question 10

A Siamese cat has darker fur on its ears, tail, and paws due to a temperature-sensitive allele. What does this illustrate?

Accepted Answer

The environment can influence the expression of genetic traits.

Question 11

If a genetic counselor determines that both parents are carriers for a recessive disorder, what is the probability that their child will be a carrier?

Accepted Answer

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

Question 12

Which fetal testing method allows for earlier detection of genetic disorders but carries a slightly higher risk of miscarriage?

Accepted Answer

Chorionic villus sampling (CVS)

Question 13

Which of the following best describes polygenic inheritance?

Accepted Answer

A single trait is affected by multiple genes, often resulting in continuous variation.

Question 14

In a monohybrid cross, what is the probability of obtaining a heterozygous offspring if both parents are heterozygous ($$Aa 	imes Aa$$)?

Accepted Answer

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

Question 15

Which scenario is an example of codominance?

Accepted Answer

A person with genotype $$I^A I^B$$ expresses both A and B antigens on their red blood cells.

Question 16

Which of the following best explains why the blending hypothesis is not supported by the results of Mendelian crosses?

Accepted Answer

True-breeding parental phenotypes reappear in the F2 generation, indicating that genetic information is not lost or blended.

Question 17

If a woman who is a carrier for spinal muscular atrophy (recessive) has children with a man who is not a carrier, what is the probability that their child will be affected?

Accepted Answer

0

Question 18

Which of the following is true about carriers in recessive genetic disorders?

Accepted Answer

Carriers have one normal and one mutated allele and do not express the disorder.

Question 19

Which rule would you use to calculate the probability of obtaining either a heterozygous or a homozygous dominant offspring in a cross between two heterozygotes ($$Aa 	imes Aa$$)?

Accepted Answer

Addition rule: $$P(Aa) + P(AA) = \frac{1}{2} + \frac{1}{4} = \frac{3}{4}$$

Bio 100 LEC Chapter 14 Module 2-4

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드