Q: A geneticist is studying a population in Hardy-Weinberg equilibrium. If the frequency of the recessive allele ($$q) is 0.3$$, what is the expected frequency of heterozygotes?

$$2pq = 2 \times 0.7 \times 0.3 = 0.42$$

Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

A mutation in which type of gene is most likely to result in uncontrolled cell division and cancer?

Accepted Answer

Proto-oncogene

Question 3

Which enzyme is responsible for synthesizing the RNA primer during DNA replication?

Accepted Answer

Primase

Question 4

If a diploid organism has a genotype AaBb, what is the probability that a gamete will contain the alleles AB, assuming independent assortment?

Accepted Answer

$$P = \frac{1}{4}$$

Question 5

Which of the following best explains why linked genes do not assort independently?

Accepted Answer

They are located close together on the same chromosome.

Question 6

A woman with blood type A (genotype AO) and a man with blood type B (genotype BO) have a child. What is the probability that the child will have blood type O?

Accepted Answer

$$P = \frac{1}{4}$$

Question 7

Which process increases genetic variation during meiosis?

Accepted Answer

Crossing over

Question 8

A man with hemophilia (an X-linked recessive disorder) and a woman who is a carrier for hemophilia have a son. What is the probability that the son will have hemophilia?

Accepted Answer

$$P = \frac{1}{2}$$

Question 9

Which of the following is a consequence of a frameshift mutation?

Accepted Answer

The reading frame of the gene is altered, potentially changing every amino acid downstream.

Question 10

In a dihybrid cross between two heterozygotes (AaBb x AaBb), what is the expected phenotypic ratio of the offspring, assuming independent assortment?

Accepted Answer

9:3:3:1

Question 11

Which of the following best describes the function of tRNA during translation?

Accepted Answer

tRNA carries amino acids to the ribosome and matches them to the coded mRNA message.

Question 12

A geneticist is studying a population in Hardy-Weinberg equilibrium. If the frequency of the recessive allele ($$q) is 0.3$$, what is the expected frequency of heterozygotes?

Accepted Answer

$$2pq = 2 	imes 0.7 	imes 0.3 = 0.42$$

Question 13

Which of the following is NOT a component of a nucleotide?

Accepted Answer

Amino acid

Question 14

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

Ligase

Question 15

A woman who is heterozygous for a recessive genetic disorder marries a man who is homozygous dominant. What is the probability that their child will be affected by the disorder?

Accepted Answer

$$P = 0$$

Question 16

Which of the following best explains the phenomenon of codominance?

Accepted Answer

Both alleles are expressed equally in the phenotype.

Question 17

Which of the following is a real-world example of pleiotropy?

Accepted Answer

Sickle cell anemia, where a single gene affects multiple traits such as red blood cell shape, anemia, and resistance to malaria.

Question 18

Which of the following is the correct sequence of events in gene expression?

Accepted Answer

Transcription → Translation

Question 19

A patient is diagnosed with a mitochondrial disorder. Which parent is most likely to have passed on the disorder?

Accepted Answer

Mother

Question 20

Which of the following best describes the function of a promoter in gene regulation?

Accepted Answer

It binds RNA polymerase to initiate transcription.

Comprehensive Study Notes: Molecular Basis of Heredity, DNA Structure, and Replication

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