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

$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best explains why males are more likely than females to express recessive X-linked genetic disorders?

Accepted Answer

Males have only one X chromosome, so a single recessive allele will be expressed.

Question 2

A woman who is heterozygous for an X-linked trait and a man who does not carry the allele have a son. What is the probability that their son will express the recessive trait?

Accepted Answer

$$0.5$$

Question 3

Which chromosomal mutation is most likely to result in a gene being present in two copies on the same chromosome?

Accepted Answer

Duplication

Question 4

During DNA replication, which enzyme is responsible for joining Okazaki fragments on the lagging strand?

Accepted Answer

DNA ligase

Question 5

A scientist observes that after DNA replication, each new DNA molecule consists of one old strand and one new strand. This observation supports which model of DNA replication?

Accepted Answer

Semi-conservative

Question 6

Which of the following correctly describes the difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 7

A mutation changes a codon from UAU (tyrosine) to UAA (stop codon). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 8

Which process occurs in the nucleus and results in the production of a pre-mRNA molecule?

Accepted Answer

Transcription

Question 9

Which of the following is NOT a step in mRNA processing in eukaryotes?

Accepted Answer

Attachment of Okazaki fragments

Question 10

A population of beetles has the following genotype frequencies: $$p^2 = 0.36$, 2pq = 0.48$, q^2$ = 0.16. $$According to the Hardy-Weinberg equation, what is the frequency of the dominant allele?

Accepted Answer

$$p = 0.6$$

Question 11

Which of the following is an example of genetic drift?

Accepted Answer

A hurricane randomly kills most of a population, leaving only a few survivors.

Question 12

Which type of natural selection favors individuals with intermediate phenotypes and reduces variation?

Accepted Answer

Stabilizing selection

Question 13

Which of the following provides evidence for evolution based on similarities in bone structure among different species?

Accepted Answer

Homology

Question 14

A woman is a carrier for hemophilia (an X-linked recessive disorder), and her partner is unaffected. What is the probability that their daughter will have hemophilia?

Accepted Answer

$$0.0$$

Question 15

Which of the following best describes the role of telomeres in eukaryotic chromosomes?

Accepted Answer

They protect chromosome ends from deterioration during replication.

Question 16

If a population is in Hardy-Weinberg equilibrium, which of the following must be true?

Accepted Answer

No mutations, random mating, no natural selection, large population size, and no gene flow.

Question 17

A gene is translocated from chromosome 1 to chromosome 15. What type of chromosomal mutation is this?

Accepted Answer

Translocation

Question 18

Which of the following statements about evolution is correct?

Accepted Answer

Evolution does not create perfect organisms; it selects for traits that are good enough for survival and reproduction.

Question 19

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

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 20

A mutation causes a shift in the reading frame of the genetic code. What type of mutation is this?

Accepted Answer

Frameshift mutation

Chromosomal Inheritance, DNA Replication, Gene Expression, and Evolution: Study Notes

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