Question 1

Which experiment provided the most direct evidence that DNA, and not protein, is the hereditary material in cells?

Accepted Answer

Avery, McCarty, and MacLeod's transformation experiment

Question 2

Phoebus Levene discovered that DNA was composed of which four units (nucleotides)?

Accepted Answer

Phosphate, deoxyribose sugar, adenine, thymine, guanine, cytosine

Question 3

In the Meselson-Stahl experiment, which model of DNA replication was supported by the results?

Accepted Answer

Semi-conservative model

Question 4

Which enzyme is responsible for synthesizing the new DNA strand during replication in prokaryotes?

Accepted Answer

DNA polymerase III

Question 5

During DNA replication, what is the role of Okazaki fragments?

Accepted Answer

They are short DNA segments synthesized on the lagging strand.

Question 6

Which process describes the conversion of DNA to RNA?

Accepted Answer

Transcription

Question 7

What is the function of the poly-A tail added to eukaryotic mRNA?

Accepted Answer

It protects mRNA from degradation and helps with export from the nucleus.

Question 8

Which of the following best describes the Central Dogma of molecular biology?

Accepted Answer

DNA is transcribed to RNA, which is translated to protein.

Question 9

Which mutation type results in a premature stop codon, potentially truncating the protein?

Accepted Answer

Nonsense mutation

Question 10

In eukaryotes, which structure is responsible for removing introns from pre-mRNA?

Accepted Answer

Spliceosome

Question 11

Which of the following is TRUE about telomeres?

Accepted Answer

They are repetitive sequences at the ends of eukaryotic chromosomes that protect genetic information.

Question 12

Which enzyme is responsible for adding complementary RNA nucleotides during transcription?

Accepted Answer

RNA polymerase

Question 13

What is the function of the promoter region in gene expression?

Accepted Answer

It is the DNA sequence where RNA polymerase binds to initiate transcription.

Question 14

Which of the following best describes the Law of Segregation in Mendelian genetics?

Accepted Answer

Each individual has two alleles for each gene, which separate during gamete formation.

Question 15

A cross between two heterozygous individuals (Aa x Aa) for a single gene will result in what genotypic ratio in the offspring?

Accepted Answer

$$1:2:1$$

Question 16

Which process occurs during meiosis but not mitosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 17

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

Accepted Answer

It alters the reading frame, potentially changing every amino acid downstream.

Question 18

In a dihybrid cross between two individuals heterozygous for both traits (AaBb x AaBb), what is the expected phenotypic ratio in the offspring?

Accepted Answer

$$9:3:3:1$$

Question 19

Which of the following statements about operons is TRUE?

Accepted Answer

An operon contains genes related to the same biochemical pathway and is regulated together.

Question 20

Which of the following best describes incomplete dominance?

Accepted Answer

The phenotype of the heterozygote is intermediate between the two homozygotes.

Study Guide: Molecular Genetics, DNA Replication, Gene Expression, and Cell Division

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