Question 1

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

Accepted Answer

Hershey-Chase experiment

Question 2

During DNA replication, which enzyme is responsible for synthesizing the new DNA strand by adding nucleotides to the 3' end?

Accepted Answer

DNA polymerase

Question 3

A cell is observed to have 46 chromosomes at the start of mitosis. After cytokinesis, how many chromosomes will each daughter cell contain?

Accepted Answer

46

Question 4

Which of the following best describes the law of independent assortment?

Accepted Answer

Alleles for different genes segregate independently during gamete formation.

Question 5

What is the function of telomerase in eukaryotic cells?

Accepted Answer

It adds repetitive sequences to the ends of chromosomes to prevent shortening.

Question 6

Which human aneuploidy is survivable and commonly observed in live births?

Accepted Answer

Trisomy 21 (Down syndrome)

Question 7

A scientist uses PCR to amplify a segment of DNA. Which of the following is NOT required for the reaction?

Accepted Answer

Ribosomes

Question 8

Which process involves the removal of introns from pre-mRNA in eukaryotes?

Accepted Answer

Splicing by the spliceosome

Question 9

A mutation changes a codon from $$	ext{UAC} ($$tyrosine) to $$	ext{UAA} ($$stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 10

Which of the following best explains the Meselson-Stahl experiment's contribution to our understanding of DNA replication?

Accepted Answer

It demonstrated that DNA replication is semiconservative.

Question 11

Which of the following is a function of the nucleolus?

Accepted Answer

Ribosomal RNA synthesis

Question 12

During meiosis, crossing over occurs at which structure?

Accepted Answer

Chiasma

Question 13

Which of the following best describes a nucleosome?

Accepted Answer

A segment of DNA wrapped around a core of histone proteins

Question 14

Which process is responsible for the separation of sister chromatids during mitosis?

Accepted Answer

Anaphase

Question 15

What is the role of topoisomerase during DNA replication?

Accepted Answer

It relieves supercoiling ahead of the replication fork.

Question 16

Which of the following is true about microsatellites?

Accepted Answer

They are short, repetitive sequences found throughout the genome.

Question 17

Which modification is added to the 5' end of eukaryotic mRNA during processing?

Accepted Answer

5' cap (7-methylguanosine)

Question 18

A diploid organism has a genotype $$AaBb$$ for two genes. If these genes assort independently, what is the expected ratio of gametes produced?

Accepted Answer

$$1:1:1:1$$ for AB, Ab, aB, ab

Question 19

Which of the following is a real-world application of Sanger dideoxy sequencing?

Accepted Answer

Identifying mutations in a patient's BRCA1 gene for cancer risk assessment

Question 20

Which process allows a single gene to produce multiple different mRNA transcripts in eukaryotes?

Accepted Answer

Alternative splicing

Comprehensive Study Guide: Key Concepts in Cell Biology

Study Guide - Practice Questions