Question 1

During which phase of the cell cycle does DNA replication occur, and what is the significance of this process for cell division?

Accepted Answer

DNA replication occurs during the S phase, allowing each daughter cell to receive a complete set of genetic information.

Question 2

Which of the following best describes semiconservative replication of DNA?

Accepted Answer

Each new DNA molecule consists of one old strand and one new strand.

Question 3

A cell that has permanently ceased dividing is said to be in which phase?

Accepted Answer

G\_0 phase

Question 4

Which of the following cell types is LEAST likely to undergo mitosis for repair purposes?

Accepted Answer

Skeletal muscle cells

Question 5

What is the correct sequence of the four stages of mitosis?

Accepted Answer

Prophase, Metaphase, Anaphase, Telophase

Question 6

During cytokinesis, what cellular structure is responsible for forming the cleavage furrow that separates the two daughter cells?

Accepted Answer

Actin microfilaments

Question 7

Which molecule carries the genetic instructions from DNA in the nucleus to the ribosome for protein synthesis?

Accepted Answer

Messenger RNA (mRNA)

Question 8

What is the role of the spliceosome in mRNA processing?

Accepted Answer

It removes introns from pre-mRNA, leaving only exons.

Question 9

If a DNA triplet is AGT, what is the corresponding mRNA codon produced during transcription?

Accepted Answer

UCA

Question 10

Which of the following statements about the genetic code is TRUE?

Accepted Answer

There are 64 possible codons and only 20 amino acids, resulting in redundancy.

Question 11

During translation, what is the function of the tRNA anticodon?

Accepted Answer

It pairs with the mRNA codon to ensure the correct amino acid is added to the polypeptide chain.

Question 12

Which phase of translation involves the ribosome scanning the mRNA for the start codon?

Accepted Answer

Initiation

Question 13

A mutation changes the DNA triplet from GGC to GCC. What is the likely effect on the resulting protein?

Accepted Answer

The codon may still code for the same amino acid due to redundancy in the genetic code.

Question 14

Which of the following is NOT a difference between DNA and RNA?

Accepted Answer

DNA is found only in the cytoplasm, while RNA is found only in the nucleus.

Question 15

Which enzyme is responsible for adding complementary nucleotides to the growing mRNA strand during transcription?

Accepted Answer

RNA polymerase

Question 16

What is the correct order of events in the elongation phase of translation?

Accepted Answer

Codon recognition, peptide bond formation, translocation

Question 17

Which of the following codons is a stop codon in mRNA?

Accepted Answer

UAA

Question 18

If a cell fails to remove introns from its pre-mRNA, what is the most likely consequence?

Accepted Answer

The resulting protein will be nonfunctional due to incorrect amino acid sequence.

Question 19

Which process ensures that the correct amino acid is added to the growing polypeptide chain during translation?

Accepted Answer

Complementary base pairing between mRNA codon and tRNA anticodon

Question 20

A patient has a genetic disorder caused by a mutation in the spliceosome machinery. Which cellular process is most directly affected?

Accepted Answer

mRNA processing

Cell Cycle and Protein Synthesis: The Living Units

Study Guide - Practice Questions