Question 1

Which of the following best describes the function of the nucleolus within the nucleus?

Accepted Answer

It is responsible for synthesizing ribosomal RNA (rRNA) and assembling ribosomal subunits.

Question 2

A muscle cell contains multiple nuclei. What is the primary reason for this cellular feature?

Accepted Answer

To increase the rate of protein synthesis required for muscle contraction.

Question 3

Which structure is directly responsible for determining which proteins a cell will produce?

Accepted Answer

The nucleus by selectively expressing sets of genes

Question 4

What is the correct composition of chromatin in the nucleus?

Accepted Answer

30% DNA, 60% histone protein, 10% RNA

Question 5

During mitosis, sister chromatids are joined at which specific region?

Accepted Answer

Centromere

Question 6

Which of the following statements about the nuclear envelope is TRUE?

Accepted Answer

It is continuous with the endoplasmic reticulum.

Question 7

Which of the following is a correct pairing of nitrogenous bases in DNA?

Accepted Answer

Cytosine pairs with Guanine

Question 8

What type of bond connects nucleotides together in the backbone of DNA and RNA?

Accepted Answer

Phosphodiester bond

Question 9

Which of the following is TRUE regarding the orientation of DNA strands?

Accepted Answer

The strands run in opposite directions (antiparallel).

Question 10

Given the DNA sequence 5'-AGCTTTCG-3', what is the complementary RNA sequence produced during transcription?

Accepted Answer

3'-UCGAAAGC-5'

Question 11

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

Accepted Answer

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

Question 12

Which type of RNA carries genetic information from the nucleus to the ribosome?

Accepted Answer

Messenger RNA (mRNA)

Question 13

A gene is defined as:

Accepted Answer

A sequence of DNA that encodes for a sequence of RNA that plays a role in protein production.

Question 14

If a human cell contains 46 chromosomes, how many genes does the human genome approximately encode?

Accepted Answer

About 20,000-25,000 genes

Question 15

Which of the following codons signals the start of translation in protein synthesis?

Accepted Answer

$$\mathrm{AUG}$$

Question 16

Which of the following statements about the human genome is correct?

Accepted Answer

Only about 2% of the genome are genes; the rest is structural, regulatory, or non-coding.

Question 17

Which of the following best explains why red blood cells lack nuclei?

Accepted Answer

To maximize space for hemoglobin and increase oxygen transport efficiency.

Question 18

Which of the following is a function of microRNAs?

Accepted Answer

Gene regulatory and defense functions.

Question 19

Which of the following is TRUE about the structure of DNA in cells?

Accepted Answer

DNA forms a double helix stabilized by hydrogen bonds between bases.

Question 20

A mutation changes the DNA sequence from 5'-AUGCUGGUCAAAUGA-3' to 5'-AUGCUGGUCAAUUGA-3'. What is the most likely effect on the resulting protein?

Accepted Answer

The protein will be truncated due to a premature stop codon.

Chapter three pt. 3

Study Guide - Practice Questions