Question 1

Which of the following best explains why DNA replication is described as 'semiconservative'?

Accepted Answer

Each new DNA molecule contains one original strand and one newly synthesized strand.

Question 2

A scientist isolates a nucleic acid and determines it contains ribose sugar and uracil. Which type of molecule is this most likely to be?

Accepted Answer

RNA

Question 3

Which enzyme is responsible for relieving supercoiling ahead of the replication fork during DNA replication?

Accepted Answer

Topoisomerase

Question 4

During transcription in eukaryotes, which of the following modifications is added to the 5' end of the pre-mRNA?

Accepted Answer

$$5'$$ cap

Question 5

A DNA strand has the sequence 5'-ATCGGCTA-3'. What is the complementary sequence of the other strand, written 5' to 3'?

Accepted Answer

5'-TAGCCGAT-3'

Question 6

Which of the following best describes the difference between exons and introns in eukaryotic genes?

Accepted Answer

Exons are coding sequences that remain in the final mRNA, while introns are removed during splicing.

Question 7

Which of the following statements about hydrogen bonds in DNA is correct?

Accepted Answer

Hydrogen bonds hold complementary nitrogenous bases together between the two DNA strands.

Question 8

A cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

Water will exit the cell, causing it to shrink.

Question 9

Which of the following best describes an ionic bond?

Accepted Answer

An electron is transferred from one atom to another, resulting in attraction between oppositely charged ions.

Question 10

Which process occurs in the thylakoid membranes and produces ATP and NADPH?

Accepted Answer

Light reactions of photosynthesis

Question 11

Which of the following is true about glycolysis?

Accepted Answer

It can occur with or without oxygen.

Question 12

Which enzyme is responsible for synthesizing short RNA primers during DNA replication?

Accepted Answer

Primase

Question 13

A mutation causes the loss of function of telomerase in a cell. What is the most likely consequence?

Accepted Answer

Chromosome ends will shorten with each cell division, leading to cell senescence.

Question 14

Which of the following best describes a DNA palindrome and its importance?

Accepted Answer

A sequence that reads the same on both strands in opposite directions; important for restriction enzymes.

Question 15

Which of the following chemical reactions requires an input of energy and has a positive $$\Delta G$$?

Accepted Answer

Endergonic reaction

Question 16

Which of the following is a function of single-stranded binding proteins during DNA replication?

Accepted Answer

They stabilize unwound DNA strands to prevent them from re-annealing.

Question 17

Which of the following best explains why several codons can code for the same amino acid?

Accepted Answer

The genetic code is redundant.

Question 18

Which of the following is the main enzyme responsible for synthesizing mRNA in eukaryotes?

Accepted Answer

RNA polymerase II

Question 19

A patient is found to have a mutation that prevents the removal of introns from pre-mRNA. What is the most likely effect on the protein produced?

Accepted Answer

The protein will be abnormal due to the presence of non-coding sequences.

Question 20

Which of the following best describes the role of oxygen in cellular respiration?

Accepted Answer

It acts as the final electron acceptor in the electron transport chain.

General Biology: Core Concepts and Processes Study Guide

Study Guide - Practice Questions