Question 1

Which experiment provided the first direct evidence that DNA, and not protein, is the genetic material responsible for heredity in viruses?

Accepted Answer

Alfred Hershey and Martha Chase's bacteriophage experiment using radioactive isotopes

Question 2

Given a DNA strand with the sequence 5'-ATGCCGTA-3', what is the complementary DNA strand?

Accepted Answer

3'-TACGGCAT-5'

Question 3

If a DNA sample contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

$$20\%$$

Question 4

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 5

Which of the following best describes the process of 'semi-conservative replication'?

Accepted Answer

Each new DNA molecule consists of one parental and one newly synthesized strand

Question 6

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

Accepted Answer

It is redundant, with some amino acids specified by more than one codon

Question 7

A mutation changes the codon UAU (tyrosine) to UAA (stop codon). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 8

Which molecule contains an anticodon and is responsible for bringing amino acids to the ribosome during translation?

Accepted Answer

tRNA (transfer RNA)

Question 9

Which of the following best describes the role of restriction enzymes in gene cloning?

Accepted Answer

They cut DNA at specific sequences, creating sticky or blunt ends

Question 10

In gel electrophoresis, where do the shortest DNA fragments migrate?

Accepted Answer

They migrate farthest toward the positive electrode

Question 11

Which of the following is a function of adding a 5' cap and a poly-A tail to eukaryotic mRNA?

Accepted Answer

To facilitate export from the nucleus and protect mRNA from degradation

Question 12

Which process involves the uptake of naked DNA from the environment by a bacterial cell?

Accepted Answer

Transformation

Question 13

What is the primary function of tumor-suppressor genes?

Accepted Answer

To repair DNA and inhibit uncontrolled cell growth

Question 14

Which of the following best explains why cancer is more common in elderly populations?

Accepted Answer

Older individuals have more exposure to mutagens over time, increasing the chance of accumulating multiple mutations

Question 15

Which of the following describes the main advantage of using mammalian cells to produce a human protein, such as insulin, compared to using bacteria?

Accepted Answer

Mammalian cells can perform complex post-translational modifications

Question 16

Which of the following chemical modifications is most likely to decrease gene expression by condensing chromatin?

Accepted Answer

Addition of methyl groups to DNA

Question 17

A scientist wants to amplify a specific DNA sequence from a small blood sample. Which technique should she use?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 18

Which of the following best describes a transgenic organism?

Accepted Answer

An organism that contains DNA from another species

Question 19

Which of the following is a real-world application of DNA profiling?

Accepted Answer

Identifying individuals in forensic investigations

Question 20

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

Accepted Answer

Most of the human genome is composed of non-coding DNA, such as repetitive sequences and transposable elements

Comprehensive Study Guide for Biology 1406: DNA, Gene Expression, Viruses, Cancer, and Biotechnology

Study Guide - Practice Questions