Question 1

Which of the following is NOT a requirement for a molecule to serve as genetic material, according to early geneticists?

Accepted Answer

It must be able to catalyze metabolic reactions.

Question 2

Why did early scientists believe proteins, rather than DNA, were the genetic material?

Accepted Answer

Proteins have 20 different amino acids, allowing for more variability than DNA's four nucleotides.

Question 3

Rosalind Franklin's X-ray diffraction images of DNA provided evidence for which structural feature of DNA?

Accepted Answer

The double helix shape of DNA

Question 4

Which of the following statements about complementary base pairing in DNA is correct?

Accepted Answer

Adenine (A) always pairs with Thymine (T), and Guanine (G) always pairs with Cytosine (C).

Question 5

During DNA replication, which enzyme is responsible for unwinding the double helix?

Accepted Answer

DNA helicase

Question 6

In eukaryotic DNA replication, what is the function of single-stranded binding proteins (SSBs)?

Accepted Answer

They prevent the separated DNA strands from re-annealing.

Question 7

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

Accepted Answer

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

Question 8

A mutation occurs during DNA replication, resulting in a single base substitution. Which property of DNA allows for the possibility of this mutation being passed to future generations?

Accepted Answer

DNA can undergo mutations that are heritable.

Question 9

Which of the following is a key difference between prokaryotic and eukaryotic DNA replication?

Accepted Answer

Prokaryotic DNA replication starts at a single origin and proceeds in both directions around a circular chromosome.

Question 10

During DNA replication, the lagging strand is synthesized in short fragments known as:

Accepted Answer

Okazaki fragments

Question 11

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

Accepted Answer

DNA ligase

Question 12

If a DNA template strand has the sequence $$5'	ext{-}ATGCGT-3'$$, what will be the sequence of the complementary daughter strand (written 5' to 3')?

Accepted Answer

$$5'	ext{-}ACGCAT-3'$$

Question 13

Which of the following statements about the flow of genetic information in a cell is correct?

Accepted Answer

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

Question 14

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

Accepted Answer

DNA contains uracil, while RNA contains thymine.

Question 15

A codon is best described as:

Accepted Answer

A sequence of three RNA nucleotides that codes for a specific amino acid.

Question 16

Which codon always signals the start of translation and codes for methionine?

Accepted Answer

$$	ext{AUG}$$

Question 17

Which of the following best explains why the genetic code is described as 'redundant but not ambiguous'?

Accepted Answer

More than one codon can code for the same amino acid, but each codon codes for only one amino acid.

Question 18

A mutation changes the codon $$	ext{GAA} to$$ $$	ext{GAG} in an $$mRNA sequence. Both codons code for glutamate. What is this type of mutation called?

Accepted Answer

Silent mutation

Question 19

Which type of RNA is responsible for bringing amino acids to the ribosome during translation?

Accepted Answer

Transfer RNA (tRNA)

Question 20

A patient has a genetic disorder caused by a single base substitution in a gene. Which process most likely failed to correct this error during DNA replication?

Accepted Answer

Proofreading by DNA polymerase

DNA Structure, Replication, and Gene Expression: Study Notes for General Biology

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