Q: Which of the following best describes the flow of genetic information in a cell, according to the central dogma of molecular biology?

$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following was a primary reason early scientists believed proteins, rather than DNA, were the genetic material?

Accepted Answer

Proteins have a greater variety of building blocks (20 amino acids) compared to DNA's four nucleotides, allowing for more possible combinations.

Question 2

Which of the following is NOT a requirement for a molecule to be considered the genetic material?

Accepted Answer

It must be able to catalyze metabolic reactions.

Question 3

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

Accepted Answer

The double helix structure with repeating helical patterns.

Question 4

Which statement best describes the antiparallel nature of DNA strands?

Accepted Answer

The two strands run in opposite directions: one from $$5' to$$ $$3'$$, the other from $$3' to$$ $$5'.$$

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 replication bubbles?

Accepted Answer

They allow DNA replication to begin at multiple sites along the chromosome, speeding up the process.

Question 7

Which of the following best explains why DNA replication is described as 'semi-conservative'?

Accepted Answer

Each new DNA molecule consists of one parental (old) strand and one newly synthesized (daughter) strand.

Question 8

A mutation in the gene encoding DNA polymerase causes it to lose its proofreading ability. What is the most likely consequence?

Accepted Answer

The frequency of replication errors (mutations) will increase.

Question 9

Which of the following statements about the leading and lagging strands during DNA replication is correct?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

Question 10

Which of the following best describes the flow of genetic information in a cell, according to the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 11

Which of the following is a key structural difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar and thymine, while RNA contains ribose sugar and uracil.

Question 12

A scientist discovers a new organism whose genetic material is a single, circular DNA molecule. Which of the following is most likely true about this organism?

Accepted Answer

It is a prokaryote, and its DNA replication starts at a single origin and proceeds in both directions.

Question 13

Which of the following best describes the role of messenger RNA (mRNA) in gene expression?

Accepted Answer

It carries the genetic code from DNA in the nucleus to the ribosome for protein synthesis.

Question 14

Which of the following statements about codons is TRUE?

Accepted Answer

Each codon consists of three RNA nucleotides and specifies a single amino acid.

Question 15

A mutation changes the DNA sequence from $$	ext{TAC} to$$ $$	ext{TAA} in a $$gene. If the mRNA is transcribed, what is the likely effect on translation?

Accepted Answer

The mRNA codon will become $$	ext{UAA}$$, which is a stop codon, leading to premature termination of translation.

Question 16

Which of the following is a function of transfer RNA (tRNA) during translation?

Accepted Answer

It brings the appropriate amino acid to the ribosome based on the codon in mRNA.

Question 17

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

Accepted Answer

$$	ext{AUG}$$

Question 18

If a DNA template strand has the sequence $$5'	ext{-ATG CCG TAA-}3'$$, what will be the sequence of the mRNA transcribed from this region?

Accepted Answer

$$5'	ext{-AUG CCG UAA-}3'$$

Question 19

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.

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

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드