Question 1

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

Accepted Answer

DNA → RNA → Protein

Question 2

During transcription in eukaryotic cells, where does the process primarily occur?

Accepted Answer

In the nucleus

Question 3

Which of the following statements about DNA and RNA is correct?

Accepted Answer

RNA contains ribose and uracil.

Question 4

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

Accepted Answer

The protein will have a different amino acid at this position, possibly altering its function.

Question 5

Which type of bond connects nucleotides together in a single strand of DNA?

Accepted Answer

Phosphodiester bond

Question 6

If a DNA template strand has the sequence 5'-TACGGA-3', what is the sequence of the mRNA produced during transcription?

Accepted Answer

5'-AUGCCU-3'

Question 7

Which of the following best explains why DNA strands are described as antiparallel?

Accepted Answer

The two strands run in opposite 5' to 3' directions.

Question 8

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

Accepted Answer

Adenine–Thymine

Question 9

A scientist isolates a nucleic acid with the following characteristics: single-stranded, contains uracil, and has a ribose sugar. What is the identity of this molecule?

Accepted Answer

RNA

Question 10

Which of the following best describes the role of mRNA in the process of protein synthesis?

Accepted Answer

It carries the genetic code from DNA to the ribosome.

Question 11

Which enzyme is responsible for synthesizing RNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 12

In eukaryotic cells, what is the function of the poly-A signal during transcription termination?

Accepted Answer

It signals the end of transcription and leads to mRNA cleavage.

Question 13

Which of the following best explains why a change in DNA sequence can alter phenotype?

Accepted Answer

DNA sequence determines the sequence of amino acids in proteins, which affects protein function and phenotype.

Question 14

Which of the following is a correct description of a peptide bond?

Accepted Answer

A bond between the amino group of one amino acid and the carboxyl group of another

Question 15

A patient has a genetic disorder caused by a single base substitution in a gene. Which process is most directly affected by this mutation?

Accepted Answer

Translation of mRNA into protein

Question 16

Which of the following equations correctly represents the condensation reaction that forms a phosphodiester bond between two nucleotides?

Accepted Answer

$$Nucleotide_1$$ + $$Nucleotide_2$$ \rightarrow Dinucleotide + H_2O$$

Question 17

Which of the following best describes the function of the ribosome during translation?

Accepted Answer

It catalyzes the formation of peptide bonds between amino acids.

Question 18

A DNA double helix has a high proportion of guanine and cytosine bases. Which property is most likely to be affected by this composition?

Accepted Answer

The DNA will be more stable due to more hydrogen bonds.

Question 19

Which of the following is a correct statement about the genetic code?

Accepted Answer

The genetic code is universal and redundant.

Question 20

A researcher is studying a bacterial gene and finds that transcription stops when a hairpin loop forms in the RNA. What is the most likely mechanism of transcription termination?

Accepted Answer

Intrinsic (rho-independent) termination

C4,16,17 Central Dogma of Molecular Biology: DNA, RNA, and Protein Synthesis

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