Question 1

Which of the following best describes the central dogma of molecular biology as illustrated in the first image?

Accepted Answer

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

Question 2

In the process of DNA replication shown in the third image, what does 'semiconservative' replication mean?

Accepted Answer

Each new DNA molecule consists of one original strand and one new strand.

Question 3

Which base pairs with adenine in DNA, as shown in the second image?

Accepted Answer

Thymine

Question 4

A mutation replaces thymine with bromouracil in a growing E. coli culture. Where would you expect to find bromouracil?

Accepted Answer

Only in newly replicated DNA

Question 5

Which of the following is a distinguishing feature of eukaryotic DNA organization, as shown in the fourth image?

Accepted Answer

DNA is linear and wrapped around histones to form nucleosomes.

Question 6

Which structure is unique to prokaryotic cells, as shown in the fifth image?

Accepted Answer

Nucleoid

Question 7

In prokaryotic DNA replication (sixth image), what is the significance of the origin of replication?

Accepted Answer

It is the site where DNA replication is initiated.

Question 8

Which enzyme is responsible for synthesizing RNA from a DNA template during transcription, as shown in the seventh image?

Accepted Answer

RNA polymerase

Question 9

In eukaryotic cells, what is the purpose of mRNA processing steps such as capping, polyadenylation, and splicing (eighth image)?

Accepted Answer

To prepare mRNA for translation by removing introns and adding protective modifications

Question 10

Which RNA molecule carries amino acids to the ribosome during translation, as shown in the ninth image?

Accepted Answer

tRNA

Question 11

Which of the following best describes the function of rRNA in the ribosome (tenth image)?

Accepted Answer

It forms the structural and catalytic core of the ribosome.

Question 12

What is the correct order of the ribosomal sites through which tRNA moves during translation (eleventh image)?

Accepted Answer

A, P, E

Question 13

If an organism's DNA is 60% G + C, what percentage of its DNA is A + T?

Accepted Answer

$$40\%$$

Question 14

Which of the following statements about plasmids is correct?

Accepted Answer

Plasmids are small, circular DNA molecules that often carry non-essential genes, such as antibiotic resistance genes.

Question 15

What is the difference between a codon and an anticodon?

Accepted Answer

A codon is a three-nucleotide sequence on mRNA, while an anticodon is a complementary sequence on tRNA.

Question 16

Why does the insertion of three bases in DNA have a different effect than the insertion of one base?

Accepted Answer

Insertion of one base causes a frameshift mutation, while insertion of three bases adds or removes an amino acid without shifting the reading frame.

Question 17

During translation, which molecule provides the energy required for peptide bond formation?

Accepted Answer

GTP

Question 18

Which of the following best explains why prokaryotic transcription and translation can occur simultaneously?

Accepted Answer

Prokaryotes lack a nuclear envelope, allowing ribosomes to access mRNA as it is being transcribed.

Question 19

Which of the following is NOT a step in eukaryotic mRNA processing?

Accepted Answer

Removal of exons

Microbial Genetics: Structure, Function, and Molecular Processes

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