BBB for Exam 4

Question 1

If a cell has 46 chromosomes at the beginning of the cell cycle, then how many sister chromatids does the cell contain during metaphase?

a. 23 chromatids
b. 46 chromatids
c. 92 chromatids
d. none of the above

Answer 1

92 chromatids

Question 2

Enzymes and energy are required for the synthesis of DNA and RNA. Which enzyme is correctly linked with its function?

A. Topoisomerase ensures that the transcription machinery starts with the codon AUG
B. DNA ligase connects DNA fragments together into a single continuous strand
C. Helicase relieves the tension due to supercoiling ahead of the replication fork
D. DNA polymerase III helps regulate the binding of mRNA to the ribosome
E. RNA polymerase synthesizes protein using mRNA as the template

Answer 2

DNA ligase connects DNA fragments together into a single continuous strand

Question 3

What is required for translation to terminate?

A. Recognition of stop codon and entry of release factor into the ribosome
B. Ribosome reads the termination sequence in the DNA sequence of the gene and disassembles
C. Binding of proteins to the origin of replication that leads to release of the ribosome’s subunits
D. Recruitment of the release factor to the TATA box in the termination sequence during translation.

Answer 3

Recognition of stop codon and entry of release factor into the ribosome

Question 4

After eukaryotic transcription takes place, the mRNA needs to be processed. Certain sections of the mRNA transcript are removed, and the remaining sections are spliced together for the final functional molecule. What is present in the mature mRNA transcript after processing?

A. Genes
B. Loci
C. Introns
D. Anticodons
E. Exons

Answer 4

Exons

Question 5

Why are RNA primers necessary for DNA replication?

Answer 5

RNA offers a free 3’ end (hydroxyl group) for initiation of DNA polymerization