Bio 111 Ch 11 Questions

Which of the steps on prokaryotic binary fission is correct?

• The cell wall material is laid down at the midpoint to separate the two daughter cells.

• DNA is replicated bidirectionally from a single point on the circular chromosome.

• All of these choices are correct.

• The two replicated chromosomes remain attached to the plasma membrane.

• The cell continues to grow outward symmetrically, separating the two chromosomes.

Muscle cells in the mammalian heart are multinucleate, meaning that multiple nuclei are present in the cytoplasm of individual large cells. Predict what is different about the cell cycle in a muscle cell.

• S phase happens twice.

• The G₁ and G₂ phases are extended.

• Cytokinesis does not occur.

• M phase is inhibited.

ATP, the ubiquitous molecule involved in providing energy for many cellular functions, is a nucleotide that includes ribose as its sugar component. ATP is also the monomer used when adding an A to the growing strand during DNA replication. How do these molecules differ?

• In DNA replication, the ribose lacks a 2' hydroxyl group.

• Both molecules have the same abbreviation, but they are not chemically related.

• In energy reactions, ATP has deoxyribose.

• In DNA replication, the ribose lacks a 3' hydroxyl group.

• In energy reactions, the ribose lacks a 3' hydroxyl group.

What would happen if telomerase stopped working in a cell in which it normally functions at high levels?

• The cell would eventually stop dividing.

• The cells would be able to divide indefinitely.

• Cancer would be the result.

• The cell would die immediately.

• None of the other answer options is correct.

A human cell with a total of 23 chromosomes is:

• aneuploid

• polyploid

• diploid

• haploid

The microtubules that form the mitotic spindle extend out from the centrosome. Where would you expect to find the plus (fast-assembling) end of a spindle microtubule?

• toward the centrosome and toward the kinetochore

• toward the centrosome and away from the kinetochore

• away from the centrosome and away from the kinetochore

• away from the centrosome and toward the kinetochore

A woman has her genome sequenced and finds that she carries a mutation in p53. will she develop cancer?

• Yes, she will certainly develop cancer given the role of p53 in the cell cycle.

• No, mutations in p53 do not contribute to cancer.

• Possibly; this mutation is likely to predispose her to developing certain types of cancer.

How would the loss of p53 activity affect the cell?

• All of these choices are correct.

• DNA damage could accumulate.

• CDK activity would not be appropriately regulated.

• The G₁/S checkpoint would not be functional.

Replication of DNA in a eukaryote occurs during which phase of the cell cycle?

• S phase

• M phase

• G₁ phase

• G₂ phase

What is the name of the enzyme that separates the two strands of DNA during replication?

• DNA polymerase

• helicase

• DNA ligase

• primase

• topoisomerase