Review Questions

Review Questions

A diploid cell has how many times the number of chromosomes as a haploid cell?
  1. four times
  2. half
  3. one-fourth
  4. twice
The first level of DNA organization in a eukaryotic cell is maintained by which molecule?
  1. cohesion
  2. condensin
  3. chromatin
  4. histone
What inherited feature, in specific combinations, determines an organism’s traits?
  1. cell membranes
  2. genes
  3. proteins
  4. RNA
What are identical copies of chromatin held together by cohesin at the centromere called?
  1. histones
  2. nucleosomes
  3. chromatin
  4. sister chromatids

Chromosomes are duplicated during what stage of the cell cycle?

  1. G1 phase
  2. prophase
  3. prometaphase
  4. S phase
Which of the following events does not occur during some stages of interphase?
  1. DNA duplication
  2. increase in cell size
  3. organelle duplication
  4. separation of sister chromatids
Attachment of the mitotic spindle fibers to the kinetochores is a characteristic of which stage of mitosis?
  1. anaphase
  2. prophase
  3. prometaphase
  4. metaphase
The fusing of Golgi vesicles at the metaphase plate of dividing plant cells forms what structure?
  1. actin ring
  2. cell plate
  3. cleavage furrow
  4. mitotic spindle

What would be the outcome of blocking S phase of interphase?

  1. The cell would enter karyokinesis.
  2. DNA replication would not occur.
  3. Centrosomes would be duplicated.
  4. The cytoskeleton would be dismantled.

At which of the cell cycle checkpoints do external forces have the greatest influence?

  1. G1 checkpoint
  2. G2 checkpoint
  3. M checkpoint
  4. G0 checkpoint
If the M checkpoint is not cleared, what stage of mitosis will be blocked?
  1. prophase
  2. prometaphase
  3. metaphase
  4. anaphase

Which protein is a positive regulator that phosphorylates other proteins when activated?

  1. p53
  2. retinoblastoma protein (Rb)
  3. cyclin
  4. cyclin-dependent kinase (Cdk)

Which negative regulatory molecule can trigger apoptosis if vital cell cycle events do not occur?

  1. p53
  2. p21
  3. retinoblastoma protein (Rb)
  4. cyclin-dependent kinase (Cdk)
What is the main prerequisite for clearance at the G 2 checkpoint?
  1. The cell has a reached a sufficient size.
  2. The cell has an adequate stockpile of nucleotides.
  3. An accurate and complete DNA replication has occurred.
  4. Proper attachment of mitotic spindle fibers to kinetochores has occurred.
What do you call changes to the order of nucleotides in a segment of DNA that codes for a protein?
  1. proto-oncogenes
  2. tumor suppressor genes
  3. gene mutations
  4. negative regulators
Human papillomavirus can cause cervical cancer. The virus encodes E6, a protein that binds p53. Based on this fact and what you know about p53, what effect do you think E6 binding has on p53 activity?
  1. E6 activates p53.
  2. E6 protects p53 from degradation.
  3. E6 mutates p53.
  4. E6 binding marks p53 for degradation.
What is a gene that codes for a positive cell cycle regulator called?
  1. kinase inhibitor
  2. oncogenes
  3. proto-oncogenes
  4. tumor suppressor genes
Which molecule is a Cdk inhibitor or is controlled by p53?
  1. anti-kinase
  2. cyclin
  3. p21
  4. Rb
Which eukaryotic cell cycle events are missing in binary fission?
  1. cell growth
  2. DNA duplication
  3. karyokinesis
  4. cytokinesis
Which of the following statements about binary fission is false?
  1. In both prokaryotic and eukaryotic cells, the outcome of cell reproduction is a pair of daughter cells, which are genetically identical to the parent cell.
  2. Karyokinesis is unnecessary in prokaryotes because there is no nucleus.
  3. Replication of the prokaryotic chromosome begins at the origin of replication and continues in both directions at once.
  4. The mitotic spindle draws the duplicated chromosomes to the opposite ends of the cell followed by formation of a septum and two daughter cells.
The formation of what structure, that will eventually form the new cell walls of the daughter cells, is directed by FtsZ?
  1. contractile ring
  2. cell plate
  3. cytoskeleton
  4. septum