BIO 101 Exam Questions and Answers | Graded A+ | Professor Verified |
1. List the stages of interphase. -----Correct Answer----G1 - before DNA
... [Show More] replication,
cell grows in size, increases number of organelles, accumulated materials for
DNA synthesis
S - DNA synthesis occurs and two identical DNA double helix molecules (chromatids)
result
G2 - from completion of DNA replication to the onset of mitosis, cell synthesizes the
proteins that will assist cell division
2. List the checkpoints that regulate the progression of cells through the cell cycle. -
----Correct Answer----G2 Checkpoint (end of G2 before mitosis) - Mitosis will
occur if the DNA has replicated properly, Apoptosis will occur if the DNA is
damaged and cannot be replicated
M Checkpoint (between metaphase and anaphase) - spindle assembly checkpoint,
mitosis will not continue if chromosomes are not properly aligned
G1 Checkpoint (main checkpoint in G1 growth phase of the interphase) - if DNA is
damaged, apoptosis occurs, otherwise the cell is committed to divide when growth
signals are present and nutrients are available
3. Explain the mechanism within the G1, cell cycle checkpoint that evaluate growth
signals, determine nutrient availability, and assess DNA integrity. -----Correct
Answer----Failure to meet any one of these criteria results in cell's halting the cell
cycle and entering G0 stage, or undergoing apoptosis if the problems are severe.
(1) EVALUATE GROWTH SIGNALS - CDK aids in phosphorylating RB protein to
release E2F, which binds to the DNA molecule and the cell cycle continues (2)
DETERMINE NUTRIENT AVAILABILITY - starving cells enter G0, when nutrients
are present "evaluate growth signals" occurs (3) ASSESS DNA INTEGRITY - in
response to DNA damage, CDK phophorylates p53 protein which binds to DNA,
activating certain genes and DNA repair proteins are produced. Works with other
two mechanisms to complete G1. Apoptosis occurs if the DNA damage cannot
be repaired.
4. An orderly set of stages that takes place between the time a eukaryotic cell
divides and the time the resulting daughter cells also divide. -----Correct Answer--
--cell cycle
5. What are the two portions of the cell cycle? -----Correct Answer----(1) interphase
(2) mytotic stage
6. The time a eukaryotic cell performs its usual functions and when preparations are
being made for mitosis. -----Correct Answer----interphase [Show Less]