ESSENTIAL CELL BIOLOGY CHAPTER
#18 EXAM QUESTIONS WITH CORRECT
ANSWERS
G1 cyclin - ANSWER-Regulatory protein that helps drive a cell through the first gap
phase of the cell cycle and toward S phase.
G1-Cdk - ANSWER-Protein complex whose activity drives the cell through the first gap
phase of the cell cycle; consists of a G1 cyclin plus a cyclin-dependent protein kinase
(Cdk).
anaphase-promoting complex (APC) - ANSWER-A protein complex that triggers the
separation of sister chromatids and orchestrates the carefully timed destruction of
proteins that control progresses through the cell cycle; the complex catalyzes the
ubiquitylation of its targets.
Cdk inhibitor protein - ANSWER-Regulatory protein that blocks the assembly or activity
of cyclin-Cdk complexes, delaying progression primarily through the G1 and S phases
of the cell cycle.
p53 - ANSWER-Transcription regulator that controls the cell's response to DNA
damage, preventing the cell from entering S phase until the damage has been repaired
or inducing the cell to commit suicide if the damage is too extensive; mutations in the
gene encoding this protein are found in many human cancers.
condensin - ANSWER-Protein complex that helps configure duplicated chromosomes
for segregation by making them more compact.
chromosome condensation - ANSWER-Process by which a duplicated chromosome
becomes packed into a more compact structure prior to cell division.
sister chromatid - ANSWER-Copy of a chromosome, produced by DNA replication, that
remains bound tot he other copy.
cohesin - ANSWER-Protein complex that holds sister chromatids together after DNA
has been replicated in the cell cycle.
mitosis - ANSWER-Division of the nucleus of a eukaryotic cell.
centrosome - ANSWER-Microtubule-organizing center that sits near the nucleus in an
animal cell; during the cell cycle, this structure duplicates to form the two poles of the
mitotic spindle.
#18 EXAM QUESTIONS WITH CORRECT
ANSWERS
G1 cyclin - ANSWER-Regulatory protein that helps drive a cell through the first gap
phase of the cell cycle and toward S phase.
G1-Cdk - ANSWER-Protein complex whose activity drives the cell through the first gap
phase of the cell cycle; consists of a G1 cyclin plus a cyclin-dependent protein kinase
(Cdk).
anaphase-promoting complex (APC) - ANSWER-A protein complex that triggers the
separation of sister chromatids and orchestrates the carefully timed destruction of
proteins that control progresses through the cell cycle; the complex catalyzes the
ubiquitylation of its targets.
Cdk inhibitor protein - ANSWER-Regulatory protein that blocks the assembly or activity
of cyclin-Cdk complexes, delaying progression primarily through the G1 and S phases
of the cell cycle.
p53 - ANSWER-Transcription regulator that controls the cell's response to DNA
damage, preventing the cell from entering S phase until the damage has been repaired
or inducing the cell to commit suicide if the damage is too extensive; mutations in the
gene encoding this protein are found in many human cancers.
condensin - ANSWER-Protein complex that helps configure duplicated chromosomes
for segregation by making them more compact.
chromosome condensation - ANSWER-Process by which a duplicated chromosome
becomes packed into a more compact structure prior to cell division.
sister chromatid - ANSWER-Copy of a chromosome, produced by DNA replication, that
remains bound tot he other copy.
cohesin - ANSWER-Protein complex that holds sister chromatids together after DNA
has been replicated in the cell cycle.
mitosis - ANSWER-Division of the nucleus of a eukaryotic cell.
centrosome - ANSWER-Microtubule-organizing center that sits near the nucleus in an
animal cell; during the cell cycle, this structure duplicates to form the two poles of the
mitotic spindle.
