Chapter 12: Mitosis and the Cell Cycle Flashcards
The enzyme that is responsible for the copying of the ends of chromosomes
telomerase
The total set of all the genetic material of an organism
Genome
The stage where microtubules align the sister chromatids on the metaphase plate
Metaphase
A portion of the cell cycle responsible for diving the duplicated DNA into two identical cells
Mitotic
Make up the microtubule-organizing centers called centrosomes
Centrioles
Name for identically copied chromosomes
Sister
The stage when kinetochore microtubules attach to the sister chromatids
Prometaphase
Pro-oncogene that turns on cyclins and other genes to prepare for cell division
MYC
DNA + histones
Chromatin
Monomers that makeup microtubules
Tubulin
Proteing that turns a gene off is known as a transcription ______.
Supressor
Proteins that package DNA in eukaryotes
Histones
Refers to cancers ability to by-pass the cell cycle to continue to grow
Tumorgenesis
Refers to cancers ability to spread to other tissues
Metastasis
Genes that tell a cell to continue to divide
Protooncogene
Chemical factors (besides Cdks) that are sometimes necessary for the progression of the cell cycle
Growth factors
Area along the metaphase plate where a new cell wall is formed
Cell plate
Stage where sister chromatids separate and more to opposite poles
Anaphase
Tomor suppressor gene that prevents the cell from dividing before its DNA can be repaired (part of G2 checkpoint)
P53
The mitotic structure that is responsible for physically driving mitosis
Spindle
Type of mutation that involves only one nucleotide of DNA
Point
The area along the metaphase plate that constricted during cytokinesis
Cleavage furrow
Protein that turns a particular gene on
Transcription factor
Motor proteins, like those found in in muscle cells, that are responsible for cytokinesis
Myosin
A physical factor that can influence the cell cycle
Density
Accessory proteins to special kinases are involved in the cell cycle that activates the kinase. Levels fluctuate during the cell cycle
Cyclins
Refers to cancer’s ability to recruit new blood vessels
Angiogenesis
Monomers that make up microfilamenets
Actin
Phase of the cell cycle when DNA is duplicated
S phase
Cyclin (cyclin B) + kinase (cdc2) are directly responsible for the progression of the mitosis phase of the cell cycle
MPF
The MPF protein complex turns itself off by
activating the anaphase-promoting complex
The lettered circle in Figure 12.1 shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is gray. The chromosomes in the unlettered circle have not yet been replicated. Choose the correct chromosomal conditions for the following stages.
What is the correct chromosomal condition at the prometaphase of mitosis?
B
Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?
CDK
Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA?
G2
For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable?
It interferes with rapidly dividing cells
Which of the following describe(s) cyclin-dependent kinase (Cdk)?
Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other proteins.
A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G2?
16; 16
The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma.
Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that
gamma contains more DNA than beta.
If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested?
metaphase
The MPF protein complex turns itself off by
activating a process that destroys cyclin components.
Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
Centrosome
Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis?
The chromosomes are “reeled in” by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules
Movement of the chromosomes during anaphase would be most affected by a drug that
Prevents shortening of microtubules
The centromere is a region in which
Chromatids remain attached to one another until anaphase.
The lettered circle in Figure 12.1 shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is gray. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages.
What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis?
E
Why do neurons and some other specialized cells divide infrequently?
They have been shunted into G0.
For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable?
It interferes with rapidly dividing cells.
The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma.
The best conclusion concerning delta is that the cells
are actually in the G0 phase
All cell cycle checkpoints are similar in which way?
They activate or inactivate other proteins.
The MPF protein complex turns itself off by
activating a process that destroys cyclin components.
