BI107 - Ch. 12
Microtubules
-Protein structures that elongate dividing cells -Protein structures that help chromosomes move to the cell's poles
If an intestinal cell in a grasshopper contains 24 chromosomes, a grasshopper sperm cell would contain __________ chromosomes.
12
If the haploid number of chromosomes for a species is 3, each dividing diploid cell will have how many total chromatids at metaphase?
12
If there are 12 chromosomes in an animal cell in the G1 stage of the cell cycle, what is the diploid number of chromosomes for this organism?
12
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. Those cells would have ____ picograms at the end of the S phase and ____ picograms at the end of G2.
16, 16
A cell with 20 chromosomes (diploid number) goes through the cell cycle. The number of chromosomes after doubling the DNA in the S phase is
20
If there are 20 centromeres in a cell, how many chromosomes are there?
20
A cell containing 92 chromatids at the start of mitosis would, at its completion, produce daughter cells containing how many chromosomes?
46
How many chromosomes will a cell have during mitotic anaphase if the diploid chromosome number is 4?
8
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain altogether?
92
Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants
A cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage
The formation of a cell plate is beginning across the middle of a cell and nuclei are reforming at opposite ends of the cell. What kind of a cell is this?
A plant cell undergoing cytokinesis
Which of the following is true about sister chromatids? A. are created when DNA is replicated. B. are attached at the centromere prior to division. C. are separated during mitosis. D. have matching copies of the chromosome's DNA.
All of the above
Which of the following organisms does NOT reproduce cells by mitosis and cytokinesis? A. cow B. bacterium C. mushroom D. cockroach E. banana tree
Bacterium
A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in a cell doubled
Between the G1 and G2 phases
Anaphase
Centromeres break up, sister chromatids are separated, and the two new chromosomes move to opposite poles of the cell
The centromere is a region in which
Chromatids are attached to one another
Metaphase
Chromosomes are arranged in the middle of the cell
Cytochalasin B is a chemical that disrupts microfilament formation. This chemical would interfere with
Cleavage furrow in animal cell division
The major proteins that control the cell cycle check points are
Cyclin and cyclin dependent kinse (cdks)
Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called
Cyclins
The S phase was measured by
Determining the start and stop of increased DNA in the cells
True or False: During the latter stages of mitotic prophase chromosomes are duplicated?
False
True or False: Each chromosome is made of two chromatids is a characteristic of telophase of mitosis?
False
True or False: The production of gametes is a function of mitotic cell division in animal?
False
True or False: The synthesis of DNA occurs during mitosis?
False
During which phase(s) of mitosis do we find chromosomes composed of two chromatids?
From G2 of interphase through metaphase
Most cells will divide if they receive the proper signal at a checkpoint in the __________ phase of the cell cycle.
G1
Cells that have stopped dividing are
In the G0 phase of the cell cycle
In some organisms such as certain fungi and algae, cells undergo mitosis repeatedly without subsequently undergoing cytokinesis. What would result from this?
Large cells containing many nuclei
If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested?
Metaphase
Metastasis is when cancerous cells
Migrate from the initial site of transformation to other organs or tissues
The kinetochores
Move along spindle microtubules during anaphase, dragging their chromosome toward one pole of the cell.
In telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in
Prophase
Start kinase
Protein complex that lifts the G1 check point
MPF
Protein complex that lifts the G2 check point
CDK
Protein that combines with cyclin to lift cell cycle check points
Cyclin
Protein that gets synthesized and degraded during the cell cycle
A benign tumor is one in which the cancerous cells
Remain confined to their original site and do not affect the organ's function
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. One nucleus had 4.5 picograms of DNA. What stage of the cell cycle was this nucleus in?
S
Which of the following phases of mitosis is essentially the opposite of prometaphase (late prophase) in terms of nuclear changes?
Telophase
Telophase
The cell is preparing for cytokinesis
How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in GI of the cell cycle?
The daughter cells have the same number of chromosomes and the same amount of DNA
The maturation promoting factor (MPF) protein gets inactivated by
The destruction of cyclin molecule
It is difficult to observe individual chromosomes with a light microscope during interphase because
They have uncoiled to form long, thin strands.
Recent research has indicated that cancer cells
Transform normal cells by altering genes involved in the control of mitosis
Prophase
Two centrioles are approaching to opposite poles of the cell
A cell that passes the G1 restriction point will most likely
Will next undergo chromosome duplication.
