When cells are grown in a laboratory, which of the following is a factor that can stop normal cells from dividing?
a cut in the skin
contact with other cells
growth factors
injection of cyclin
In eukaryotic cells, the timing of the cell cycle is regulated by
cyclins
centrioles
spindle fibers
the nuclear envelope
Cyclins are a family of closely related proteins that
produce p53.
cause cancer.
work to heal wounds.
regulate the cell cycle.
Which of the following are external regulators of the cell cycle?
cancer cells
mitotic spindles
Cancer is a disorder in which some cells have lost the ability to control their
surface area
size
growth rate
Cancer cells form masses of cells called
tumors
p53
A cell with a defective p53 gene is likely to
generate hormones that combat tumors.
stop responding to growth regulators.
produce cells without a defective p53 gene.
stop dividing to produce daughter cells.
During early development, all cells in the embryo of a multicellular organism are identical. Later on in development, the cells will become specialized through a process called
differentiation
cytokinesis
apoptosis
interphase
Why are stem cells important?
They have the potential to undergo cell division.
They have specialized DNA.
They have the potential to develop into other cell types.
They are incapable of becoming cancer cells.
Which of the following is a possible future benefit of stem cell research?
increasing a person’s intelligence quotient
generating embryos from nonliving tissue
developing a vaccine for cancer
reversing damage from a heart attack
Nerve cells are cells that have not yet undergone differentiation.
Stem cells taken from embryos are totipotent.
During normal development, the cells between toes and fingers die by , a process of programmed cell death.
Harvesting stem cells from a willing donor is not as controversial as harvesting techniques that involve the destruction of an embryo.
Which diagram represents cancer?
A
B
Which diagram has a defected p53 gene?
How can the cancer cells be treated?
Chemotherapy
Radiation
Surgically removing the tumor
All of the above
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