Critical and Creative Thinking Questions
1. As you examine various cells under a microscope, you observe
one type of cell that has large amounts of rough endoplasmic
reticulum, vesicles merging with the plasma membrane, Golgi
complexes, and mitochondria. What do you think is the function
of this cell? Explain your answer, based on your observations.
2. Cells within a culture may grow and divide, but they do not
do so all at the same time (that is, their growth is not synchro-
nized). You want to study the cell cycle and require a synchro-
nous culture. A drug called colchicine blocks microtubule
formation, and its effects are reversible. How might you use
this drug to synchronize your cell culture?
3. Janet's house is being infested by soft-bodied slugs. Rather
than spray pesticide, an exterminator places rock salt around
the perimeter of the foundation. Janet notices that upon
encountering the salt, the slugs appear to shrink in size before
dying. What might the salt do to a slug's cells and tissues?
Explain your answer.
4. Chronic smokers often cough and have difficulty clearing mu-
cus from their lungs. What type of epithelium is present in the
airways, and what cell parts might be damaged, thus prevent-
ing smokers from clearing away foreign particles and mucus?
5. Manufacturers claim that a popular nutritional supplement
keeps joints healthy. The supplement contains high concen-
trations of chondroitin sulfate and glucosamine. How do you
suppose these substances might work?
What is happening in this picture?
Snake venom includes the enzym es phospholipase and hyaluroni-
dase. Major effects include red blood cell and muscle cell dam age
and disruption of blood vessel walls, which leads to bleeding, sw ell-
ing, cell death, and cardiovascular effects.
NATIONAL
GEOGRAPHIC
1.
How w ould
p h ospholipase d am age cells?
2.
H ow w ould hyaluronidase disrupt
blood vessels and cause sw elling?
What is happening in this picture? 87
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