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Problem 1
The smallest unit capable of life by itself is:
a. The organ
b. The organelle
c. The tissue
d. The cell
e. The nucleus
Problem 2
The major types of lipids found in the plasma membranes are (choose two):
a. Cholesterol
b. Triglycerides
c. Phospholipids
d. Fat-soluble vitamins
Problem 3
Membrane junctions that allow nutrients or ions to flow from cell to cell are:
a. Desmosomes
b. Gap junctions
c. Tight junctions
d. All of these
Problem 4
Osmosis always involves:
a. A selectively permeable membrane
b. A difference in solute concentration
c. Diffusion
d. Active transport
e. a, b, and c
Problem 5
The endocytotic process in which a sampling of particulate matter is engulfed and brought into the cell is called:
a. Phagocytosis
b. Pinocytosis
c. Exocytosis
Problem 6
The nuclear substance composed of histone proteins and DNA is:
a. Chromatin
b. The nucleolus
c. Nucleoplasm
d. Nuclear pores
Problem 7
The information sequence that determines the nature of a protein is:
a. Nucleotide
b. Gene
c. Triplet
d. Codon
Problem 8
The phase of mitosis during which centrioles reach the poles and chromosomes attach to the spindle is
a. Anaphase
b. Metaphase
c. Prophase
d. Telophase
Problem 9
The RNA synthesized on one of the DNA strands is:
a. mRNA
b. tRNA
c. rRNA
d. all of these.
Problem 10
The RNA species that travels from the nucleus to the cytoplasm carrying the coded message specifying the sequence of amino acids in the protein to be made is
a. mRNA
b. tRNA
c. rRNA
d. all of these
Problem 11
Cells lining the trachea have whiplike motile extensions on their free surfaces. What are these extensions, what is their source, and what is their function?
Problem 12
A physiologist observes that the concentration of sodium inside a cell is decidedly lower than that outside the cell. She also observes that there is a small leakage of sodium into the cell. What cellular process prevents the sodium concentration gradient from disappearing?
a. Osmosis
b. Diffusion
c. Primary active transport
d. Secondary active transport
Problem 13
If DNA has a sequence of AAA, then a segment of mRNA synthesized on it will have a sequence of:
a. TTT
b. UUU
c. GGG
d. CCC
Problem 14
A nerve cell and a lymphocyte are presumed to differ in their:
a. Specialized structure
b. Suppressed genes and embryonic history
c. Genetic information
d. a and b, e. a and c
Problem 16
The type of fracture that occurs in osteoporosis:
Problem 17
Comment on the role of the sodium-potassium pump in maintaining a cell's resting membrane potential.
Problem 19
Two examples of chemotherapeutic drugs (drugs used to treat cancer) and their cellular actions are listed below. Explain why each drug could be fatal to a cell. • Vincristine (brand name Oncovin): damages the mitotic spindle • Doxorubicin (Adriamycin): binds to DNA and blocks mRNA synthesis
Problem 20
In their anatomy lab, many students are exposed to the chemical preservatives phenol, formaldehyde, and alcohol. Our cells break down these toxins very effectively. What cellular organelle is responsible for this?
Problem 21
Cell division typically yields two daughter cells, each with one nucleus. How is the occasional binucleate condition of liver cells explained?
Problem 22
A 'red-hot' bacterial infection of the intestinal tract irritates the intestinal cells and interferes with digestion. Such a condition is often accompanied by diarrhea, which causes loss of body water. On the basis of what you have learned about osmotic water flows, explain why diarrhea may occur.
Problem 24
Explain why alcoholics are likely to have much more smooth ER than teetotalers.
Problem 25
Fresh water is a precious natural resource in Florida and it is said that supplies are dwindling. Desalinizing (removing salt from) ocean water has been recommended as a solution to the problem. Why shouldn't we drink salt water?