Download Ch 3 White Board Questions on The Cell

Questions Chapter 3
1. The smallest unit capable of like itself is
a. the organ
b. the organelle
c. the tissue
d. the cell
e. the nucleus
2. The major types of lipid found in the plasma membranes are (2):
a. cholesterol
b. neutral fats
c. phospholipids
d. fat-soluble vitamins
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
4. A person drinks a six pack of coca cola and has to make several trips to the
bathroom. This increase in urination reflects an increase in what process
occurring in the kidneys?
a. diffusion
b. osmosis
c. solute – pumping
d. filtration
5. The term used to describe the type of solution in which cells will lose water to
their environment is
a. isotonic
b. hypertonic
c. hypotonic
d. catatonic
6. Osmosis always involves
a. a differentially permeable membrane
b. a difference in solvent concentration
c. diffusion
d. active transport
e. a,b,c
7. A physiologist observes that the concentration of sodium inside a cell is decidedly
lower than that outside the cell. Yet sodium does diffuse easily across the plasma
membrane of such cells when they are dead, but not when they are alive. Which
of the following terms applies best to this cellular function that is lacking in dead
cells?
a. osmosis
b. diffusion
c. active transport
d. dialysis
8. The solute-pumping variety of active transport is accomplished by
a. exocytosis
b. phagocytosis
c. electrical forces in the cell membrane
d. conformational-positional changes in carrier molecules in the plasma
membrane
9. The endocytotic process in which a sampling of particular matter is engulfed and
brought into the cell is called:
a. phagocytosis
b. bulk-phase endocytosis
c. exocytosis
10. the nuclear substance composed of histone proteins and DNA is
a. chromatin
b. the nucleolus
c. nuclear sap
d. nuclear pores
11. The information sequence that determines the nature of a protein is the
a. nucleotide
b. gene
c. triplet
d. codon
12. Mutations may be caused by
a. X-rays
b. Certain chemicals
c. Radiation from ionizing radioisotopes
d. All of the above
13. 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
14. Final preparations for cell division are made during the life cycle subphase called:
a.
b.
c.
d.
G1
G2
M
S
15. The RNA synthesized on one of the DNA strands is
a. mRNA
b. tRNA
c. rRNA
d. all of these
16. The RNA species that carries the coded message, specifying the sequence of
amino acids in the protein to be made, from the nucleus to the cytoplasm is
a. mRNA
b. tRNA
c. rRNA
d. all of these
17. 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
18. 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
19. A. Name the organelle that is the major site of ATP synthesis. B. Name the
three organelles involved in protein synthesis or modification of both. C. Name
the two organelles that contain enzymes and describe their relative functions.
20. Explain why mitosis can be thought of a s cellular immortality.
21. If a cell loses or ejects its nucleus, what is its fate and why?
22. The external faces of some of the proteins in the plasma membrane have
carbohydrate groups attached to them. What role do such “sugar coated” proteins
play in the life of the cell?
23. Cells are living units. However, three classes of nonliving substances are found
outside of the cells. What are these classes and functional roles do they play?
24. Comment on the role of the sodium-potassium pump in maintaining a cell’s
resting membrane potential.
25. Differentiate clearly between primary and secondary active transport processes.
Critical Thinking
1. Explain why limp celery becomes crisp and the skin of your fingertips wrinkles
when place in tap water,
2. 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.
3. Two examples of chemotherapeutic drugs and their cellular actions are listed
below. Explain why each drug culd be fatal to the cell.
a. Vincristine: Damages the mitotic spindle
b. Adriamycin: Binds to DNA and blocks mRNA synthesis
4. The normal function of one tumor-suppressor gene si to prevent cells with
damaged chromosomes and DNA from “progressing from G1 to S”, whereas
another tumor-suppressor gene prevents “passage from G2 to M”. When these
tumor-suppressor genes fail to work, cancer can result. Explain what the phrases
in quotations mean.
5. 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?
6. Dynein is missing from the cilia and flagella if individuals with a specific
inherited disorder. These individuals have severe respiratory problems and, if
males, are sterile. What is the structural connection between these two
symptoms?
7. Explain why alcoholics are likely to have much more smooth ER than teetotalers.