Biology Quiz

1. Which statements about modern cell theory are true?

a. Cells arise from other cells.

b. All living organisms consist of one or more cells.

c. Cells contain hereditary information that passes from one generation of cells to the next.

d. All of the above are true.

2. Which of the following is NOT true about prokaryotic cells?

a. They have a circular loop of DNA instead of multiple linear DNA molecules.

b. They are always single-celled organisms and they never contain mitochondria.

c. They all have a rigid cell wall INSTEAD of a plasma membrane.

d. They may have flagella but they never have cilia.

e. They lack a nucleus but they do have ribosomes.

3. Which of the following statements about phospholipids is FALSE?

a. A phospholipid consists of a glycerol molecule attached to two fatty acid chains.

b. Phospholipid molecules have hydrophobic and hydrophilic regions.

c. A phospholipid contains one negatively charged phosphate group.

d. Phospholipids are a principal component of the plasma membrane.

e. All of the above are true.

4. Which of the following is NOT a correct statement about passive transport across the cell membrane?

a. Passive transport increases entropy in a system.

b. Passive transport decreases free energy.

c. Diffusion across an electrochemical gradient is one form of passive transport.

d. Passive transport may involve chemical energy in the form of ATP.

e. Facilitated diffusion by transport proteins is one form of passive transport.

5. Diffusion across the cell's outer membrane:

a. is also called dynamic equilibrium.

b. occurs without the input of energy.

c. always results with the molecules moving from areas of low concentration to areas of high concentration.

d. never occurs; all molecules cross the membrane within protein carriers.

e. None of the above is correct.

6. Which of the following are not components of animal cells?

a. chloroplasts

b. endoplasmic reticulum

c. mitochondria

d. cell walls

e. Both a and d are not components of animal cells.

7. The smooth endoplasmic reticulum:

a. modifies proteins that will be shipped elsewhere in the organism.

b. processes and packages proteins, lipids, and other molecules.

c. directs cellular activity and stores hereditary information.

d. digests and recycles cellular waste products and consumed materials.

e. synthesizes lipids and detoxifies molecules.

8. The Golgi apparatus:

a. synthesizes lipids and detoxifies molecules.

b. directs cellular activity and stores hereditary information.

c. digests and recycles cellular waste products and consumed materials.

d. modifies proteins that will be shipped elsewhere in the organism.

e. processes and packages proteins, lipids, and other molecules.

9. In chemistry class we learn the rule "like dissolves like" when studying why polar substances dissolve in each other (like sucrose in water) and why non-polar substances dissolve in each other (like fats in oil). Which of the following statements illustrates this rule?

a. Ribosomes are found inside of prokaryotic cells rather than outside.

b. Prokaryotes lack a nuclear membrane while eukaryotes have one.

c. More prokaryotic cells could fit inside a 1-cm cube than eukaryotic cells could.

d. Transmembrane proteins remain in the plasma membrane even though they are not attached to anything.

e. Chemical messengers or hormones bind tightly to their receptor proteins on the outside of a cell.

10. The "fingerprint" found on the outsides of cells is the BEST underlying explanation for:

a. why you cannot catch HIV by casual contact.

b. why blood can easily be transferred between any two people.

c. why mucus accumulates in the lungs in individuals with cystic fibrosis.

d. why beta blockers reduce anxiety.

e. why a person can successfully donate his heart to another unrelated person.

11. Facilitated diffusion of magnesium ions (Mg++) would occur OUT of a cell if the Mg++ concentration was ________ outside the cell than inside, and ________.

a. higher, Mg++ could move through a transport protein across the membrane

b. higher, Mg++ could move directly through the phospholipid bilayer of the membrane

c. lower, Mg++ could move through a transport protein across the membrane

d. the same, Mg++ could move directly through the phospholipid bilayer of the membrane

e. lower, Mg++ could move directly through the phospholipid bilayer of the membrane

12. Which is NOT true about chloroplasts and mitochondria?

a. Animal cells don't have chloroplasts.

b. Plants have chloroplasts instead of mitochondria.

c. Mitochondria break down food energy to make ATP.

d. Both mitochondria and chloroplasts are involved with energy production.

e. Chloroplasts produce food from sunlight energy.

13. Cellular "fingerprints":

a. are made from cholesterol.

b. are "erased" by the HIV virus.

c. are exposed on the cytoplasmic side of the membrane.

d. can help the immune system distinguish "self" from "non-self."

e. All of the above are correct.

14. The pH of the liquid inside a lysosome is acidic, about 4.5. The molecules normally found inside the lysosome are designed to work best at this pH. Which of the follow statements is the BEST explanation for why the pH of the lysosome interior is so low?

a. Constructive: the acid inside helps lysosomes construct bigger and longer molecules.

b. Protective: if the corrosive broth of a lysosome ever leaked out, the digestive enzymes in it would become non-functional in the higher pH of the cytoplasm.

c. Efficiency: the acid assists the lysosome in performing photosynthesis.

d. Stability: the acidic pH helps keep lysosomes stiff and round.

e. Concentration: acid contains large amounts of H+ ions, necessary for lysosomal ATP production.

15. A scientist tries to build a eukaryotic cell in her laboratory. She remembers to include most of the organelles, but forgets one. Among other abnormalities, her newly created cell cannot synthesize the enzymes needed to detoxify drugs and poisons. Which organelle is missing?

a. the Golgi apparatus

b. the mitochondria

c. the cytoskeleton

d. the smooth endoplasmic reticulum

e. the nucleus

16. What major advantage does the presence of organelles offer eukaryotic cells?

a. They separate chemicals into different compartments, concentrating them for certain reactions.

b. They help to blend together the chemicals throughout the cell.

c. They make eukaryotic cells stronger.

d. They help make eukaryotic cells larger.

e. They greatly simplify eukaryotic cells, making them less complex.

17. Which of the following describes pinocytosis?

a. A cell performs endocytosis, bringing in dissolved particles and liquids.

b. A molecule triggers a receptor on the cell exterior, the cell membrane folds inward.

c. ATP is used to pump sodium ions from outside of the cell inwards through a membrane protein.

d. Vesicles in the cytoplasm dump their "garbage" outside of the cell membrane by fusion with it.

e. An amoeba engulfs a bacterium, bringing it inside of the cell.

18. Which of the following statements is TRUE about a plasma membrane?

a. It is composed of a single layer of phospholipids.

b. It is a rigid structure that protects the cell like a shell.

c. The molecules that make up most of the plasma membrane are polar at their heads and tails.

d. The molecules that make up the membrane are lipids.

e. The molecules that make up the membrane are linked to each other by covalent bonds.

19. In Tay-Sachs disease, a genetic mutation causes a malfunction in a certain organelle that leads to a backup of molecules and proteins, ultimately interfering with the entire functioning of the cell. Which organelle is primarily affected by this disease?

a. the nucleus

b. the Golgi apparatus

c. the endoplasmic reticulum

d. the lysosomes

e. the peroxisomes

20. Which of the following organelles contains a small circular loop of DNA?

a. nucleus

b. Golgi apparatus

c. smooth endoplasmic reticulum

d. lysosomes

e. mitochondria.