Question 1

Which of the following statements is correct regarding net diffusion?

Accepted Answer

A)   Molecular weight of a substance does not affect the rate.
B)   The lower the temperature, the faster the rate.
C)   The rate is independent of temperature.
D)   The greater the concentration gradient, the faster the rate. D

Question 2

Myocardium (cardiac muscle tissue) must rhythmically contract for a lifetime. This requires a considerable amount of energy production by the cells. You would expect to see a relatively high amount of which organelle in these cells?

Accepted Answer

A)   cytoskeleton
B)   smooth endoplasmic reticulum
C)   mitochondria
D)   lysosomes C

Question 3

Research shows that neurofibrillary tangles associated with the disintegration of microtubules are the primary cause of Alzheimer's disease. If microtubules disintegrate, what then might happen to brain cells?

Accepted Answer

Microtubules determine cell shape and intracellular movement. They are dynamic organelles constantly growing from the centrosome, dissembling, and then reassembling. Without microtubules, the elongated brain cell might either lose shape or lose its ability to move materials from end to end and keep its distant parts well-supplied and alive. Loss of signal followed by cell death result.

Question 4

When tissues are injured or infected, chemical signals can be releases that affect the plasma membrane of cells that line the nearby blood vessels. These blood vessels' cells (endothelial cells) respond to the chemical signals by displaying a type of glycoproteins on their surface. These proteins will attach to circulating white blood cells bringing them to the site of injury or infection. These glycoproteins would best be described as .

Accepted Answer

A)   Cell Adhesion Molecules (CAMs) 
B)   desmosomes
C)   transport proteins
D)   G-proteins

Question 5

Microfilaments are thin strands of the contractile protein composed of myosin.

Accepted Answer

A) True 
 B)False

Question 6

_________is the division of the cytoplasmic mass into two parts.

Accepted Answer

The answer of _________is the division of the cytoplasmic mass...

Question 7

If a cell is selectively reducing the concentration of a particular enzyme in the extracellular fluid it will likely utilize __________ .

Accepted Answer

A)   pinocytosis
B)   phagocytosis
C)   receptor-mediated endocytosis
D)   exocytosis

Question 8

Briefly describe the glycocalyx and its functions.

Accepted Answer

The answer of Briefly describe the glycocalyx and its functions....

Question 9

If a human cell were to increase the amount of cholesterol embedded within its plasma membrane, which of the following would most likely happen?

Accepted Answer

A)   The plasma membrane would become more stable, less fluid, and less permeable.
B)   The cell would form a plaque that could potentially block a blood vessel.
C)   The plasma membrane would become more permeable to ions and less permeable to lipids.
D)   The plasma membrane would become more fluid and the phospholipids less stable.

Question 10

The phase of a cell life cycle in which the DNA is replicated is called _________.

Accepted Answer

The answer of The phase of a cell life cycle...

Question 11

In which stage of mitosis do the identical sets of chromosomes line up along the midline or equator of the cell?

Accepted Answer

A)   prophase
B)   metaphase
C)   telophase
D)   anaphase

Question 12

Osmosis is the passive movement of water, but it follows almost completely opposite laws of physics when compared to the diffusion of ions or other small particles.

Accepted Answer

A) True 
 B)False

Question 13

If cells are placed in a hypotonic solution containing a solute to which the membrane is impermeable, what could happen?

Accepted Answer

A)   The cells will show no change due to diffusion of both solute and solvent.
B)   The cells will lose water and shrink.
C)   The cells will shrink at first, but will later reach equilibrium with the surrounding solution and return to their original condition.
D)   The cells will swell and ultimately burst.

Question 14

The myocardium (cardiac muscle tissue) undergoes a significant amount of physical stress due to its contractions. You would expect to see relatively large numbers of which of the following embedded within their plasma membrane?

Accepted Answer

A)   transport proteins
B)   glycolipids
C)   desmosomes
D)   tight junctions

Question 15

What are lipid rafts? What are their functions?

Accepted Answer

The answer of What are lipid rafts? What are their...

Question 16

Which of the following will NOT speed up the net rate of diffusion for glucose into a cell?

Accepted Answer

A)   Increasing the concentration of glucose outside of the cell.
B)   Decreasing the number of phospholipids in the plasma membrane.
C)   Decreasing the concentration of glucose within the cell.
D)   Increasing the number of glucose transport proteins within the plasma membrane.

Question 17

Aerobic cellular respiration occurs in the_________ .

Accepted Answer

The answer of Aerobic cellular respiration occurs in the_________ ....

Question 18

If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA synthesis is ACGTT, then what would be the sequence of bases in the corresponding mRNA?

Accepted Answer

A)   GUACC
B)   ACGTT
C)   UGCAA
D)   TGCAA

Question 19

At the age of 6 months, Caleb was diagnosed with Tay-Sachs disease. As his primary care physician, what would you tell his parents about this disease?

Accepted Answer

The answer of At the age of 6 months, Caleb...

Question 20

Which of the following is NOT a function of the smooth endoplasmic reticulum?

Accepted Answer

A)   lipid metabolism and cholesterol synthesis
B)   steroid-based hormone synthesis
C)   protein synthesis in conjunction with ribosomes
D)   breakdown of stored glycogen to form free glucose

Exam 3: Cells: the Living Units