Exam 4: Cell Membranes, Transport, and Communication

Epithelial tissue in animals provides a barrier against the invasion of bacteria into the body.Which of the following is most likely to be responsible for creating a tight enough barrier between cells to prevent the passage of bacteria between them?

In the following flowchart summarizing membrane transport,both active and facilitated transports terminate at separate carrier proteins.Which statement explains why the lines do not converge at the same carrier protein?

You place some Elodea,an aquarium plant,in a hypotonic solution.What happens?

Plants have hormones.

The concentration of solutes is higher within the mitochondria than it is in the cytosol.Therefore,the cytosol is ________ to the inside of the mitochondrion.

A cell that is gaining water from its surroundings is in a(n)________ solution.

Which type of molecule will diffuse through the plasma membrane most quickly?

Several types of lipoproteins exist;the best balance for cardiovascular health is achieved with ________ amount of LDL and ________ amount of HDL.

A positive correlation has been shown between HDL and dementia;unfortunately,lowering HDL without medication is difficult,and serious side effects have been reported.

Cells suspended in a hypertonic solution will lose water.

The various connections between cells,including cell junctions and signaling molecules,allow the cells in a multicellular organism to "talk" to each other,a principle known as cell-to-cell ________.

A red blood cell is placed in a solution and it begins to shrink.Which of the following describes the solution?

Water moves across a membrane from a hypotonic solution to a ________ solution.

Which statement best describes the equilibrium condition shown in the following illustration?

The fragrance of bread baking in a kitchen spreads to other rooms by

You observe a cell in a solution that swells until it bursts.What you have seen is an instance of osmosis in a(n)________ solution.

Active transport

Ingested protein is always degraded to amino acids before absorption in the mature human small intestine,but nursing infants can absorb intact antibodies (large protein molecules)from breast milk.How might this difference in intestinal function be explained?

Animal cells are attached to neighboring cells by all of the following,EXCEPT

Steroids are unable to cross the plasma membrane.