Exam 4: Cell Membranes, Transport, and Communication

Tight junctions prevent the movement of the extracellular matrix between cells.

The arrows in the following figure show the movement of water across the cell wall and plasma membrane of a plant cell. For water to move in the direction indicated,the solution surrounding the cell must be

Passive carrier proteins

After a sex hormone enters a target cell,it

You place some Elodea,an aquarium plant,in a hypertonic solution.The cells of the Elodea

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?

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

Muscle cells require high concentrations of calcium to function properly.As a result,these cells use ________ transport to move calcium from areas of low concentration outside the cell into the cytoplasm.

Imagine two solutions separated by a selectively permeable membrane that is impermeable to glucose.On one side of the membrane,solution A contains 10 percent glucose and on the other side,solution B contains 25 percent glucose.Which of the following is true?

Passive carrier molecules often require active carrier proteins to provide amino acids for transport.

You observe a vesicle moving toward the plasma membrane from inside a cell.Once it reaches and fuses with the plasma membrane,you will most likely see an example of

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

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.

Soon after a certain molecule enters a cell,the cell begins producing a new type of protein.The molecule was probably a

Hydrophilic signaling molecules

Cell surface receptors of chemical messages are made of

Hikers can detect a dead skunk along a trail long before they actually see it.What process allows the scent of the skunk to be so widely dispersed?

Imagine a cell needing an essential specific amino acid (one the cell cannot synthesize).What process could acquire the amino acid most quickly?

Active transport requires

Plants have hormones.