In the plasma membrane, _____________ form(s) the lipid bilayer, _____________ determine(s) the fluid nature of the membrane, and _____________ mainly determine(s) the function of the membrane.
|A)||phospholipids, cholesterol, proteins|
|B)||phospholipids, proteins, cholesterol|
|C)||proteins, cholesterol, phospholipids|
|D)||cholesterol, phospholipids, proteins|
|E)||cholesterol, proteins, phospholipids|
Which of the following are functions of the proteins found in the plasma membrane?
|E)||all of the above|
Integrins in the plasma membrane function as
In general, lipid-soluble molecules diffuse through the _____________; small, water-soluble molecules diffuse through the _____________.
|A)||membrane channels, membrane channels|
|B)||membrane channels, lipid bilayer|
|C)||lipid bilayer, carrier molecules|
|D)||lipid bilayer, membrane channels|
|E)||carrier proteins, membrane channels|
Small pieces of matter, and even whole cells, can be transported across the plasma membrane in
The rate of diffusion increases if the
|A)||concentration gradient decreases.|
|B)||temperature of a solution decreases.|
|C)||viscosity of a solution decreases.|
|D)||all of the above.|
Concerning the process of diffusion, at equilibrium
|A)||the net movement of solutes stops.|
|B)||random molecular motion continues.|
|C)||there is an equal movement of solute in opposite directions.|
|D)||concentration of solute is equal throughout the solution.|
|E)||all of the above.|
Which of these statements about osmosis is true?
|A)||Osmosis always involves a membrane that allows water and all solutes to diffuse through it.|
|B)||The greater the solute concentration, the smaller the osmotic pressure of a solution.|
|C)||Osmosis moves water from a greater solute concentration to a lesser solute concentration.|
|D)||The greater the osmotic pressure of a solution, the greater the tendency for water to move into the solution.|
|E)||Osmosis occurs because of hydrostatic pressure outside the cell.|
If a cell is placed in a _____________ solution, lysis of the cell may occur.
Container A contains a 10% salt solution, and container B contains a 20% salt solution. If the two solutions are connected, the net movement of water by diffusion is from _____________ to _____________, and the net movement of salt by diffusion is from _____________ to _____________.
Suppose that a woman ran a long-distance race in the summer. During the race she lost a large amount of hyposmotic sweat. You would expect her cells to
|C)||stay the same.|
Suppose that a man is doing heavy exercise in the hot summer sun. He sweats profusely. He then drinks a large amount of distilled water. After he drank the water, you would expect his tissue cells to
|C)||remain the same.|
Unlike diffusion and osmosis, filtration depends on a _____________ on the two sides of the partition.
|C)||difference in electric charge|
|D)||difference in osmotic pressure|
Which of these statements about facilitated diffusion is true?
|A)||In facilitated diffusion, net movement is down the concentration gradient.|
|B)||Facilitated diffusion requires the expenditure of energy.|
|C)||Facilitated diffusion does not require a carrier protein.|
|D)||Facilitated diffusion moves materials through membrane channels.|
|E)||Facilitated diffusion moves materials in vesicles.|
Which of these statements concerning cotransport of glucose into cells is true?
|A)||The sodium-potassium exchange pump moves Na+ into cells.|
|B)||The concentration of Na+ outside cells is less than inside cells.|
|C)||A carrier protein moves Na+ into cells and glucose out of cells.|
|D)||The concentration of glucose can be greater inside cells than outside cells.|
|E)||As Na+ is actively transported into the cell, glucose is carried along.|
A white blood cell ingests solid particles by forming vesicles. This describes the process of
|C)||secondary active transport.|
Given these characteristics:
1. requires energy
2. requires carrier proteins
3. requires membrane channels
4. requires vesicles
Choose the characteristics that apply to exocytosis.
|C)||1, 3, 4|
|D)||1, 2, 3|
|E)||1, 2, 3, 4|
Cytoplasm is found
|A)||in the nucleus.|
|B)||outside the nucleus and inside the plasma membrane.|
|C)||outside the plasma membrane.|
|E)||everywhere in the cell.|
Which of these elements of the cytoskeleton is composed of tubulin and forms essential components of centrioles, spindle fibers, cilia, and flagella?
Cylindrically shaped extensions of the plasma membrane that do not move, and are supported with actin filaments; they may function in absorption or as sensory receptors. This describes
A large structure, normally visible in the nucleus of a cell, where ribosomal subunits are produced
A cell that synthesizes large amounts of protein for use outside the cell has a large
|A)||number of cytoplasmic inclusions.|
|B)||number of mitochondria.|
|C)||amount of rough endoplasmic reticulum.|
|D)||amount of smooth endoplasmic reticulum.|
|E)||number of lysosomes.|
Which of these organelles produces large amounts of ATP?
Mature red blood cells cannot
|C)||synthesize new protein.|
|D)||use glucose as a nutrient.|
For each glucose molecule, aerobic respiration may produce up to _____________ ATP and 6 CO2 molecules, whereas anaerobic respiration produces _____________ ATP and 2 lactic acid molecules.
A portion of an mRNA molecule that determines one amino acid in a polypeptide chain is called a
In which of these organelles is mRNA synthesized?
During the cell life cycle, DNA replication occurs during the
Given the following activities:
3. gamete production
Which of the activities are the result of mitosis?
|E)||1, 2, 4|