Deck 6: Cell Membranes, Transport, and Communication

Question 1

Multicellular organisms have various specialized cells because

A) any one cell can contain only one kind of organelle.
B) each kind of cell is able to function in isolation.
C) specialized cells ensure that processes necessary for life occur efficiently.
D) the DNA of cells is not accurately copied.

Answer 1

C

Question 2

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

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

Answer 2

D

Question 3

The figure below illustrates a plasma membrane.
Which molecule in the figure above is undergoing active transport?

A) ATP
B) Na+
C) K+
D) both Na+ and K+

Answer 3

D

Question 4

Passive carrier proteins

A) bind to phospholipids in the plasma membrane and move them into the cell.
B) bind to specific external molecules and aid in the formation of vesicles entering the cell.
C) create tunnels in the plasma membrane for specific solutes to diffuse through.
D) change shape upon binding to specific external molecules and then release the molecule on the other side of the membrane.

Question 5

The figure below shows the movement of solutes across a plasma membrane in the direction indicated by the arrows.
This movement across the membrane

A) requires energy.
B) utilizes carrier proteins.
C) occurs through diffusion.
D) is an example of osmosis.

Question 6

Active transport requires

A) energy.
B) diffusion.
C) hormones.
D) osmosis.

Question 7

Which of the following would supply energy directly to an active carrier protein?

A) starch
B) sugars
C) ATP
D) fatty acids

Question 8

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

A) active transport.
B) diffusion.
C) osmosis.
D) selective permeation.

Question 9

The arrows in the figure below show the movement of water in relation to a plant cell.
For water to move in the direction indicated, _________ solution must surround the cell.

A) hypertonic
B) hypotonic
C) isotonic
D) selectively permeable

Question 10

Active transport

A) moves substances out of but not into cells.
B) occurs in dense patches far removed from passive carrier proteins.
C) moves substances from areas of high concentration to areas of low concentration.
D) involves a carrier protein.

Question 11

You observe a cell in a solution swelling until it bursts. You have seen an instance of osmosis in

A) a hypertonic solution.
B) an isotonic solution.
C) a hypotonic solution.
D) an exotonic solution.

Question 12

Two solutions are separated by a selectively permeable membrane that is not permeable 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?

A) Solution A is hypertonic.
B) The solutions are isotonic.
C) Water would move from solution A to solution B.
D) Glucose would move from solution B to solution A.

Question 13

Substances move into a cell by

A) pinocytosis.
B) endocytosis.
C) phagocytosis.
D) all of the above

Question 14

A cell that is gaining water from its surroundings is in

A) hypertonic solution.
B) hypotonic solution.
C) isotonic solution.
D) endotonic solution.

Question 15

A white blood cell at the site of a puncture wound engulfs a large cluster of bacteria forming a large internal vesicle. This is an example of

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

Question 16

Which of the following could not easily diffuse across a plasma membrane?

A) sugar molecules
B) water molecules
C) oxygen molecules
D) carbon dioxide molecules

Question 17

Osmosis

A) requires energy.
B) moves substances from areas of high concentration to areas of low concentration.
C) is a form of passive transport.
D) involves exocytosis.

Question 18

The concentration of glucose inside of a cell is higher than the concentration outside of that cell, yet glucose continues to enter the cell. This is an example of

A) passive transport.
B) diffusion.
C) active transport.
D) osmotic transport.

Question 19

To coordinate the functions of specialized cells, those cells must be able to

A) communicate.
B) replicate.
C) move from place to place.
D) cut up certain proteins.

Question 20

One of the major functions of the plasma membrane is to

A) prevent the loss of proteins from mitochondria.
B) contract and give animals their ability to move.
C) control what enters and leaves a cell.
D) provide physical support to the nucleus.

Question 21

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

A) anchoring junctions
B) gap junctions
C) tight junctions
D) plasmodesmata

Question 22

Which of the following are found in plants?

A) plasmodesmata
B) tight junctions
C) gap junctions
D) anchoring junctions

Question 23

What is the effect of the signaling molecule nitric oxide?

A) It causes the diameter of blood vessels to expand.
B) It decreases blood flow to the heart.
C) It allows an organism to respond rapidly to dangerous situations.
D) It causes an increase in blood pressure.

Question 24

Animal cells are attached to neighboring cells by

A) their extracellular matrix.
B) gap junctions.
C) tight junctions.
D) all of the above

Question 25

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

A) receptor molecule.
B) hydrophilic molecule.
C) carrier protein.
D) hydrophobic hormone.

Question 26

Signaling molecules can affect a cell from the outside by interacting with specific receptors that are located

A) in the plasma membrane.
B) within the cell's organelles.
C) within chloroplasts.
D) on the cell wall.

Question 27

Which of the following statements about hormones is false?

A) They are not used in the part of the body where they are produced.
B) They are long-range signaling molecules.
C) They are not used by multicellular organisms.
D) They are transported in an organism by fluids.

Question 28

Hydrophilic signaling molecules

A) move into cells by active transport through carrier protein channels.
B) bind to cell surface receptors and do not enter cells.
C) can passively cross the plasma membrane and bind to intracellular receptor proteins.
D) move directly into the nucleus through carrier proteins that span the distance from the plasma membrane to the nuclear envelope.

Question 29

Signaling molecules can be "tagged" by attaching glow-in-the-dark molecules to them. After adding tagged signaling molecules to the fluid around several cells, you observe the cells with a microscope designed to see glow-in-the-dark molecules. After a few minutes, you notice that the plasma membranes of some of the cells begins to glow. This observation indicates that some cells

A) have more dense plasma membranes than others.
B) have receptors for the signaling molecule.
C) have no active carrier proteins for the signaling molecules.
D) block the signaling molecules by repelling them.

Question 30

After a steroid hormone enters a target cell it

A) binds to the nucleus.
B) becomes a signaling protein.
C) binds to an internal receptor protein.
D) becomes a gene.

Question 31

Cell surface receptors of chemical messages are made of

A) protein.
B) DNA.
C) lipids.
D) sugars.

Question 32

The human hormone insulin is produced only by a single organ, the pancreas, yet insulin is used to move glucose from the bloodstream into cells all over the body. What aspect of hormones makes it possible for insulin to work throughout the body?

A) Hormones are able to stop cell-to-cell communication.
B) Hormones all cross cell membranes, and thus can move freely throughout the body.
C) Hormones cause rapid cell-to-cell signaling.
D) Hormones are long-range signaling molecules.

Question 33

All steroid hormones are derived from

A) cholesterol.
B) progesterone.
C) testosterone.
D) adrenaline.

Question 34

People are often warned to watch their blood cholesterol level to be sure it does not become too high. In fact, some people do not eat any cholesterol-containing foods at all. Even though we associate elevated cholesterol levels with a risk of heart attack and stroke, why does the body make some cholesterol even if none is eaten?

A) Cholesterol is the basis of all steroid hormones in the body.
B) Cholesterol is used by the mitochondria for cellular respiration.
C) Cholesterol is a short-range signaling molecule that does not last long in the body.
D) Cholesterol is a key component of DNA.

Question 35

To coordinate the contraction of the numerous muscle cells that form the heart, signals must travel rapidly between muscle cells. In order to allow this rapid communication, muscle cells in the heart must be connected by

A) tight junctions.
B) gap junctions.
C) anchoring junctions.
D) carrier proteins.

Question 36

All steroid hormones are hydrophobic. Where would you expect the receptor proteins for hormones to be located?

A) In the hydrophobic portion of the cell membrane.
B) In the hydrophilic portion of the cell membrane.
C) In the cytoplasm of a cell.
D) In the extracellular matrix.

Question 37

Short-lived signaling molecules are most effective for

A) long-distance cell-to-cell communication.
B) local cell-to-cell communication.
C) activating genes in the nucleus.
D) breaking down receptor proteins.

Question 38

The proposed role of capsaicin in anesthesia during surgery is to

A) bind to internal receptors, preventing the transmission of electrical signals from pain receptors to the brain.
B) open channel proteins found only on pain-sensing neurons, allowing an anesthetic to enter those cells alone.
C) increase the rate at which calcium ions enter a nerve cell.
D) block the transmission of electrical signals between nerve cells and muscle cells.

Question 39

Cell signaling

A) is always a rapid process.
B) can be fast or slow.
C) is always a slow process.
D) does not occur in plants.

Question 40

Which of the following signaling molecules would not be found in animals?

A) auxin
B) insulin
C) adrenalin
D) acetylcholine

Question 41

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.

Question 42

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

Question 43

Channel proteins provide a means for large _____________ [hydrophobic or hydrophilic] molecules to move across the plasma membrane.

Question 44

When the solute concentration outside of a cell is equal to the solute concentration inside of the cell, the cell is in a(n) ____________ solution.

Question 45

_____________ junctions act as protein "hooks" between cells in heart muscle.

Question 46

When you eat a meal, cells in your pancreas deliver insulin by the process of _________.

Question 47

Even though the amount of water in a cell remains constant in an isotonic solution, water is constantly moving both ways across the plasma membrane by the process of ___________.

Question 48

The passive movement of water across a selectively permeable membrane is called ________.

Question 49

The viscous coating found around most animal cells is called the extracellular _________.

Question 50

The principle of cell _______ is that different cells in the same organism may have different functions.

Question 51

Cells in our liver take up cholesterol by receptor-mediated _____________.

Question 52

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

Question 53

A concentration ______ is said to exist when a molecule is more abundant in one area than it is in another.

Question 54

Active carrier proteins use energy to carry passive carrier proteins into cells.

Question 55

Receptors in target cells can be located in the plasma membrane, the cytosol, or the __________.

Question 56

The concentration of solutes is higher within the mitochondria than it is in the cytosol. The cytosol is ______ [hypertonic, hypotonic, or isotonic] to the inside of the mitochondrion.

Question 57

Channel proteins require energy for transporting molecules across the plasma membrane

Question 58

After entering its target cell, a hormone binds to its receptor and interacts with the cell's DNA, resulting in the production of a specific _______.

Question 59

Hydrophilic signaling molecules interact with cells by interacting with cell surface _____.

Question 60

During ___________ endocytosis, specific substances interact with proteins located on the plasma membrane of the cell.

Question 61

Plants have hormones.

Question 62

The hormone insulin initiates a signal transduction pathway that results in the uptake of glucose by cells. In the early stages of many cases of type II diabetes, people produce insulin but their cells are unable to allow the glucose to enter. Provide a hypothesis as to why this might be the case.

Question 63

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

Question 64

A given signaling molecule can bind to several different kinds of cell surface receptors.

Question 65

Active carrier proteins can transfer molecules into areas of higher concentration.

Question 66

Gap junctions allow large molecules to move from cell to cell.

Question 67

Cell-to-cell communication in humans involves the brain.

Question 68

Steroids are unable to cross the plasma membrane.

Question 69

Osmoregulation refers to balancing water concentrations in organisms and cells.

Question 70

Plasmodesmata are not found in animal cells.

Question 71

Cells surrounded by a hypertonic solution would lose water.

Question 72

Active carrier proteins are not found in the same cells as passive carrier proteins.

Question 73

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