Question 1

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

Accepted Answer

The answer of The passive movement of water across a...

Question 2

If a red blood cell is placed in a hypertonic solution,what happens to it?

Accepted Answer

A)  It will burst. 
B)  It will shrink. 
C)  There will be no change in the red blood cell. 
D)  Water will move into the red blood cell faster than it will move out. 
A)  It will burst. 
B)  It will shrink. 
C)  There will be no change in the red blood cell. 
D)  Water will move into the red blood cell faster than it will move out.

Question 3

Passive carrier proteins

Accepted Answer

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 through which specific solutes can diffuse. 
D)  change shape upon binding to specific external molecules and then release the molecule on the other side of the membrane. 
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 through which specific solutes can diffuse. 
D)  change shape upon binding to specific external molecules and then release the molecule on the other side of the membrane.

Question 4

Sex hormones are able to interact with their receptors in the cytoplasm or in a membrane-bound organelle like the nucleus because they are

Accepted Answer

A)  isotonic. 
B)  hydrophobic. 
C)  hydrophilic. 
D)  very large. 
A)  isotonic. 
B)  hydrophobic. 
C)  hydrophilic. 
D)  very large.

Question 5

Elevated HDL (high-density lipoprotein)levels seem to provide positive cardiovascular health effects,even for individuals with abnormally high blood cholesterol.What best describes the beneficial action of HDL?

Accepted Answer

A)  HDL lines the blood vessel walls,preventing the attachment of cholesterol and the consequential inflammation that follows. 
B)  HDL is an anti-inflammatory agent;it suppresses the inflammatory response in blood vessel walls following the entry of cholesterol. 
C)  HDL has cardiostimulatory effects;it elevates heart rate and blood pressure in a fashion similar to exercise. 
D)  HDL collects surplus cholesterol from peripheral tissues and transports it to the liver,reproductive,and adrenal glands where it is converted to bile or hormones. 
A)  HDL lines the blood vessel walls,preventing the attachment of cholesterol and the consequential inflammation that follows. 
B)  HDL is an anti-inflammatory agent;it suppresses the inflammatory response in blood vessel walls following the entry of cholesterol. 
C)  HDL has cardiostimulatory effects;it elevates heart rate and blood pressure in a fashion similar to exercise. 
D)  HDL collects surplus cholesterol from peripheral tissues and transports it to the liver,reproductive,and adrenal glands where it is converted to bile or hormones.

Question 6

Short-lived signaling molecules are most effective for

Accepted Answer

A)  long-distance cell-to-cell communication. 
B)  local cell-to-cell communication. 
C)  activating genes in the nucleus. 
D)  breaking down receptor proteins. 
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 7

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

Accepted Answer

A) True 
 B)False

Question 8

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

Accepted Answer

A)  begin to hemolyze. 
B)  start to burst. 
C)  shrink. 
D)  undergo plasmolysis. 
A)  begin to hemolyze. 
B)  start to burst. 
C)  shrink. 
D)  undergo plasmolysis.

Question 9

Multicellular organisms have various specialized cells because

Accepted Answer

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. 
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.

Question 10

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

Accepted Answer

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

Question 11

One of the major functions of the plasma membrane is to

Accepted Answer

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. 
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 12

Some hormones,like thyroxine,affect most or all body cells,while others only affect a single organ or type of cell.This is because of variations in

Accepted Answer

A)  hormone concentration-when present in high concentration,a hormone can stimulate a greater number of body locations. 
B)  receptor distribution-all cells or organs with receptors for the hormone will be affected. 
C)  membrane permeability-hydrophobic hormones enter and affect all cells,whereas hydrophilic hormones have more limited affects. 
D)  signal transduction-only cells with the appropriate enzymes needed to activate the hormone will respond to its signal. 
A)  hormone concentration-when present in high concentration,a hormone can stimulate a greater number of body locations. 
B)  receptor distribution-all cells or organs with receptors for the hormone will be affected. 
C)  membrane permeability-hydrophobic hormones enter and affect all cells,whereas hydrophilic hormones have more limited affects. 
D)  signal transduction-only cells with the appropriate enzymes needed to activate the hormone will respond to its signal.

Question 13

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

Accepted Answer

The answer of Receptors in target cells can be located...

Question 14

Which of the following is found in plants?

Accepted Answer

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

Question 15

Lipids often move within the body in complexes known as lipoproteins;what advantage does this strategy provide?

Accepted Answer

A)  Lipids alone have high solubility in body fluids and would be difficult to transport. 
B)  With a protein component as an identifier,cells needing lipids can use membrane receptors and acquire only as much lipid as they need at any given moment. 
C)  Rather than simply diffusing into adjacent cell membranes as free lipids would do,surplus lipoproteins can be routed to the kidneys for disposal or modification. 
D)  Lipids associated with lipoproteins are more likely to be able to pass freely through the cell membrane. 
A)  Lipids alone have high solubility in body fluids and would be difficult to transport. 
B)  With a protein component as an identifier,cells needing lipids can use membrane receptors and acquire only as much lipid as they need at any given moment. 
C)  Rather than simply diffusing into adjacent cell membranes as free lipids would do,surplus lipoproteins can be routed to the kidneys for disposal or modification. 
D)  Lipids associated with lipoproteins are more likely to be able to pass freely through the cell membrane.

Question 16

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

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

A)  requires a direct input of cellular energy. 
B)  occurs independently of carrier proteins. 
C)  occurs by diffusion. 
D)  is an example of osmosis. 
A)  requires a direct input of cellular energy. 
B)  occurs independently of carrier proteins. 
C)  occurs by diffusion. 
D)  is an example of osmosis.

Question 18

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?

Accepted Answer

A)  osmosis 
B)  active transport 
C)  diffusion 
D)  transduction 
A)  osmosis 
B)  active transport 
C)  diffusion 
D)  transduction

Question 19

The following figure illustrates a plasma membrane.
 
Which substance in the figure is crossing the membrane using simple diffusion?

Accepted Answer

A)  Ca2+ 
B)  Na+ 
C)  K+ 
D)  H2O 
A)  Ca2+ 
B)  Na+ 
C)  K+ 
D)  H2O

Question 20

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

Accepted Answer

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

Exam 4: Cell Membranes, Transport, and Communication

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

If a red blood cell is placed in a hypertonic solution,what happens to it?

Passive carrier proteins

Sex hormones are able to interact with their receptors in the cytoplasm or in a membrane-bound organelle like the nucleus because they are

Elevated HDL (high-density lipoprotein)levels seem to provide positive cardiovascular health effects,even for individuals with abnormally high blood cholesterol.What best describes the beneficial action of HDL?

Short-lived signaling molecules are most effective for

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

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

Multicellular organisms have various specialized cells because

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

One of the major functions of the plasma membrane is to

Some hormones,like thyroxine,affect most or all body cells,while others only affect a single organ or type of cell.This is because of variations in

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

Which of the following is found in plants?

Lipids often move within the body in complexes known as lipoproteins;what advantage does this strategy provide?

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

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

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?

The following figure illustrates a plasma membrane. Which substance in the figure is crossing the membrane using simple diffusion?

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

The Nature of Science and the Characteristics of Life

The Chemistry of Life

Cell Structure and Internal Compartments

Energy, Metabolism, and Enzymes

Photosynthesis and Cellular Respiration

Cell Division

Cancer and Human Health

Patterns of Inheritance

Chromosomes and Human Genetics

DNA and Genes

From Gene to Protein

DNA Technology

How Evolution Works

The Origin of Species

The Evolution of Biodiversity

Biological Diversity, Bacteria, and Archaea

Protista, Plantae, and Fungi

Animalia

The Biosphere

Growth of Populations

Animal Behavior

Ecological Communities

Ecosystems

Global Change

Internal Organization and Homeostasis

Nutrition and Digestion

Circulation and Gas Exchange

Animal Hormones

Nervous and Sensory Systems

Skeletons,Muscles,and Movement

The Immune System

Reproduction and Development

Plant Structure, Nutrition, and Transport

Plant Growth and Reproduction

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