Question 1

Which pair of activities are carrier molecules involved in?

Accepted Answer

A)  passive transport and osmosis 
B)  active and passive transport 
C)  active transport and osmosis 
D)  osmosis and diffusion 
A)  passive transport and osmosis 
B)  active and passive transport 
C)  active transport and osmosis 
D)  osmosis and diffusion

Question 2

Patients with cystic fibrosis are very susceptible to bacterial infections. Which of the following best describes why this is the case?

Accepted Answer

A)  Water cannot be pumped into the cells from the mucus lining. 
B)  Water cannot be pumped out of the cells and into the mucus lining. 
C)  Transport protein cannot pump sodium ions out of the lung cells and into the mucus lining; the water then remains in the cells. 
D)  Transport protein cannot pump chloride ions out of the lung cells and into the mucus lining; the water then remains in the cells. 
A)  Water cannot be pumped into the cells from the mucus lining. 
B)  Water cannot be pumped out of the cells and into the mucus lining. 
C)  Transport protein cannot pump sodium ions out of the lung cells and into the mucus lining; the water then remains in the cells. 
D)  Transport protein cannot pump chloride ions out of the lung cells and into the mucus lining; the water then remains in the cells.

Question 3

In the fluid mosaic model of cell membranes, what does the "fluid" part of the model refer to?

Accepted Answer

A)  the constant movement of the hydrophilic tails in the interior of the membrane 
B)  the phospholipid and protein molecules, which move and exchange places within the two layers of phospholipids 
C)  the free movement of cholesterol molecules within the membrane 
D)  a thin layer of water found sandwiched between the two layers of phospholipids 
A)  the constant movement of the hydrophilic tails in the interior of the membrane 
B)  the phospholipid and protein molecules, which move and exchange places within the two layers of phospholipids 
C)  the free movement of cholesterol molecules within the membrane 
D)  a thin layer of water found sandwiched between the two layers of phospholipids

Question 4

Identify the structures indicated in this drawing of a typical plasma membrane.  
-carbohydrate groups

Accepted Answer

The answer of Identify the structures indicated in this drawing...

Question 5

Why do the cells die when the ambient temperature drops to freezing?

Accepted Answer

A)  because of the increased cellular signalling inside the cell 
B)  because of the inhibition of cell division 
C)  because of the inhibition of molecule transport across the cell membrane 
D)  because of the increased metabolic reactions inside the cell 
A)  because of the increased cellular signalling inside the cell 
B)  because of the inhibition of cell division 
C)  because of the inhibition of molecule transport across the cell membrane 
D)  because of the increased metabolic reactions inside the cell

Question 6

Unsaturated fatty acids cause a membrane to be fluid at lower temperatures. What is a reasonable explanation for this?

Accepted Answer

A)  Unsaturated fatty acids permit more water into the interior of the membrane. 
B)  The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be spaced farther apart. 
C)  The double bonds in the unsaturated fatty acids block interaction among the hydrophilic head groups of the lipids. 
D)  Unsaturated fatty acids have a higher cholesterol content. 
A)  Unsaturated fatty acids permit more water into the interior of the membrane. 
B)  The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be spaced farther apart. 
C)  The double bonds in the unsaturated fatty acids block interaction among the hydrophilic head groups of the lipids. 
D)  Unsaturated fatty acids have a higher cholesterol content.

Question 7

When referring to membrane glycolipids and glycoproteins, what does the prefix "glyco-" indicate?

Accepted Answer

A)  polar carbohydrate groups that are attached to the molecules 
B)  nonpolar carbohydrate groups that are attached to the molecules 
C)  the molecules that are attached to the membrane by ionic bonds 
D)  the molecules that are attached to the membrane by covalent bonds 
A)  polar carbohydrate groups that are attached to the molecules 
B)  nonpolar carbohydrate groups that are attached to the molecules 
C)  the molecules that are attached to the membrane by ionic bonds 
D)  the molecules that are attached to the membrane by covalent bonds

Question 8

Which terms refer to the movement of water across a membrane from an area of lower solute concentration to a region of higher solute concentration?

Accepted Answer

A)  both endocytosis and active transport 
B)  both diffusion and endocytosis 
C)  both active transport and osmosis 
D)  both diffusion and osmosis 
A)  both endocytosis and active transport 
B)  both diffusion and endocytosis 
C)  both active transport and osmosis 
D)  both diffusion and osmosis

Question 9

Which statement applies to both simple diffusion and active transport?

Accepted Answer

A)  Transport proteins are not specific for the molecules being transported. 
B)  A concentration gradient is not present. 
C)  A concentration gradient is present. 
D)  Transport proteins are specific for the molecules being transported. 
A)  Transport proteins are not specific for the molecules being transported. 
B)  A concentration gradient is not present. 
C)  A concentration gradient is present. 
D)  Transport proteins are specific for the molecules being transported.

Question 10

What are aquaporins?

Accepted Answer

A)  spaces that transport water molecules 
B)  pores made of water molecules 
C)  protein channels for water transport 
D)  pores found only in bacterial cells 
A)  spaces that transport water molecules 
B)  pores made of water molecules 
C)  protein channels for water transport 
D)  pores found only in bacterial cells

Question 11

Which of the following will diffuse most rapidly across membranes?

Accepted Answer

A)  O2 
B)  glucose 
C)  ions 
D)  macromolecules 
A)  O2 
B)  glucose 
C)  ions 
D)  macromolecules

Question 12

How are exocytosis and endocytosis different?

Accepted Answer

A)  Endocytosis transports small molecules into cells, and exocytosis transports large molecules out of cells. 
B)  Endocytosis transports large molecules into cells, and exocytosis transports large molecules out of cells. 
C)  Endocytosis transports small molecules out of cells, and exocytosis transports small molecules into cells. 
D)  Endocytosis transports large molecules into cells, and exocytosis transports small molecules out of cells. 
A)  Endocytosis transports small molecules into cells, and exocytosis transports large molecules out of cells. 
B)  Endocytosis transports large molecules into cells, and exocytosis transports large molecules out of cells. 
C)  Endocytosis transports small molecules out of cells, and exocytosis transports small molecules into cells. 
D)  Endocytosis transports large molecules into cells, and exocytosis transports small molecules out of cells.

Question 13

How are receptor-mediated endocytosis and pinocytosis similar to each other?

Accepted Answer

A)  They both transport liquids into cells. 
B)  They both transport particles into cells. 
C)  They both transport particles out of cells. 
D)  They both transport liquids out of cells. 
A)  They both transport liquids into cells. 
B)  They both transport particles into cells. 
C)  They both transport particles out of cells. 
D)  They both transport liquids out of cells.

Question 14

How do insects alter membrane fluidity?

Accepted Answer

A)  by adjusting the relative proportions of cholesterol and proteins 
B)  by adjusting the relative proportions of cholesterol and fatty acids 
C)  by adjusting the relative proportions of proteins and fatty acids 
D)  by adjusting the relative proportions of saturated and unsaturated fatty acids 
A)  by adjusting the relative proportions of cholesterol and proteins 
B)  by adjusting the relative proportions of cholesterol and fatty acids 
C)  by adjusting the relative proportions of proteins and fatty acids 
D)  by adjusting the relative proportions of saturated and unsaturated fatty acids

Question 15

Which type of lipid is most important in the structure of biological membranes?

Accepted Answer

A)  wax 
B)  cholesterol 
C)  phospholipid 
D)  fat 
A)  wax 
B)  cholesterol 
C)  phospholipid 
D)  fat

Question 16

Match each mechanism of cellular transport with its correct definition.
-pinocytosis

Accepted Answer

A) movement of a molecule from an area of high concentration to an area of lower concentration 
B) cells internalize molecules into a cell by the inward budding of vesicles possessing receptors specific to the molecule being transported 
C) movement of water from a hypotonic solution into a hypertonic solution across a selectively permeable membrane 
D) large particles are enveloped by the cell membrane and internalized 
E) a process in which liquid droplets are ingested by living cells
F)diffusion of molecules across the plasma membrane with the assistance of transport proteins 
A) movement of a molecule from an area of high concentration to an area of lower concentration 
B) cells internalize molecules into a cell by the inward budding of vesicles possessing receptors specific to the molecule being transported 
C) movement of water from a hypotonic solution into a hypertonic solution across a selectively permeable membrane 
D) large particles are enveloped by the cell membrane and internalized 
E) a process in which liquid droplets are ingested by living cells
F)diffusion of molecules across the plasma membrane with the assistance of transport proteins

Question 17

What does the cell wall do when a plant cell is placed in a hypotonic solution?

Accepted Answer

A)  It prevents diffusion. 
B)  It prevents plasmolysis. 
C)  It prevents the cell from bursting. 
D)  It prevents active transport. 
A)  It prevents diffusion. 
B)  It prevents plasmolysis. 
C)  It prevents the cell from bursting. 
D)  It prevents active transport.

Question 18

Identify the structures indicated in this drawing of a typical plasma membrane.  
-peripheral proteins

Accepted Answer

The answer of Identify the structures indicated in this drawing...

Question 19

Which of the following do carrier proteins often transport?

Accepted Answer

A)  proteins 
B)  steroid hormones 
C)  H2O 
D)  glucose and amino acids 
A)  proteins 
B)  steroid hormones 
C)  H2O 
D)  glucose and amino acids

Question 20

How do the charges inside and outside of the cell compare?

Accepted Answer

A)  There is negative charge inside and positive charge outside of the cell. 
B)  There is positive charge inside and positive charge outside of the cell. 
C)  There is positive charge inside and negative charge outside of the cell. 
D)  There is negative charge inside and negative charge outside of the cell. 
A)  There is negative charge inside and positive charge outside of the cell. 
B)  There is positive charge inside and positive charge outside of the cell. 
C)  There is positive charge inside and negative charge outside of the cell. 
D)  There is negative charge inside and negative charge outside of the cell.

Exam 4: Cell Membranes and Signaling

Which pair of activities are carrier molecules involved in?

Patients with cystic fibrosis are very susceptible to bacterial infections. Which of the following best describes why this is the case?

In the fluid mosaic model of cell membranes, what does the "fluid" part of the model refer to?

Identify the structures indicated in this drawing of a typical plasma membrane. -carbohydrate groups

Why do the cells die when the ambient temperature drops to freezing?

Unsaturated fatty acids cause a membrane to be fluid at lower temperatures. What is a reasonable explanation for this?

When referring to membrane glycolipids and glycoproteins, what does the prefix "glyco-" indicate?

Which terms refer to the movement of water across a membrane from an area of lower solute concentration to a region of higher solute concentration?

Which statement applies to both simple diffusion and active transport?

What are aquaporins?

Which of the following will diffuse most rapidly across membranes?

How are exocytosis and endocytosis different?

How are receptor-mediated endocytosis and pinocytosis similar to each other?

How do insects alter membrane fluidity?

Which type of lipid is most important in the structure of biological membranes?

Match each mechanism of cellular transport with its correct definition. -pinocytosis

What does the cell wall do when a plant cell is placed in a hypotonic solution?

Identify the structures indicated in this drawing of a typical plasma membrane. -peripheral proteins

Which of the following do carrier proteins often transport?

How do the charges inside and outside of the cell compare?

Light and Life

The Cell: an Overview

Energy and Enzymes

Cellular Respiration

Photosynthesis

Cell Cycles

Genetic Recombination

The Chromosomal Basis of Mendelian Inheritance

Genetic Linkage, Sex-Linkage, and Other Non-Mendelian Inheritance Mechanisms

DNA Structure, Replication, and Repair

Gene Structure Expression, and Mutation

Regulation of Gene Expression

Dna Technologies

Genomes

Evolution: the Development of the Theory

Microevolution: Changes Within Populations

Speciation and Macroevolution

Systematics and Phylogenetics: Revealing the Tree of Life

Humans and Evolution

Defining Life and Its Origins

Viruses, Viroids, and Prions: Infectious Biological Particles

Bacteria and Archaea

Protists

Fungi

Plants

Animals

Conservation of Biodiversity

Population Ecology

Species Interactions and Community Ecology

Ecosystems

Animal Behaviour

Organization of the Plant Body

Transport in Plants

Reproduction and Development in Flowering Plants

Plant Nutrition

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Animal Nutrition

Gas Exchange: the Respiratory System

Internal Transport: the Circulatory System

Regulation of the Internal Environment: Water, Solutes, and Temperature

Control of Animal Processes: Endocrine Control

Animal Reproduction

Control of Animal Processes: Neural Control

Muscles, Skeletons, and Body Movements

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