Question 1

What is the name of the currently accepted model of membrane structure, and where does it place membrane proteins?

Accepted Answer

A)  fluid- mosaic; on the surfaces of the membrane only 
B)  sandwich; on the outside and inside surfaces of the membrane only 
C)  sandwich; embedded within the membrane and on the surfaces of the membrane 
D)  fluid- mosaic; embedded within the membrane and on the surfaces of the membrane 
A)  fluid- mosaic; on the surfaces of the membrane only 
B)  sandwich; on the outside and inside surfaces of the membrane only 
C)  sandwich; embedded within the membrane and on the surfaces of the membrane 
D)  fluid- mosaic; embedded within the membrane and on the surfaces of the membrane

Question 2

Which of the following crosses lipid bilayers the slowest?

Accepted Answer

A)  a large, polar molecule like glucose 
B)  a sodium ion 
C)  a small, nonpolar molecule like oxygen O2) 
D)  a small, polar molecule like water 
A)  a large, polar molecule like glucose 
B)  a sodium ion 
C)  a small, nonpolar molecule like oxygen O2) 
D)  a small, polar molecule like water

Question 3

Which of the following is not a difference between passive facilitated transport and active transport?

Accepted Answer

A)  Active transport moves substances against their concentration gradient, while facilitated transport moves substances down their concentrations gradient. 
B)  Active transport and facilitated transport both play a role in maintaining proper concentrations of substances in the intra- and extracellular environments. 
C)  Active transport requires a membrane protein to move molecules across the plasma membrane, while facilitated transport does not. 
D)  Active transport requires energy input in the form of ATP, while facilitated transport does not. 
A)  Active transport moves substances against their concentration gradient, while facilitated transport moves substances down their concentrations gradient. 
B)  Active transport and facilitated transport both play a role in maintaining proper concentrations of substances in the intra- and extracellular environments. 
C)  Active transport requires a membrane protein to move molecules across the plasma membrane, while facilitated transport does not. 
D)  Active transport requires energy input in the form of ATP, while facilitated transport does not.

Question 4

Phospholipid bilayer membranes are selectively permeable. What does that mean?

Accepted Answer

A)  They allow everything nonpolar to cross. 
B)  They allow everything but water to cross. 
C)  They allow only water to cross. 
D)  They allow some things to cross while restricting others. 
A)  They allow everything nonpolar to cross. 
B)  They allow everything but water to cross. 
C)  They allow only water to cross. 
D)  They allow some things to cross while restricting others.

Question 5

Which of the following is not true of osmosis?

Accepted Answer

A)  It is a special case of diffusion. 
B)  Water moves from areas of high water concentration to areas of low water concentration. 
C)  It is an energy- demanding or "active" process. 
A)  It is a special case of diffusion. 
B)  Water moves from areas of high water concentration to areas of low water concentration. 
C)  It is an energy- demanding or "active" process.

Question 6

What is the most important factor in explaining why osmosis occurs spontaneously?

Accepted Answer

A)  The process is exothermic. 
B)  It leads to a decrease in entropy. 
C)  It leads to an increase in entropy. 
D)  The process is endothermic. 
A)  The process is exothermic. 
B)  It leads to a decrease in entropy. 
C)  It leads to an increase in entropy. 
D)  The process is endothermic.

Question 7

Which characteristic would be expected in the plasma membranes of a plant that can survive winters in Northern Ontario, compared to a plant growing in a warmer region?

Accepted Answer

A)  higher levels of cholesterol 
B)  a higher percentage of saturated fatty acids 
C)  a higher percentage of unsaturated fatty acids 
D)  additional glycerol molecules packed in between fatty acid tails 
A)  higher levels of cholesterol 
B)  a higher percentage of saturated fatty acids 
C)  a higher percentage of unsaturated fatty acids 
D)  additional glycerol molecules packed in between fatty acid tails

Question 8

What is the most important factor in explaining why diffusion occurs spontaneously?

Accepted Answer

A)  The process is endothermic. 
B)  It leads to a decrease in entropy. 
C)  The process is exothermic. 
D)  It leads to an increase in entropy. 
A)  The process is endothermic. 
B)  It leads to a decrease in entropy. 
C)  The process is exothermic. 
D)  It leads to an increase in entropy.

Question 9

What type of functional group results when the alcohol group on glycerol reacts with the carboxylic acid group on a fatty acid?

Accepted Answer

A)  peptide bond 
B)  ester 
C)  hydrocarbon 
D)  glycosidic bond 
A)  peptide bond 
B)  ester 
C)  hydrocarbon 
D)  glycosidic bond

Question 10

Which of the following observations made with freeze- fracture electron microscopy provides evidence for the fluid- mosaic model of membrane structure?

Accepted Answer

A)  The middle of the membrane viewed under the electron microscope was smooth and regular. 
B)  The exterior surface of the membrane contained pits only. 
C)  The inner surfaces of the membrane contained pits and mounds. 
D)  The exterior surface of the membrane contained pits and mounds. 
A)  The middle of the membrane viewed under the electron microscope was smooth and regular. 
B)  The exterior surface of the membrane contained pits only. 
C)  The inner surfaces of the membrane contained pits and mounds. 
D)  The exterior surface of the membrane contained pits and mounds.

Question 11

Which of the following is the best explanation for why vegetable oil is a liquid at room temperature, while animal fats are solid?

Accepted Answer

A)  Vegetable oil has fewer double bonds than animal fats. 
B)  Vegetable oil has longer fatty- acid tails than animal fats have. 
C)  Vegetable oil has more double bonds than animal fats. 
D)  Animal fats have no amphipathic character. 
A)  Vegetable oil has fewer double bonds than animal fats. 
B)  Vegetable oil has longer fatty- acid tails than animal fats have. 
C)  Vegetable oil has more double bonds than animal fats. 
D)  Animal fats have no amphipathic character.

Question 12

Phospholipids can form all of the following structures in water EXCEPT which one?

Accepted Answer

A)  monolayers 
B)  vesicles 
C)  bilayers 
D)  micelles 
A)  monolayers 
B)  vesicles 
C)  bilayers 
D)  micelles

Question 13

Why do lipid bilayers form spontaneously?

Accepted Answer

A)  The process is exergonic. 
B)  The process is endergonic. 
C)  The process is endothermic. 
D)  The process leads to a huge decrease in entropy and no change in potential energy. 
A)  The process is exergonic. 
B)  The process is endergonic. 
C)  The process is endothermic. 
D)  The process leads to a huge decrease in entropy and no change in potential energy.

Exam 6: Lipids, Membranes, and the First Cells

What is the name of the currently accepted model of membrane structure, and where does it place membrane proteins?

Which of the following crosses lipid bilayers the slowest?

Which of the following is not a difference between passive facilitated transport and active transport?

Phospholipid bilayer membranes are selectively permeable. What does that mean?

Which of the following is not true of osmosis?

What is the most important factor in explaining why osmosis occurs spontaneously?

Which characteristic would be expected in the plasma membranes of a plant that can survive winters in Northern Ontario, compared to a plant growing in a warmer region?

What is the most important factor in explaining why diffusion occurs spontaneously?

What type of functional group results when the alcohol group on glycerol reacts with the carboxylic acid group on a fatty acid?

Which of the following observations made with freeze- fracture electron microscopy provides evidence for the fluid- mosaic model of membrane structure?

Which of the following is the best explanation for why vegetable oil is a liquid at room temperature, while animal fats are solid?

Phospholipids can form all of the following structures in water EXCEPT which one?

Why do lipid bilayers form spontaneously?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Inside the Cell

Energy and Enzymes

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Gene Structure and Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems and Global Ecology

Biodiversity and Conservation Biology

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