Question 1

Why is the smooth endoplasmic reticulum unable to synthesize proteins?

Accepted Answer

A) because it has no ribosomes 
B) because there is no supply of free amino acids that it can easily access 
C) because it stores calcium which is a known inhibitor of protein synthesis 
D) because it has no DNA to direct synthesis of proteins 
A) because it has no ribosomes 
B) because there is no supply of free amino acids that it can easily access 
C) because it stores calcium which is a known inhibitor of protein synthesis 
D) because it has no DNA to direct synthesis of proteins A

Question 2

Actin filaments have polarity.This means that the two ends can be identified due to structural differences.The plus end is the end to which subunits are added more rapidly,or the end of polymerization.Which of the following would enable you to identify the plus end of actin filaments?

Accepted Answer

A) Add radiolabeled actin subunits to a mixture of actin filaments in which conditions are favorable for polymerization. 
B) Add radiolabeled actin subunits to a mixture of actin filaments in which conditions favor depolymerization. 
C) Determine the ionic charge of the ends of the actin filaments. 
A) Add radiolabeled actin subunits to a mixture of actin filaments in which conditions are favorable for polymerization. 
B) Add radiolabeled actin subunits to a mixture of actin filaments in which conditions favor depolymerization. 
C) Determine the ionic charge of the ends of the actin filaments. A

Question 3

Which of the following statements represents a major difference between prokaryotic cells and eukaryotic cells?

Accepted Answer

A) Prokaryotes have cells while eukaryotes do not. 
B) Eukaryotic cells tend to have much more extensive inner membrane systems and larger numbers of intracellular organelles than do prokaryotes. 
C) Prokaryotes are not able to carry out aerobic respiration,a process that requires a complex inner-membrane system. 
D) Prokaryotes are generally larger in size than eukaryotes. 
A) Prokaryotes have cells while eukaryotes do not. 
B) Eukaryotic cells tend to have much more extensive inner membrane systems and larger numbers of intracellular organelles than do prokaryotes. 
C) Prokaryotes are not able to carry out aerobic respiration,a process that requires a complex inner-membrane system. 
D) Prokaryotes are generally larger in size than eukaryotes. B

Question 4

Where are the proteins that will be exported (excreted)from the cell made?

Accepted Answer

A) in free ribosomes 
B) in ribosomes that attach to the endoplasmic reticulum 
C) in ribosomes that attach to the Golgi complex 
D) in ribosomes that attach to the outer mitochondrial membrane 
A) in free ribosomes 
B) in ribosomes that attach to the endoplasmic reticulum 
C) in ribosomes that attach to the Golgi complex 
D) in ribosomes that attach to the outer mitochondrial membrane

Question 5

Which of the following statements would best describe a cell that has an extensive area of smooth endoplasmic reticulum?

Accepted Answer

A) It plays a role in storage. 
B) It synthesizes large quantities of lipids. 
C) It actively exports protein molecules. 
D) It is able to both import and export protein molecules. 
A) It plays a role in storage. 
B) It synthesizes large quantities of lipids. 
C) It actively exports protein molecules. 
D) It is able to both import and export protein molecules.

Question 6

Which one of the following would you fail to find in a prokaryote?

Accepted Answer

A) DNA 
B) a cell wall 
C) a mitochondrion 
D) a plasma membrane 
A) DNA 
B) a cell wall 
C) a mitochondrion 
D) a plasma membrane

Question 7

Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein in the red blood cells (RBCs).What do you suspect is the consequence of such a defect?

Accepted Answer

A) abnormally shaped RBCs 
B) an insufficient energy supply in the RBCs 
C) an insufficient supply of oxygen-transporting proteins in the RBCs 
D) adherence of RBCs to blood vessel walls causing plaque formation 
A) abnormally shaped RBCs 
B) an insufficient energy supply in the RBCs 
C) an insufficient supply of oxygen-transporting proteins in the RBCs 
D) adherence of RBCs to blood vessel walls causing plaque formation

Question 8

The small intestine is the site of digestion and absorption of nutrients.A single layer of epithelial cells lines the small intestine.In the duodenum (the first section of the small intestine),these epithelial cells secrete large quantities of digestive enzymes.Which of the following features would you expect to find in these epithelial cells?

Accepted Answer

A) They would contain large numbers of lysosomes. 
B) They would have more smooth endoplasmic reticulum than rough endoplasmic reticulum. 
C) They would contain large quantities of rough endoplasmic reticulum. 
D) They would have larger nuclei than cells that secrete large quantities of lipids. 
A) They would contain large numbers of lysosomes. 
B) They would have more smooth endoplasmic reticulum than rough endoplasmic reticulum. 
C) They would contain large quantities of rough endoplasmic reticulum. 
D) They would have larger nuclei than cells that secrete large quantities of lipids.

Question 9

Why are lysosomes considered part of the endomembrane system?

Accepted Answer

A) because they deposit end products of digestion in the endoplasmic reticulum 
B) because they facilitate movement between stacks of the Golgi 
C) because they are formed from products synthesized by the endoplasmic reticulum and processed by the Golgi 
D) because they are composed largely of phospholipids 
A) because they deposit end products of digestion in the endoplasmic reticulum 
B) because they facilitate movement between stacks of the Golgi 
C) because they are formed from products synthesized by the endoplasmic reticulum and processed by the Golgi 
D) because they are composed largely of phospholipids

Question 10

How is the structure of kinesin related to its function?

Accepted Answer

A) Kinesin has two intertwined polypeptides that make up the stalk and enable it to contract and shorten. 
B) Kinesin has a tail region that binds to vesicles and two heads that can attach to microtubules. 
C) The kinesin tail has an ATP binding site to fuel its activities. 
D) Kinesin has two heads to attach to the vesicle being moved,and a tail region that attaches to microtubules. 
A) Kinesin has two intertwined polypeptides that make up the stalk and enable it to contract and shorten. 
B) Kinesin has a tail region that binds to vesicles and two heads that can attach to microtubules. 
C) The kinesin tail has an ATP binding site to fuel its activities. 
D) Kinesin has two heads to attach to the vesicle being moved,and a tail region that attaches to microtubules.

Question 11

What is the function of the nuclear pore complex that is found in all eukaryotes?

Accepted Answer

A) It regulates the movement of all molecules into and out of the nucleus. 
B) It synthesizes the proteins required to copy DNA and make mRNA. 
C) It selectively transports molecules out of the nucleus,but prevents all inbound molecules from entering the nucleus. 
D) It assembles ribosomes from raw materials that are synthesized in the nucleus. 
A) It regulates the movement of all molecules into and out of the nucleus. 
B) It synthesizes the proteins required to copy DNA and make mRNA. 
C) It selectively transports molecules out of the nucleus,but prevents all inbound molecules from entering the nucleus. 
D) It assembles ribosomes from raw materials that are synthesized in the nucleus.

Question 12

Eukaryotic cells manufacture cytoskeletal proteins that help to maintain the cells' shapes and functions.What would you predict about these proteins?

Accepted Answer

A) They would initially contain signal sequences that would allow their entrance into the endoplasmic reticulum. 
B) They would be manufactured on free ribosomes in the cytoplasm. 
C) They would be glycosylated in the Golgi apparatus. 
D) They might travel to the nucleus in a transport vesicle with a specific zip code. 
A) They would initially contain signal sequences that would allow their entrance into the endoplasmic reticulum. 
B) They would be manufactured on free ribosomes in the cytoplasm. 
C) They would be glycosylated in the Golgi apparatus. 
D) They might travel to the nucleus in a transport vesicle with a specific zip code.

Question 13

Flagella and cilia bend or move,imparting mobility to cells.How do these structures move?

Accepted Answer

A) The basal body at the base of the structure hydrolyzes ATP,causing a conformational change that results in movement of the cilium or flagellum. 
B) Two microtubules at the core of the structure serve as motor proteins. 
C) Axonemes are structured such that movement is constant. 
D) Dynein is a motor protein that hydrolyzes ATP and is responsible for movement of the cilium or flagellum. 
A) The basal body at the base of the structure hydrolyzes ATP,causing a conformational change that results in movement of the cilium or flagellum. 
B) Two microtubules at the core of the structure serve as motor proteins. 
C) Axonemes are structured such that movement is constant. 
D) Dynein is a motor protein that hydrolyzes ATP and is responsible for movement of the cilium or flagellum.

Question 14

Amoebae move by crawling over a surface (cell crawling).Which one of the following processes is part of this type of movement?

Accepted Answer

A) growth of actin filaments to form bulges in the plasma membrane 
B) setting up microtubule extensions that vesicles can follow in the movement of cytoplasm 
C) reinforcing the pseudopod with intermediate filaments 
D) cytoplasmic streaming 
A) growth of actin filaments to form bulges in the plasma membrane 
B) setting up microtubule extensions that vesicles can follow in the movement of cytoplasm 
C) reinforcing the pseudopod with intermediate filaments 
D) cytoplasmic streaming

Question 15

You have a distant cousin,age 4,who is always tired and fatigued and is not able to play games and sports like other healthy children.He most likely has an enzyme deficiency or defect associated with which intracellular organelle?

Accepted Answer

A) lysosomes 
B) Golgi apparatus 
C) ribosomes 
D) mitochondria 
A) lysosomes 
B) Golgi apparatus 
C) ribosomes 
D) mitochondria

Question 16

Which of the following statements would be true about lysosomes that lack mannose-6-phosphate receptors?

Accepted Answer

A) They receive "modified" enzymes,so are unable to break down carbohydrates. 
B) They do not receive enzyme shipments from the Golgi apparatus. 
C) They have unstable membranes. 
D) They stick to transport vesicles and impede the transfer of enzymes. 
A) They receive "modified" enzymes,so are unable to break down carbohydrates. 
B) They do not receive enzyme shipments from the Golgi apparatus. 
C) They have unstable membranes. 
D) They stick to transport vesicles and impede the transfer of enzymes.

Question 17

Flagella are found in both eukaryotic cells and prokaryotic cells.Despite the functional similarities of all flagella,scientists suspect that eukaryotic and prokaryotic flagella have evolved independently.Why don't they think there is a common evolutionary origin for prokaryotic and eukaryotic flagella?

Accepted Answer

A) Eukaryotic flagella undergo an undulating motion and are covered by a plasma membrane;prokaryotic flagella move by rotating and lack a plasma membrane. 
B) Prokaryotic flagella do not protrude outside the cell wall,whereas eukaryotic flagella are membrane-bound extensions of cytoplasm. 
C) Prokaryotic flagella are an adaptation to scarce nutrient supplies,whereas eukaryotic flagella are designed to protect. 
D) Prokaryotic flagella do not require energy in the form of ATP as eukaryotic flagella do. 
A) Eukaryotic flagella undergo an undulating motion and are covered by a plasma membrane;prokaryotic flagella move by rotating and lack a plasma membrane. 
B) Prokaryotic flagella do not protrude outside the cell wall,whereas eukaryotic flagella are membrane-bound extensions of cytoplasm. 
C) Prokaryotic flagella are an adaptation to scarce nutrient supplies,whereas eukaryotic flagella are designed to protect. 
D) Prokaryotic flagella do not require energy in the form of ATP as eukaryotic flagella do.

Question 18

What can you infer about a high molecular weight protein that cannot be transported into the nucleus?

Accepted Answer

A) It is too large. 
B) It lacks a nuclear localization signal (NLS). 
C) It contains errors in its amino acid sequence. 
D) It lacks a signal sequence. 
A) It is too large. 
B) It lacks a nuclear localization signal (NLS). 
C) It contains errors in its amino acid sequence. 
D) It lacks a signal sequence.

Question 19

Scientists have found that polypeptides that are normally synthesized in the endoplasmic reticulum are about 20 amino acids longer when they are synthesized by ribosomes not attached to the endoplasmic reticulum.What is/are possible explanations for the greater length of these polypeptides?

Accepted Answer

A) The ribosomes that function as free ribosomes function differently than the ribosomes that are attached to the endoplasmic reticulum. 
B) The 20 amino acids serve as a signal sequence that directs the forming polypeptide to the endoplasmic reticulum,where they are cleaved off during processing. 
C) The 20-amino-acid sequence helps the endoplasmic reticulum package these proteins for shipping to the Golgi. 
D) The protein has a different function in the cytosol than in the endoplasmic reticulum. 
A) The ribosomes that function as free ribosomes function differently than the ribosomes that are attached to the endoplasmic reticulum. 
B) The 20 amino acids serve as a signal sequence that directs the forming polypeptide to the endoplasmic reticulum,where they are cleaved off during processing. 
C) The 20-amino-acid sequence helps the endoplasmic reticulum package these proteins for shipping to the Golgi. 
D) The protein has a different function in the cytosol than in the endoplasmic reticulum.

Question 20

Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport components.They set up microtubular tracks along which vesicles could be transported,and they added vesicles and ATP (because they knew the transport process requires energy).Yet,when they put everything together,there was no movement or transport of vesicles.What were they missing?

Accepted Answer

A) an axon 
B) contractile microfilaments 
C) endoplasmic reticulum 
D) motor proteins 
A) an axon 
B) contractile microfilaments 
C) endoplasmic reticulum 
D) motor proteins

Exam 7: Inside the Cell

Why is the smooth endoplasmic reticulum unable to synthesize proteins?

Actin filaments have polarity.This means that the two ends can be identified due to structural differences.The plus end is the end to which subunits are added more rapidly,or the end of polymerization.Which of the following would enable you to identify the plus end of actin filaments?

Which of the following statements represents a major difference between prokaryotic cells and eukaryotic cells?

Where are the proteins that will be exported (excreted)from the cell made?

Which of the following statements would best describe a cell that has an extensive area of smooth endoplasmic reticulum?

Which one of the following would you fail to find in a prokaryote?

Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein in the red blood cells (RBCs).What do you suspect is the consequence of such a defect?

Why are lysosomes considered part of the endomembrane system?

How is the structure of kinesin related to its function?

What is the function of the nuclear pore complex that is found in all eukaryotes?

Eukaryotic cells manufacture cytoskeletal proteins that help to maintain the cells' shapes and functions.What would you predict about these proteins?

Flagella and cilia bend or move,imparting mobility to cells.How do these structures move?

Amoebae move by crawling over a surface (cell crawling).Which one of the following processes is part of this type of movement?

You have a distant cousin,age 4,who is always tired and fatigued and is not able to play games and sports like other healthy children.He most likely has an enzyme deficiency or defect associated with which intracellular organelle?

Which of the following statements would be true about lysosomes that lack mannose-6-phosphate receptors?

What can you infer about a high molecular weight protein that cannot be transported into the nucleus?

Scientists have found that polypeptides that are normally synthesized in the endoplasmic reticulum are about 20 amino acids longer when they are synthesized by ribosomes not attached to the endoplasmic reticulum.What is/are possible explanations for the greater length of these polypeptides?

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

Lipids, membranes, and the First Cells

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green 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

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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