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INSTANT DOWNLOAD COMPLETE TEST BANK WITH ANSWERS

 

 

Biology Of Humans Concepts Applications And Issues 6th Edition By Judith – Test Bank

 

 

Sample  Questions

 

Biology of Humans: Concepts, Applications, and Issues, 6e (Goodenough)

Chapter 3  The Cell

 

3.1  Multiple Choice Questions

 

1) Which of the following is found in both eukaryotic and prokaryotic cells?

  1. A) ribosomes
  2. B) endoplasmic reticulum
  3. C) nucleus
  4. D) mitochondria

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.1

Section:  3.1

 

2) If natural selection would select against organisms with a nucleus, which one of the following organisms would survive and evolve?

  1. A) plants
  2. B) archaea
  3. C) protists
  4. D) fungi

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.1

Section:  3.1

 

3) You find a strange infection in your mouth and visit your dentist. The dentist said the new organism was prokaryotic because it had ________.

  1. A) circular DNA
  2. B) DNA in the nucleus
  3. C) relatively large cells
  4. D) membrane-bound organelles

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.1

Section:  3.1

 

4) The Mars rover Curiosity finds a living organism on the red planet. Scientists would know that it is eukaryotic and not prokaryotic if ________.

  1. A) it has membrane-bound organelles
  2. B) it has a cytoskeleton
  3. C) its diameter is 10 μm
  4. D) it has six internal membranes

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.1

Section:  3.1

5) A cell is limited in its size by ________.

  1. A) its ability to move waste material out
  2. B) its ability to move nutrients in
  3. C) its surface-to-volume ratio
  4. D) All of the above are correct.

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.2

Section:  3.2

 

6) A red blood cell has lost its nucleus to make more space for carrying oxygen. This is an example of ________.

  1. A) a prokaryotic cell
  2. B) a cell that is not living
  3. C) the relationship between structure and function
  4. D) a cell whose DNA is circular

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.3

 

7) The movement of water through a selectively permeable membrane from areas of high concentration to areas of low concentration until equilibrium is reached can be described as ________.

  1. A) diffusion
  2. B) active transport
  3. C) osmosis
  4. D) All of the above are true.

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

8) A form of diffusion in which the molecules pass through a protein instead of between the phospholipids is called ________.

  1. A) facilitated diffusion
  2. B) diffusion
  3. C) osmosis
  4. D) active transport

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

9) Which of these processes brings into the cell large macromolecules and particles by the formation of a vesicle in the outer membrane?

  1. A) facilitated transport
  2. B) endocytosis
  3. C) pinocytosis
  4. D) exocytosis

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

10) Which of these is most abundant in the plasma membrane?

  1. A) proteins
  2. B) carbohydrates
  3. C) cholesterol
  4. D) phospholipids

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

11) Calcium ions are normally in higher concentrations outside most living cells than within cells. Which of the following processes is most likely responsible for this condition?

  1. A) simple diffusion
  2. B) facilitated diffusion
  3. C) osmosis
  4. D) active transport

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

12) If a liver cell were to be placed in a beaker with a solution containing the same solute concentration as that found inside the cell, we would say that the beaker contained a(n) ________ solution.

  1. A) heterotonic
  2. B) hypertonic
  3. C) isotonic
  4. D) hypotonic

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

13) You have a bacterial infection. Your immune system will be able to distinguish this foreign invader from other cells by ________.

  1. A) recognizing cell adhesion molecules (CAMs)
  2. B) finding glycolipids on the plasma membrane
  3. C) identifying glycoproteins on the plasma membrane
  4. D) determining the presence or absence of a nucleus

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

14) When bacteria appear in tissues, a type of large cell engulfs and destroys them. Which process are these cells using to engulf the bacteria?

  1. A) exocytosis
  2. B) active transport
  3. C) pinocytosis
  4. D) phagocytosis

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.3

Section:  3.4

 

15) Which of the following is a membranous organelle that chemically modifies and ships proteins to other organelles or out of the cell?

  1. A) lysosome
  2. B) chloroplast
  3. C) mitochondria
  4. D) Golgi complex

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

16) Most of the energy used by the cell is converted to ATP in ________.

  1. A) lysosomes
  2. B) Golgi complexes
  3. C) nuclei
  4. D) mitochondria

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

17) Zara has worked for 40 years at a garden center, where she often potted plants. In the early days, she frequently worked with vermiculite, an asbestos-like material. Which organelles are most likely to have destabilized membranes as a result of exposure to vermiculite?

  1. A) nuclei
  2. B) mitochondria
  3. C) Golgi complexes
  4. D) lysosomes

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

18) Heart muscle works hard and therefore consumes much ATP. Which organelles would you expect to be especially numerous in the heart muscle cells?

  1. A) nuclei
  2. B) mitochondria
  3. C) Golgi complexes
  4. D) lysosomes

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

19) A reddish chemical, lipofuscin, is found in greater quantities in cells of older people than in those from younger people. This chemical should be broken down in the cells. Which specific type of organelle is not working as well in the seniors?

  1. A) lysosome
  2. B) mitochondrion
  3. C) nucleus
  4. D) rough endoplasmic reticulum

Answer:  A

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.4

Section:  3.5

 

20) Which of the following is not a membrane-bound organelle?

  1. A) mitochondrion
  2. B) cytoskeleton
  3. C) nucleus
  4. D) endoplasmic reticulum

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.5

 

21) Mitochondrial diseases ________.

  1. A) are very rare; only a couple of people are diagnosed per year
  2. B) are caused only by spontaneous mitochondrial DNA mutations
  3. C) cannot be inherited from the mother
  4. D) None of the above is true.

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

22) Some drugs used in chemotherapy stop cell division by affecting the cytoskeleton. The drugs would cause functional disabilities in which of the following?

  1. A) flagella
  2. B) cilia
  3. C) neither flagella nor cilia
  4. D) both flagella and cilia

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.6

 

23) Which of the following is true of both cilia and flagella?

  1. A) They are commonly found on cells of the respiratory tract.
  2. B) They are numerous and are short extensions.
  3. C) They move in a back-and-forth manner.
  4. D) They have a 9 + 2 pattern of microtubules.

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.6

 

24) Microfilaments are made of ________.

  1. A) actin
  2. B) tubulin
  3. C) intermediate proteins
  4. D) phospholipids

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.6

 

 

25) Cilia and flagella are both made of ________.

  1. A) actin
  2. B) tubulin
  3. C) intermediate proteins
  4. D) phospholipids

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.6

26) The virus that causes rabies travels up nerve cells to the brain and spinal cord. Which cell structures will allow the virus to move through the nerve cells?

  1. A) Golgi complexes
  2. B) nuclei
  3. C) microtubules
  4. D) pseudopods

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.5

Section:  3.6

 

27) From which of these phases of cellular respiration does the cell get the most ATP?

  1. A) glycolysis
  2. B) citric acid cycle
  3. C) transition reaction
  4. D) electron transport chain

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

28) Which of the following steps in normal cellular respiration ends with formation of water?

  1. A) glycolysis
  2. B) citric acid cycle
  3. C) electron transport
  4. D) fermentation

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

 

29) During a 5-mile run in the high Alps, where oxygen concentration is lower, your body will produce less ATP per molecule of glucose than after the same run near sea level, where there is plenty of oxygen to supply your muscle cells. Approximately how many more molecules of ATP will your muscle cells produce per molecule of glucose at the lower elevation than at the oxygen-scarce high elevation?

  1. A) 36
  2. B) 34
  3. C) 32
  4. D) 2

Answer:  B

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.6

Section:  3.7

30) If substantial lactic acid were found in a person’s bloodstream, which type of glucose breakdown is occurring?

  1. A) cellular respiration
  2. B) fermentation
  3. C) electron transport
  4. D) citric acid cycle

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

31) The first phase in normal cellular respiration and the only one occurring in the cytoplasm is called ________.

  1. A) the citric acid cycle
  2. B) glycolysis
  3. C) electron transport
  4. D) None of the above is correct.

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

 

3.2  Fill-in-the-Blank Questions

 

1) ________ are microscopic prokaryotes inhabiting, among other hostile places, hot springs and very salty waters.

Answer:  Archaea

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.1

Section:  3.1

 

2) The three types of microscopes used to look at cells and parts of cells are the transmission electron microscope, scanning electron microscope, and ________.

Answer:  light microscope

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.2

Section:  3.2

 

3) Certain molecules (called glycoproteins) are on the outer surface of the plasma membrane. They have the function of ________.

Answer:  cell recognition

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

4) Ricin is a potential chemical warfare agent that kills by disabling the ribosomes. With ricin poisoning, a cell would no longer be able to make ________.

Answer:  proteins

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

5) ________ is the ingestion of large molecules and foreign substances through the phospholipid membrane.

Answer:  Endocytosis

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

6) ________ are membrane proteins that help cells to stick to each other.

Answer:           CAMs (cellular adhesion molecules)

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

 

7) ________ is the process by which large molecules and cell products leave the cell through the phospholipid membrane.

Answer:  Exocytosis

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

8) Random movement from a region with higher concentration to a region with lower concentration in the cell is called ________.

Answer:  simple diffusion

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

9) Proteins are processed and packaged in the organelle known as the ________.

Answer:  Golgi complex

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

10) The organelle known as the ________ makes phospholipids.

Answer:  smooth endoplasmic reticulum

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

11) Cellular structures that function in movement and consist of numerous short hairlike extensions from the cell are called ________.

Answer:  cilia

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Section:  3.5

 

12) ________ is a metabolic process that creates ATP for the cell by the breakdown of glucose molecules. This process occurs in the cytoplasm.

Answer:  Glycolysis

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

13) Certain organisms break down glucose in the absence of oxygen. This process is called ________.

Answer:  fermentation

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

3.3  Matching Questions

 

Match each definition in the first column to the correct term in the second column.

 

  1. A) Cristae
  2. B) Electron transport chain
  3. C) Microtubules
  4. D) Glycolysis
  5. E) Flagella
  6. F) Plasma membrane
  7. G) Citric acid cycle
  8. H) ATP

 

1) Is produced along with water at the end of normal cellular respiration.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

2) The process of splitting glucose into two molecules of pyruvate without the use of oxygen.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

3) They serve as the working parts of cilia and flagella.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.6

 

4) A metabolic process that completes the oxidation of glucose, yields two molecules of ATP, and releases carbon dioxide as a waste product.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

5) A process by which the NADH and FADH pass their electrons through the inner membrane of the mitochondria, producing ATP and metabolic water.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

6) Cytoskeleton components that are composed of microtubules that move in a whiplike motion to propel the cell.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Section:  3.6

 

 

7) These form the inner membranes of the mitochondria and are the site for energy production in the electron transport chain.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.6

Section:  3.7

 

8) A cell structure that acts as a boundary between a cell and its environment.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.3

Section:  3.4

 

Answers: 1) H 2) D 3) C 4) G 5) B 6) E 7) A 8) F

 

3.4  Short Answer and Essay Questions

 

1) Mature red blood cells do not have a well-defined nucleus or other membrane-bound organelles. What is the advantage of this characteristic?

Answer:  By extruding its nucleus and most organelles, a red blood cell leaves more space for hemoglobin, the protein that transports oxygen.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.3

Global LO:  G1

Section:  3.3

 

2) If a new anesthetic were developed that entered the nerve cells efficiently, why would it be important for the substance to be lipophilic (to dissolve in lipids)?

Answer:  Only certain types of molecules can cross the cell membrane. Because this anesthetic is lipophilic, it can easily move through the phospholipid bilayer of the cell membrane.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.4

Global LO:  G2

Section:  3.4

3) Compare and contrast isotonic, hypotonic, and hypertonic solutions. What happens when a normal animal cell finds itself in any of the three kinds of solutions?

Answer:  Osmotic pressure forms in a cell when there is a difference in solute concentrations on either side of the membrane. There are three possible solutions within a cell. Isotonic solutions have equal osmotic pressure on both sides of a membrane, so there is no net movement of water across the membrane. A hypotonic solution has less osmotic pressure, or more water, than the solution across the membrane. A hypertonic solution has a greater osmotic pressure (less water). Cells in hypertonic solutions lose water, whereas cells in hypotonic solutions gain water.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.4

Global LO:  G4|G8

Section:  3.4

 

 

4) Compare and contrast passive and active transport mechanisms, and give an example of each.

Answer:  Passive transport involves the movement of molecules across a membrane along the concentration gradient without ATP. Examples of passive transport include simple diffusion, facilitated diffusion, and osmosis. Diffusion is the net movement of particles from regions of greater to lower concentration until equilibrium is reached. Facilitated diffusion is the movement of a substance from higher to lower concentration with aid from a membrane protein. Osmosis is the diffusion of water across a membrane from areas of higher to lower concentrations. Active transport requires the input of energy (ATP) for the movement of solutes, typically against the concentration gradient.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.4

Global LO:  G4|G8

Section:  3.4

 

5) We know that from their mother’s milk, infants gain proteins called antibodies that protect them from specific germs. We also know that proteins will eventually be broken down by a person’s digestive system. How is it that these antibodies can get into the bloodstream of the breast-feeding infant intact? Use only the information from this chapter.

Answer:  It appears that the child’s digestive system engulfs the proteins by the process called pinocytosis before the chemicals can be broken down.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.4

Global LO:  G2|G7

Section:  3.4

6) Maria, a volunteer firefighter in New Jersey, rushed along with the rest of her fire company to lower Manhattan on that awful morning of September 11, 2001. As they crossed over the Hudson into the city, they heard that the towers had collapsed, so they helped search through the rubble and dust from the buildings to find survivors. Maria has now developed serious health problems based on her exposure to the rubble and dust, which included asbestos and many other small particles. Which organ system and which organelle do you think are most likely failing in this brave woman’s body?

Answer:  Because Maria was exposed to many airborne particles within the rubble as well as inhaled the dust, it is likely that her respiratory system has been damaged. Lysosomes inside the cells cleaning the respiratory passages cannot break down asbestos. These small particles destabilize the membranes of the lysosomes, causing the release of enzymes in the respiratory tract and scarring of Maria’s lung tissue.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.5

Global LO:  G2|G5|G8

Section:  3.5

 

 

7) What are lysosomes, and how do they work in the cell?

Answer:  Lysosomes are membrane-bound organelles containing about 40 different digestive enzymes. The lysosomes digest bacteria as well as dispose of useless or worn-out parts of the cell.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.5

Global LO:  G8

Section:  3.5

 

8) Why might the lungs of smokers look dirtier than those of nonsmokers, assuming all other aspects of their lives are similar? What organelle is involved?

Answer:  The cilia in cells lining respiratory passages normally sweep debris from those tubes; however, in cigarette smokers, the cilia are immobilized. Therefore, the lungs of smokers would logically accumulate more airborne contaminants.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.6

Global LO:  G2|G7|G8

Section:  3.6

 

9) Compare the composition, structure, and function of cilia and flagella.

Answer:  Microtubules serve as the working parts of two types of cell extensions called cilia (singular, cilium) and flagella (singular, flagellum). Cilia are numerous, short extensions on a cell that move with the back-and-forth motion of oars. A flagellum resembles a whip and moves in an undulating manner. Cilia and flagella differ in length, number per cell, and pattern of movement. Nevertheless, they have a similar arrangement of microtubules at their core, which consists of nine pairs of microtubules arranged in a ring with two microtubules at the center.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  3.6

Global LO:  G2|G8

Section:  3.6

10) Briefly explain the differences between cellular respiration and fermentation. How do these processes differ in terms of energy output for the cell?

Answer:  Cellular respiration begins in the cytoplasm of a cell (glycolysis) and continues within the mitochondria (the transition reaction, citric acid cycle, and electron transport system). A total of 36 ATP molecules is produced by this metabolic pathway. Fermentation involves the breakdown of glucose in the cytoplasm (glycolysis), producing lactic acid in eukaryotes. Only two ATP molecules are produced in this pathway, both of which are generated in glycolysis. Cellular respiration requires oxygen; fermentation does not.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  3.7

Global LO:  G8

Section:  3.7

 

Biology of Humans: Concepts, Applications, and Issues, 6e (Goodenough)

Chapter 7  Neurons: The Matter of the Mind

 

7.1  Multiple Choice Questions

 

1) Which type of cell found in the nervous system is the most numerous?

  1. A) neuron
  2. B) neuroglial cell
  3. C) sensory cell
  4. D) Schwann cell

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

2) Leprosy destroys nerve tissue, so an afflicted person is likely to hurt his or her foot without even knowing it. Which types of neurons are likely to be affected?

  1. A) neuroglial cells
  2. B) motor neurons
  3. C) sensory neurons
  4. D) interneurons

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.1

Section:  7.1

 

3) Which type of neuron is found only in the brain and spinal cord?

  1. A) sensory neuron
  2. B) interneuron
  3. C) motor neuron
  4. D) glial cell

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

4) Which of the following parts of the nervous system is closest to a muscle?

  1. A) neuron
  2. B) interneuron
  3. C) motor neuron
  4. D) neuroglial cell

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

5) Muscle cells that are not exercised will atrophy, or shrink in size. Lou Gehrig’s disease affects nervous tissue but also causes muscle atrophy. What type of nerve cell must be affected to cause this muscle-wasting condition?

  1. A) interneurons
  2. B) sensory neurons
  3. C) neuroglial cells
  4. D) motor neurons

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.1

Section:  7.1

 

6) In saltatory conduction, nerve impulses jump from one exposed region of the axon to another. This exposed region is called the ________.

  1. A) motor end plate
  2. B) node of Ranvier
  3. C) Schwann cell gap
  4. D) interneurons

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

7) Inhaling or “huffing” is a way to achieve a high, usually by breathing in a fat-soluble substance. Which of the following structures would be most likely attacked first?

  1. A) myelin sheath
  2. B) axon
  3. C) neuron
  4. D) dendrite

Answer:  A

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.2

Section:  7.2

 

8) Multiple sclerosis is a disease in which the myelin sheath is destroyed. What will happen to nerve conduction speed in affected neurons?

  1. A) It will slow down dramatically.
  2. B) It will speed up dramatically.
  3. C) It will speed up just a little bit.
  4. D) There will be no effect.

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

9) Infants require many nutrients early in life, including lipids such as fats. A low-fat diet for infants is not recommended because, among other things, it can affect the development of the nervous system. Why does the developing nervous system need lipids?

  1. A) Glial cells need lipids to produce the myelin sheath.
  2. B) Fats are needed for energy because infants are often on a low-carbohydrate diet.
  3. C) Lipids are needed to produce the polypeptide neurotransmitters used by neurons.
  4. D) Fats are required to generate action potentials on nerve cells.

Answer:  A

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.2

Section:  7.2

 

10) When traveling down the neuron, which of the following parts of the neuron does the action potential pass through before the axon?

  1. A) glial cell
  2. B) dendrite
  3. C) synapse
  4. D) cell body

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.2

Section:  7.2

 

11) Which of these diseases involves the destruction of the myelin sheath on certain neurons within the brain and spinal cord?

  1. A) depression
  2. B) Alzheimer’s disease
  3. C) Parkinson’s disease
  4. D) multiple sclerosis

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

12) A new drug interferes with the function of the dendrites of a neuron. What will happen to this neuron?

  1. A) The neuron will continuously send signals.
  2. B) The neuron cannot be stimulated to send a signal along its axon.
  3. C) The neuron will die off.
  4. D) The neuron will sometimes send signals and will sometimes not send signals.

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

13) Which one of the following ions outside the neuron would make it very difficult for a depolarization to occur?

  1. A) potassium
  2. B) sodium
  3. C) chloride
  4. D) manganese

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.3

Section:  7.3

 

14) The specialized membrane proteins that actively transport sodium and potassium ions across the plasma membrane are known as the ________.

  1. A) sodium-chloride pump
  2. B) sodium-manganese pump
  3. C) sodium-potassium pump
  4. D) sodium pump

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

15) A nerve impulse does not vary in intensity with regard to the strength of the stimulus. What do we call this phenomenon?

  1. A) resting membrane potential
  2. B) refractory period
  3. C) all-or-nothing principle
  4. D) graded response

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

16) Sodium and potassium ions cross the neuron’s membrane to cause which of the following processes?

  1. A) action potential
  2. B) passive transport
  3. C) refractory period
  4. D) transmission

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

17) A neuron’s membrane that maintains a charge difference across its surface in which the inside is more negative than the outside is called ________.

  1. A) graded potential
  2. B) resting potential
  3. C) action potential
  4. D) summation

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

18) Some drugs modulate the activity of ion channels. For example, Novocain somewhat inhibits the opening of sodium channels. What happens to the threshold of a sensory neuron if this drug is used?

  1. A) It will take less stimulation to reach threshold.
  2. B) It will take more stimulation to reach threshold.
  3. C) Threshold will not change.
  4. D) The nerve will not function and will die off.

Answer:  B

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.3

Section:  7.3

 

19) Ouabain is a chemical used on poison arrows in Africa. It works by inhibiting the sodium-potassium pump. What effect does this chemical have on an action potential?

  1. A) It prevents the stimulation of an action potential by removing sodium from the cell.
  2. B) It immediately causes an action potential to be generated.
  3. C) There is no direct effect because the pump is used to maintain ion distributions, not to cause an action potential.
  4. D) It causes the release of a neurotransmitter that causes an action potential.

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.3

Section:  7.3

 

20) Which of the following is a chemical signal that diffuses across the gap between adjacent neurons to convey a message to the next cell?

  1. A) neurotransmitter
  2. B) synapse
  3. C) dendrite
  4. D) action potential

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

21) The combined effects of inhibitory and excitatory effects on a postsynaptic cell will decide whether that cell generates an action potential. This principle is called ________.

  1. A) threshold
  2. B) internalization
  3. C) summation
  4. D) potentiation

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

22) Which of the following is a neurotransmitter that triggers a contraction of a voluntary muscle?

  1. A) synapse
  2. B) action potential
  3. C) sodium
  4. D) acetylcholine

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

23) Your classmate does not have much muscle strength. Her doctor says she has an autoimmune disease, but you didn’t quite catch the name the physician gave for the illness. Based on what you have learned, what do you think the diagnosis is?

  1. A) Alzheimer’s disease
  2. B) schizophrenia
  3. C) senility
  4. D) myasthenia gravis

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.4

Section:  7.4

 

24) Which neurotransmitter appears to be associated with an energizing “good” feeling and is essential in hunger, thirst, and sex drive?

  1. A) dopamine
  2. B) serotonin
  3. C) norepinephrine
  4. D) synapse

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

25) Which neurotransmitter may function to regulate emotions and is involved in pathways that control complex movements?

  1. A) dopamine
  2. B) serotonin
  3. C) norepinephrine
  4. D) synapse

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

26) Prior to their release, where are the special chemicals called neurotransmitters stored in a neuron?

  1. A) axon
  2. B) synaptic knob
  3. C) dendrites
  4. D) cell body

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

27) You might have been accidentally exposed to an insecticide while working in a citrus grove. What symptoms of poisoning would you watch for?

  1. A) depression
  2. B) Alzheimer’s disease
  3. C) muscle tremors
  4. D) excessive urination

Answer:  C

Bloom’s Taxonomy:  Synthesis/Evaluation

Learning Outcome:  7.4

Section:  7.4

 

28) Prescription drugs such as Prozac help maintain higher levels of serotonin in the brain. What effect will this have on an individual?

  1. A) It will act as an antidepressant because a lack of serotonin is considered a cause of depression symptoms.
  2. B) It will act to suppress impulsive behavior because too much serotonin causes children to act out.
  3. C) It will cause a patient to be sleepy because serotonin is essential to a good night’s sleep.
  4. D) It will cause tetany due to an overproduction of acetylcholine.

Answer:  A

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.4

Section:  7.4

 

7.2  Fill-in-the-Blank Questions

 

1) ________ is the name given to the motor neurons that carry information away from the brain or spinal cord.

Answer:  Efferent

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

2) A(n) ________, or afferent, neuron conducts information toward the brain and spinal cord.

Answer:  sensory

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

3) ________ is the name of the cell that wraps around the axon, forming the myelin sheath.

Answer:  Schwann cell

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

4) Axons and dendrites of individual neurons, arranged in bundles and covered by connective tissue, make up ________.

Answer:  nerves

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

5) The jumping of a nerve impulse from one node of Ranvier to the next is known as ________.

Answer:  saltatory conduction

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

6) ________ are numerous short, branching projections from the neuron that create a huge surface for receiving signals from other cells.

Answer:  Dendrites

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

7) The neuron requires a certain level of depolarization of its membrane in order to generate an action potential. This level of depolarization is known as the ________.

Answer:  threshold

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

8) During an action potential, the ________ ions rush into the axon.

Answer:  sodium

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

9) Immediately after an action potential occurs, the sodium channels close and cannot be reopened. What is this period called?

Answer:  refractory period

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

10) The neuron that releases neurotransmitters is known as ________, while the neuron that receives the neurotransmitters is knows as ________.

Answer:  presynaptic; postsynaptic

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

11)

Look at the accompanying figure. In Step 1 ________ ions enter the neuron, while in Step 2 ________ ions leave the neuron.

Answer:  sodium; potassium

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

 

12) ________ is a progressive brain disease in which the dopamine-producing neurons in the movement control center of the brain die.

Answer:  Parkinson’s disease

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

13) ________ involves an insufficient amount of several neurotransmitters, such as serotonin, dopamine, and norepinephrine, for extended periods of time.

Answer:  Clinical depression

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

14) The synaptic ________ is the narrow space between two neurons.

Answer:  cleft

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

15) The enzyme that removes the neurotransmitter acetylcholine from synapses after it has been released is known as ________.

Answer:  acetylcholinesterase

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

16) ________ is a neurotransmitter released at every neuromuscular junction (the junction of a motor neuron and a skeletal muscle cell), where it triggers contraction of voluntary (skeletal) muscles.

Answer:  Acetylcholine

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

7.3  Matching Questions

 

Match each definition in the first column to the correct term in the second column.

 

  1. A) Inhibitory synapse
  2. B) Synapse
  3. C) Sensory neuron
  4. D) Synaptic knobs
  5. E) Dendrite
  6. F) Axon
  7. G) Motor neuron
  8. H) Interneurons
  9. I) Ion channels
  10. J) Excitatory synapse

 

1) Synapse in which neurotransmitters decrease the chance of an action potential on the postsynaptic cell.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.4

Section:  7.4

 

2) Synapse in which neurotransmitters allow sodium to enter the postsynaptic cell.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

3) A specific type of neuron that conducts information toward the brain and spinal cord from a sensory receptor.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

4) The junction between a neuron and another cell.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

5) The short branching projections of a neuron, which provide surface area for sending and receiving signals from other cells.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

6) Specific neurons that carry information away from the brain and spinal cord to an effector such as a muscle or a gland.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

7) Membrane proteins that allow specific charged molecules to pass through from one side of the membrane to the other.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.3

Section:  7.3

 

8) Part of the neuron where neurotransmitters are released.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.4

Section:  7.4

 

9) A single, long extension of a neuron’s cell body that functions to transmit an incoming message or impulse.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Section:  7.2

 

10) Association neurons that are located between the sensory and motor neurons, where they integrate or interpret the sensory signals.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.1

Section:  7.1

 

Answers: 1) A 2) J 3) C 4) B 5) E 6) G 7) I 8) D 9) F 10) H

 

7.4  Short Answer and Essay Questions

 

1) Compare and contrast the sensory neurons, motor neurons, and interneurons.

Answer:  All three have the generalized components of a neuron, such as the cell body, dendrites, and so on. However, sensory neurons conduct information toward the brain and spinal cord from the sensory receptors that gather information within and around the body. By contrast, motor neurons carry information away from the brain and spinal cord to an effector. Association neurons, or interneurons, can be found between sensory and motor neurons within the brain or spinal cord. These neurons are responsible for the integration or interpretation of sensory signals and the response to these signals.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.1

Global LO:  G8

Section:  7.1

 

 

2) Explain the anatomy of a typical neuron.

Answer:  Dendrites are numerous short, branching projections from a neuron that receive information from other neurons or from the environment. The cell body controls the neuron’s metabolic activities and integrates input from other neurons. The axon conducts the nerve impulses away from the cell body. Neurotransmitters are released at synaptic knobs.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Global LO:  G8

Section:  7.2

 

3) What is the function of the myelin sheath in the nervous system?

Answer:  The myelin sheath serves to insulate axons of neurons in the brain and spinal cord along with axons outside the brain and spinal cord. It is composed of Schwann cells outside the central nervous system (CNS). The Schwann cells wrap around an axon many times to prevent messages from short-circuiting between neurons.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  7.2

Global LO:  G8

Section:  7.2

 

4) Some nerves are myelinated, and others are not. Myelinated nerves send signals faster than unmyelinated neurons. Draw two neurons of equal length, and wrap segments of myelin along one. Be careful to leave spaces for the nodes of Ranvier. Now, measure the exposed axons of each, and total up the distance. Describe why the myelinated neurons send signals faster.

Answer:  It should be apparent from the drawing that myelinated neurons have less exposed axon length; thus, signals travel faster as they jump from one node to the next.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.2

Global LO:  G4|G8

Section:  7.2

5) If a drug had the side effect of destroying dopamine-producing neurons, what effect would this have on a person?

Answer:  The individual would probably start to show signs of Parkinson’s disease. Signs include a shuffling walk, hunched posture, and possible involuntary shaking.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.4

Global LO:  G5|G8

Section:  7.4

 

 

6) What are some of the dangers associated with the use of organophosphate pesticides that might be of concern for humans? (Organophosphates inhibit acetylcholinesterase.) What are some ethical concerns related to their use?

Answer:  There are many insecticides that prevent insect pests from damaging favorable plants or household foods. The organophosphate insecticides kill insects by inhibiting acetylcholinesterase, the enzyme that degrades acetylcholine. This causes acetylcholine to accumulate and continuously stimulate in the synapse. These pesticides have a similar effect on humans.

 

The following are some of the ethical concerns: (1) Organophosphates could be used against humans in warfare. (2) Organophosphates could pose a threat to wildlife, including “good” insects such as bees, if not applied carefully. (3) These toxins could be used in homicides and suicides. (4) Accidental poisoning of farm workers and others exposed to these pesticides kills 500,000 people annually worldwide.

Bloom’s Taxonomy:  Synthesis/Evaluation

Learning Outcome:  7.4

Global LO:  G2|G5|G7|G8

Section:  7.4

 

7) Tay-Sachs disease is a genetic disorder in which fat deposits build up in nerve cells of the brain, leading to a slow loss of function. Because this disease usually strikes children under 1 year of age, the symptoms are not immediately apparent. Think about the symptoms that this condition would cause. List some that you think are possible. What would be the inevitable end result as the disease progresses?

Answer:  The disease would interfere with neuron function in the brain. Because very young children don’t speak, verbal communication is not a reliable measure of the illness. The most noticeable symptoms would be loss of motor function, difficulty swallowing, or inability to see or move around in response to stimuli. Eventually, motor function will be impaired to the point that the child will be unable to breathe. In the end, the disease is fatal.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.3

Global LO:  G5|G7|G8

Section:  7.3

 

8) Potassium ions are important in the resting membrane potential and the action potential of the nerve and to the contraction of muscle cells. The concentration gradient of potassium ions is critical to both. An excess of potassium outside a neuron or muscle cell would negate the concentration gradient. What would happen if the heart were injected with massive amounts of potassium? Explain your answer.

Answer:  Potassium ions added to the exterior of a cell would disrupt the resting membrane potential because they would not “leak” in the correct direction. During the resting potential, there are more potassium ions inside of the cell; during the action potential, potassium leaks out of the cell. An action potential could be initiated as sodium rushes into the cell, but another one could not be generated.

Bloom’s Taxonomy:  Synthesis/Evaluation

Learning Outcome:  7.3

Global LO:  G7|G8

Section:  7.3

 

9) In the disease myasthenia gravis, the immune system attacks the receptors for the neurotransmitter acetylcholine. A drug is used to inhibit the enzyme acetylcholinesterase, which normally removes the neurotransmitter. This improves the condition of the patient. How does this work?

Answer:  If a person with this disease has fewer receptors for acetylcholine, it would help to inhibit the breakdown of the neurotransmitter in the synapse. Increasing the concentration of the neurotransmitter in the synapse could increase the likelihood that some of the neurotransmitter will bind with the receptors.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  7.4

Global LO:  G7|G8

Section:  7.4

 

Biology of Humans: Concepts, Applications, and Issues, 6e (Goodenough)

Chapter 13a  Special Topic: Infectious Disease

 

13a.1  Multiple Choice Questions

 

1) Cholera is spread by contaminated food and water. The bacterium kills by changing the permeability of the cells of the large intestine. Which therapy would give the best chance of saving a person with cholera, given the information in this chapter?

  1. A) chemotherapy
  2. B) radiation
  3. C) fluid replacement
  4. D) surgery

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  13a.1

Global LO:  G7

Section:  13a.1

 

2) Bacteria that normally live on or in the body and prevent other bacteria from becoming too numerous are referred to as ________.

  1. A) bacterial toxins
  2. B) beneficial bacteria
  3. C) pathogens
  4. D) parasitic

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

3) A pathogen is a disease-causing organism, but not all pathogens are alike. Some pathogens are more dangerous than others. When describing the relative ability of a pathogen to cause disease, we are considering its ________.

  1. A) pathogenicity
  2. B) virulence
  3. C) infectivity
  4. D) emergence

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

 

4) Antibiotics stop working effectively when antibiotic resistance occurs. Which of the following does not contribute to an increase in antibiotic resistance?

  1. A) antibiotics in animal feed
  2. B) stopping antibiotics as soon as you feel better
  3. C) increase of good bacteria in the body
  4. D) taking antibiotics for viral diseases

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Global LO:  G5

Section:  13a.1

5) Athlete’s foot is caused by a(n) ________.

  1. A) insect
  2. B) fungus
  3. C) bacterium
  4. D) virus

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

6) Vibrio cholerae causes Asiatic cholera. It has a corkscrew shape, so we would say it has this form.

  1. A) clostridia
  2. B) bacillus
  3. C) coccus
  4. D) spirillum

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

7) What is the most effective way of killing Staphylococcus in the food you are preparing?

  1. A) Nothing; this organism never is spread in food.
  2. B) Mix antibiotics in with the food.
  3. C) Cook the food thoroughly.
  4. D) Use a good antiseptic on the food itself before preparing it.

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  13a.1

Global LO:  G5

Section:  13a.1

 

 

8) Product recalls on frozen hamburger are not uncommon during any given year. The meatpacking industry can experience problems when processing centers accidentally introduce this fecal bacterium into ground meat. Which organism is commonly found to be the culprit?

  1. A) Clostridium
  2. B) coli
  3. C) Streptococcus
  4. D) Staphylococcus

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.2

Global LO:  G5

Section:  13a.2

9) Which of the following characteristics of a medicine might be effective in treating a herpes simplex (a virus, not a bacteria) infection with as little harm to the patient as possible?

  1. A) blocking cell wall synthesis
  2. B) stopping cilia activity
  3. C) preventing capsid formation
  4. D) halting membrane formation

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

10) Ringworm is caused by a(n) ________.

  1. A) insect
  2. B) fungus
  3. C) bacterium
  4. D) virus

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

11) A virus differs from a bacterium in that a virus ________.

  1. A) develops resistance to antibiotics
  2. B) is not a living organism
  3. C) causes pneumonia
  4. D) does not have DNA or RNA

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

 

12) A camping party got lost in the wilderness for several days. They had sufficient food but misplaced their matches and could drink only the water from the clear lakes and streams in the area without boiling it. Very quickly everyone developed diarrhea that lasted the entire 8 days until they were rescued. Which type of pathogen was probably responsible?

  1. A) protozoan
  2. B) fungus
  3. C) prion
  4. D) vector

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Global LO:  G7

Section:  13a.1

13) A gentleman noticed a rash, forming a target-like design, on his arm. Subsequently, he developed pain and later arthritis. The bacterium that caused his condition was most likely spread by ________.

  1. A) a mosquito
  2. B) unprotected sex
  3. C) uncooked food
  4. D) a tick

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  13a.2

Global LO:  G2

Section:  13a.2

 

14) A disease or condition with clinically distinct symptoms whose incidence has increased, especially in the past two decades, is called ________.

  1. A) emerging
  2. B) reemerging
  3. C) stagnating
  4. D) declining

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.3

Section:  13a.3

 

 

13a.2  Fill-in-the-Blank Questions

 

1) A(n) ________ is a global outbreak of disease.

Answer:  pandemic

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.3

Section:  13a.3

 

2) A(n) ________ is an animal that carries a disease from one host to another.

Answer:  vector

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.2

Section:  13a.2

 

3) ________ are disease-causing organisms that invade a person’s body.

Answer:  Pathogens

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

4) Infectious proteins that are heat resistant and that cannot be destroyed by ultraviolet light or most chemicals are known as ________.

Answer:  prions

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

5) ________ are made by certain pathogens such as Staphylococcus, Salmonella, Escherichia coli, and Clostridium botulinum. These substances often travel in the bloodstream and cause disease symptoms.

Answer:  Bacterial toxins

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

6) Bacteria reproduce rapidly. It is possible for a few bacteria to grow in numbers sufficient to spoil milk left out overnight. The process by which bacteria reproduce is called ________.

Answer:  binary fission

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

 

 

13a.3  Short Answer and Essay Questions

 

1) Explain how antibiotics are used to treat bacterial infections. What are some of the problems concerning the use of these drugs?

Answer:  Antibiotics work in a variety of ways, including inducing the bacterial cells to burst. Some antibiotics target the cell walls of bacteria; because animal cells lack cell walls, these antibiotics won’t kill human cells. Other antibiotics interfere with bacterial protein synthesis; this works because ribosome structure is different in bacteria and animal cells. A major problem is the development of bacterial strains that are resistant to antibiotics. This results from the overuse and misuse of antibiotics.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Global LO:  G5|G7|G8

Section:  13a.1

 

2) A new antibiotic is introduced that will destroy only organisms lacking a nuclear membrane. A dispute develops over its safety when used in people. What arguments would you use in this discussion?

Answer:  Human cells have nuclear membranes, so the antibiotic will not directly harm people. However, there are many beneficial bacteria (lacking nuclear membranes) that this new antibiotic might well wipe out. This may produce indirect harm to humans.

Bloom’s Taxonomy:  Synthesis/Evaluation

Learning Outcome:  13a.1

Global LO:  G2|G7

Section:  13a.1

 

3) Tetracycline antibiotics are frequently included in commercial poultry feed. Why is the practice unwise for human health in the long run?

Answer:  This use of an antibiotic hastens the day when potentially devastating pathogenic bacteria evolve natural resistance to the antibiotic.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.1

Section:  13a.1

4) In some cultures, parts of the central nervous system (e.g., brains) of cattle are popular foods. Predict the issues that might arise from this practice.

Answer:  According to the chapter, transmissible spongiform encephalopathies are associated with the brains of certain livestock, including cattle. The condition arises from prions, and the prion responsible for mad cow disease is thought to cause one form of Creutzfeldt-Jakob disease in humans.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  13a.1

Global LO:  G5

Section:  13a.1

 

 

5) Given the information in this chapter, why do you suppose that the rabies virus attacks mammal nervous systems but not those of crocodiles?

Answer:  The cells of the crocodile nervous system clearly have different receptors on their surfaces from those found on the cells of mammals. The molecules on the surface of the rabies virus would not fit into the receptors found on the surface of crocodile cells but would fit into those on the surface of mammal cells.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  13a.1

Global LO:  G2

Section:  13a.1

 

6) Developers wish to build a road through an isolated area where few people have ever visited before. The proposed route is wet and warm, with many species of wild rodents and other mammals. What issues concerning disease might this route raise?

Answer:  People will come in contact with ticks and other blood-sucking vectors and then may fall victim to some unexpected infectious diseases. Wild animals can serve as reservoirs of pathogens that can move to humans. Additionally, the human activity along the road may chase away predators that would have kept the rodent population in check. Finally, the number of species of wild mammals is a key factor in determining where new infectious diseases will emerge.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.3

Global LO:  G2|G7

Section:  13a.3

 

7) Lyme disease is caused by a bacterium found in the bloodstream of small woodland rodents such as mice or chipmunks and also found occasionally in deer. Yet humans get this disease without coming into direct contact with either rodents or deer. Explain the concept of a biological vector, and discuss how humans contract Lyme disease.

Answer:  Although the bacterium that causes Lyme disease is found in animals, it can be transmitted to humans even if the animal is not present. Small external parasites called ticks bite the animal host and pick up the microbes from the bloodstream. Then they may jump on a human who is passing by and bite the person. This bite transmits the bacterium from the tick to the human.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  13a.2

Global LO:  G8

Section:  13a.2

 

Biology of Humans: Concepts, Applications, and Issues, 6e (Goodenough)

Chapter 21  DNA and Biotechnology

 

21.1  Multiple Choice Questions

 

1) Which of the following is a method of gene amplification that involves complementary primers and uses heat to unzip DNA to make multiple copies of a particular gene?

  1. A) vector
  2. B) polymerase chain reaction
  3. C) sticky ends
  4. D) recombinant

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

2) In which part of the molecule does tRNA pair with mRNA?

  1. A) rRNA
  2. B) codon
  3. C) anticodon
  4. D) gene

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

3) Which of the following brings tRNA with an amino acid close enough to mRNA to permit interaction and the assembly of amino acids to form a protein?

  1. A) DNA polymerase
  2. B) RNA polymerase
  3. C) ribosome
  4. D) mRNA

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

4) Segments of DNA that increase the rate of transcription of certain genes are known as ________.

  1. A) enhancers
  2. B) polymerases
  3. C) short tandem repeats
  4. D) introns

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.5

Section:  21.5

5) A chemical that delivers amino acids one at a time in the ordered sequence specified by the mRNA strand is called ________.

  1. A) DNA
  2. B) tRNA
  3. C) rRNA
  4. D) mRNA

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

6) This technique has thousands of DNA sequences on a slide and is used to determine which are active at the time.

  1. A) microarray
  2. B) PCR
  3. C) recombinant DNA
  4. D) translation

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.7

Section:  21.7

 

7) This rare condition was the first to be experimentally treated with gene therapy.

  1. A) sickle-cell anemia
  2. B) Down syndrome
  3. C) SCID
  4. D) AIDS

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

8) The process of using each strand of a DNA molecule as a template to form a new strand is called ________.

  1. A) semiconservative replication
  2. B) conservative replication
  3. C) transcription
  4. D) translation

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.1

Section:  21.1

 

 

9) If a mutation occurred in this area, it would not directly change the specific placement of an amino acid in the resulting polypeptide.

  1. A) gene
  2. B) codon
  3. C) exon
  4. D) intron

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3b

Section:  21.3

10) Which of the following is a process in translation in which tRNA molecules deliver amino acids in the correct sequence, causing peptide bonds to form and increasing the length of the polypeptide chain?

  1. A) initiation
  2. B) elongation
  3. C) termination
  4. D) transcription

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

11) The base sequences that are left behind after the introns have been spliced out by enzymes are the ________.

  1. A) genes
  2. B) anticodons
  3. C) exons
  4. D) phosphates

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

12) Which of the following is the signal that functions to begin transcription and consists of a sequence on the DNA?

  1. A) mRNA
  2. B) promoter
  3. C) vector
  4. D) exon

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

 

13) The process in which the mRNA, tRNA, and ribosomal subunits come together during translation is called ________.

  1. A) initiation
  2. B) elongation
  3. C) termination
  4. D) deletion

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

14) The following is a part of a gene sequence: ATCAGC. What would be the resulting product of transcription?

  1. A) TAGTCG
  2. B) UAGUCG
  3. C) GACGTC
  4. D) CUGCUA

Answer:  B

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.3a

Section:  21.3

 

15) A tRNA with a long chain of amino acids is released from the ribosome because the stop codon does not correspond with a particular anticodon that causes the tRNA to fall off, leaving only the polypeptide chain. This process is called ________.

  1. A) initiation
  2. B) elongation
  3. C) termination
  4. D) deletion

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

16) The extra sequences of nucleotides that are excised out of the mRNA prior to leaving the nucleus are called ________.

  1. A) exons
  2. B) vestigial sequences
  3. C) tRNA
  4. D) introns

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

 

17) Which of the following uses patterns of STR fragments that have been cut by restriction enzymes and sorted by size?

  1. A) DNA fingerprinting
  2. B) DNA sequencing
  3. C) cloning
  4. D) genetic engineering

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

18) Which chemical carries the DNA’s instructions for synthesizing a particular protein from the nucleus to the cytoplasm?

  1. A) transfer RNA
  2. B) messenger RNA
  3. C) RNA transcriptase
  4. D) ribosomal RNA

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

19) Which process converts the nucleotide language of mRNA into the amino acid language of a protein?

  1. A) DNA replication
  2. B) transcription
  3. C) translation
  4. D) meiosis

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

20) Why are the complementary base-pairing rules so important when a cell needs to copy its DNA?

  1. A) The cells need both strands to be accurate because each strand codes for one half of the gene.
  2. B) As long as there is one strand, a copy can be made by following the pairing rules.
  3. C) Unless the bases pair up correctly, the DNA strand can break apart.
  4. D) Transcription cannot proceed unless the pairs are in the proper sequence.

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.2

Section:  21.2

 

 

21) Why do transcription and translation take place in two different locations?

  1. A) DNA is located in the nucleus, whereas the ribosomes needed for translation are not in the nucleus.
  2. B) DNA is located in the nucleus, whereas the ribosomes needed for translation are found outside the cell.
  3. C) DNA is located in the nucleus, whereas the ribosomes needed for transcription are found outside the cell.
  4. D) Translation takes place in the nucleus, whereas the DNA is located elsewhere.

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

22) Genes are really just segments of DNA in patterns of As, Ts, Gs, and Cs. How does an RNA polymerase “know” where to start transcribing at the beginning of a particular gene?

  1. A) The polymerase finds the end of the previous gene and copies past that point.
  2. B) The polymerase starts transcribing anywhere because the beginning point counts only during translation.
  3. C) It looks for a specific promoter region that marks the beginning of a gene.
  4. D) RNA polymerase does not know, so it has to rely on the ribosome to help it start at the correct place.

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

23) If there are 64 potential codons that code for various amino acids but only about 20 specific amino acids, what must be true about the genetic code?

  1. A) Most of the codons are not used.
  2. B) There are two codons for each amino acid, and the rest are stop codons.
  3. C) All are used, but bacteria and plants each have 20 different amino acids.
  4. D) Multiple codons code for the same amino acid.

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

 

24) DNA fingerprinting is now widely used to tie a particular suspect to the DNA samples found at a crime scene. What benefits can be derived from this technology in fighting crime?

  1. A) “Persons of interest” can be excluded more rapidly as suspects, so police can focus on other leads.
  2. B) A jailed convict can be proven to have no connection to evidence found at a crime scene.
  3. C) Solid matches can aid a district attorney’s case in proving guilt to a jury.
  4. D) All of the above are true.

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.6

Section:  21.6

 

25) The genetic code works only because each codon is read in a specific manner that results in the correct amino acid being placed in that particular spot. What physically places each amino acid by matching up the correct codon?

  1. A) tRNA
  2. B) mRNA
  3. C) DNA
  4. D) rRNA

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

26) Point mutations can occur in any given cell type, but they mostly affect only that one cell and cells produced by it. What cell type, if mutated, would allow the mutation to be passed on to family members for generations?

  1. A) glial cells, such as those that produce a myelin sheath
  2. B) skin cells
  3. C) white blood cells
  4. D) gametes, such as an egg or sperm

Answer:  D

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3b

Section:  21.4

 

27) The p53 gene is a tumor-suppressing gene that prevents damaged cells from undergoing cell division. If this gene ceases to function due to a mutation, what will happen to the cell?

  1. A) Tumors will be suppressed.
  2. B) The cell will die.
  3. C) Uncontrolled cell division will occur.
  4. D) The cell will be prevented from undergoing division.

Answer:  C

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.4

Section:  21.4

 

28) UV rays from the sun cause a specific type of improper base pairing called a thymine dimer. If a cell cannot correct this problem, the section of DNA can be removed, causing a deletion of several nucleotides. What will this cause?

  1. A) A point mutation forms that leads to a change in one amino acid.
  2. B) A point mutation forms that leads to changes in a handful of amino acids.
  3. C) The codons shift by one letter, and all the codons before the mutation are changed.
  4. D) The codons could shift by one letter, and all the codons after that point would be off.

Answer:  D

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.4

Section:  21.4

 

29) A new antibiotic is developed that interferes with the way tRNA fits into bacterial ribosomes. How would this kill the bacteria?

  1. A) The bacteria would be unable to produce necessary enzymes to carry out basic metabolism.
  2. B) The tRNA would be unable to carry out transcription.
  3. C) Ribosomes would not be able to produce mRNA, and cell functions would halt.
  4. D) tRNA would not unwind the DNA to allow DNA polymerase to copy it; thus, cell division would stop.

Answer:  A

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.3a

Section:  21.3

30) In gene expression, ________.

  1. A) DNA directs the synthesis of a polypeptide that directs the synthesis of RNA
  2. B) RNA determines the sequence of DNA, which directs the synthesis of polypeptides
  3. C) DNA directs the synthesis of RNA that directs the synthesis of a polypeptide
  4. D) polypeptides direct the synthesis for both RNA and DNA

Answer:  C

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

31) A goal of genomics is to ________.

  1. A) understand the mechanisms that control gene expression
  2. B) provide a way to produce large quantities of a particular gene product
  3. C) manipulate genetic material for human purposes
  4. D) regulate how genes are expressed without changing the protein they encode

Answer:  A

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.7

Section:  21.7

 

 

32) Many factors control the activity of genes. The array of chemicals that is responsible for turning a gene “on” is known as the ________.

  1. A) genetic engineer
  2. B) epigenome
  3. C) fingerprint
  4. D) recombinant gene

Answer:  B

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

21.2  Fill-in-the-Blank Questions

 

1) Translation occurs at the ________ in the cell.

Answer:  ribosome

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

2) A(n) ________ is composed of one sugar (deoxyribose or ribose), one phosphate, and one nitrogenous base.

Answer:  nucleotide

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.1

Section:  21.1

 

3) ________ is attached to a specific amino acid and transports it to the appropriate region of mRNA.

Answer:           Transfer RNA (tRNA)

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

4) The end product of transcription is the production of a(n) ________.

Answer:  mRNA

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

5) ________ are small pieces of DNA separate from the bacterial chromosome.

Answer:  Plasmids

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

 

6) The ________ is used to convert the linear sequences of bases in DNA to the sequence of amino acids in proteins.

Answer:  genetic code

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

7) Changes in the DNA are called ________.

Answer:  mutations

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3b

Section:  21.4

 

8) If you could neither synthesize nor acquire deoxyribose in any way, you could not make the nucleic acid ________.

Answer:  DNA

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.1

Section:  21.1

 

9) The amount of DNA can be increased when primers are heated with a mix of the original small amount of DNA, DNA polymerase, and nucleotides in the process known as ________.

Answer:           PCR (polymerase chain reaction)

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

10) The gene for one form of hemophilia is added to a harmless virus, and then the virus is given to someone with the hereditary disease. The virus is acting as a(n) ________.

Answer:  vector

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.6

Section:  21.6

 

11) RNA usually is ________ stranded.

Answer:  single

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

12) The manipulation of genetic material for human purposes, the practice of ________, began almost as soon as we began to understand the language of DNA.

Answer:  genetic engineering

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

13) The nitrogenous base found in RNA but not DNA is ________.

Answer:  uracil

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

14) A group of identical organisms that are all descendants from a single ancestor is known as a(n) ________.

Answer:  clone

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

15) If a double-stranded DNA has 20% adenine, then it will have ________ % cytosine.

Answer:  30

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.2

Global LO:  G4

Section:  21.2

 

16) DNA methylation and histone acetylation are considered two ________ processes.

Answer:  epigenetic

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

21.3  Matching Questions

 

Match each definition in the first column to the correct term in the second column.

 

  1. A) Thymine
  2. B) DNA polymerases
  3. C) RNA polymerase
  4. D) Codons
  5. E) Guanine
  6. F) Gene therapy
  7. G) Epigenetics
  8. H) Biotechnology
  9. I) Genome

 

1) The alteration of gene activity without DNA sequence change.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

2) The science of making a living cell perform a task considered useful by humans in a controlled way.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

3) The RNA “words” are called this.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

4) The process of replacing a faulty gene with healthy functional genes.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Section:  21.6

 

5) An enzyme that binds with the promoter on DNA and then synthesizes mRNA.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.3a

Section:  21.3

 

6) According to base-pairing rules, adenine will pair only with this.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.1

Section:  21.1

 

7) An individual’s complete set of DNA.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.7

Section:  21.7

 

8) Enzymes that link the sugars and phosphates of the newly attached nucleotides to form a new strand during DNA replication.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.2

Section:  21.2

 

9) According to base-pairing rules, cytosine will pair only with this.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.1

Section:  21.1

 

Answers: 1) G 2) H 3) D 4) F 5) C 6) A 7) I 8) B 9) E

 

21.4  Short Answer and Essay Questions

 

1) Some tRNA often contains sections of noncomplementary, unusual bases (i.e., other than U, C, A, and G), which are added after transcription. What area of the tRNA would never contain such odd bases in a living organism?

Answer:  They would never be found in the anticodon because there would be no way to pair with any codon of the mRNA.

Bloom’s Taxonomy:  Synthesis/Evaluation

Learning Outcome:  21.3a

Global LO:  G2

Section:  21.3

 

2) Why is DNA replication semiconservative?

Answer:  DNA is replicated in a semiconservative process because this method has been hypothesized to be optimal for reducing replication errors in the copying process. This process involves opening the double-stranded DNA and using these strands as templates to produce new strands.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.2

Section:  21.2

 

3) Explain why some people fear genetically modified foods despite commercial organization claims that these foods are safe for human consumption.

Answer:  Some people feel that genetically modified foods haven’t been around long enough to allow for assessing the long-term effects of consumption. These foods may contain allergens that could lead to serious medical problems. The use of genetically modified foods could lead to herbicide resistance in other agricultural crops and weeds due to cross-pollination. Pollination of these plants could contaminate other plants and produce “super” weeds.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.7

Global LO:  G5

Section:  21.7

 

4) Compare and contrast DNA and RNA.

Answer:  DNA is double stranded; contains the sugar deoxyribose; possesses cytosine, guanine, adenine, and thymine; and is restricted to the nucleus. RNA is single stranded; contains a ribose sugar; possesses cytosine, guanine, adenine, and uracil (instead of thymine); and functions in protein synthesis in the cytoplasm. Both nucleic acids are composed of nucleotides and function in gene expression.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.3a

Section:  21.3

 

5) Genetically modified (GM) salmon have now been approved for sale in the United States. What environmental concern has been expressed about these salmon? What is being considered to reduce this risk?

Answer:  There is concern that the GM salmon may escape and outcompete the wild species. Scientists are planning to breed the fish separately and sterilize them prior to putting them in pens on the coast.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Global LO:  G5

Section:  21.6

 

6) The text says that bovine somatotropin can be given to cows to boost milk production. Suppose that it would be possible to alter the genes of cows so that the animals always made excess somatotropin. What concerns do you think people might have about this procedure?

Answer:  Some possible answers include the following: (1) The procedure might be too expensive for small dairy farmers, and the competition could drive them out of business. (2) There is uncertainty about the possible effect on people who drink the milk from such a cow. (3) There may be concerns that the genes might be accidentally transferred to animals in the surrounding areas, affecting them without our knowledge.

Bloom’s Taxonomy:  Synthesis/Evaluation

Learning Outcome:  21.6

Global LO:  G2|G5

Section:  21.6

 

7) Gene therapy is being explored as a means of permanently correcting a defective gene to cure a disease rather than to merely treat symptoms with drugs. Ideally, it would be best to correct these defective genes before a baby is even born. But if it’s possible to change diseased genes, what about changing genes that regulate other characteristics, such as height or eye color? Would it be desirable to change the genes of babies for more cosmetic purposes?

Answer:  The answer to this question is largely a matter of opinion. It’s clear to anyone that curing genetic disorders would be of great benefit. Changing genes for cosmetic reasons is less justifiable. Benefits and risks must be weighed.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.6

Global LO:  G5

Section:  21.6

 

8) Both DNA and RNA polymerases must be able to copy from a template strand with great accuracy. Still, either one can make mistakes that could lead to a mutation. For which one of these polymerases would a mistake be the most serious in the long term? Explain your answer.

Answer:  RNA polymerase makes mRNA, a molecule used in translation for a short period of time before it is broken down. DNA is the permanent record of a gene, so errors made by DNA polymerase are permanent.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.3b

Global LO:  G2

Section:  21.3

 

9) The drug Humulin is a modified form of the human insulin protein that is used to treat diabetes. Describe the process that would allow a drug company to take the gene responsible for producing this protein and, using bacteria, produce large amounts of this human protein.

Answer:  An insulin gene is isolated from a human pancreatic cell. This DNA is inserted into a bacterial plasmid, which is taken up by a bacterial cell. The cells are grown in volume, and the protein is collected.

Bloom’s Taxonomy:  Knowledge/Comprehension

Learning Outcome:  21.6

Global LO:  G5

Section:  21.6

 

10) Scientists study the genomes of many different living organisms besides humans, including, for example, fruit flies, yeasts, and mice. Of what value is understanding the genes of a mouse in comparison to those of a human? Are the two even remotely comparable?

Answer:  The basic metabolic machinery of all cells is essentially the same. Mice and humans have 90% of the same genetic makeup.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.7

Global LO:  G7

Section:  21.7

 

11) Could your lifestyle or the food you eat influence evolution? How?

Answer:  Such influence can occur through epigenetics, which involves a stable alteration in gene expression without changes in DNA sequence. DNA methylation and histone acetylation alter gene expression by affecting how tightly packaged the DNA molecule is. DNA methylation (adding a methyl group to the cytosine bases in DNA) turns off the activity of a gene by bringing in proteins that act to compact DNA into a tighter form. Histone acetylation, in contrast, makes the DNA less tightly coiled and gene expression easier. DNA methylation patterns can be affected by environmental factors, cause disease, be transmitted through generations, and potentially influence evolution.

Bloom’s Taxonomy:  Application/Analysis

Learning Outcome:  21.7

Global LO:  G7

Section:  21.7