Chapter 1: Cell Biology

1. Who was the first person to describe living single cells?
a) Leeuwenhoek
b) Hooke
c) Schleiden
d) Schwann
e) Virchow

Leeuwenhoek

2. The first compound light microscopes were constructed by the end of the sixteenth century.
What is a compound microscope?
a) It has a moveable stage.
b) It has two lenses.
c) Its lens is double the size of the original microscopes.
d) The lens has two different colors.
e) They have two different light sources.

It has two lenses.

3. Which of the following is a tenet of the Cell Theory?
4. All organisms are composed of one or more cells.
5. The cell is the structural unit of life.
6. Cells can arise only by division from a preexisting cell.
7. Cells divide only by fission.

\
a) 1

b) 2
c) 3
d) 4
e) 1, 2 and 3

1, 2 and 3

Who is generally credited with the discovery of cells?

Hooke

5. Despite being correct about the first two tenets of the Cell Theory, Schleiden and Schwann
made an error about another central feature of cells. What was their error?
a) They stated that all cells were smaller than 2 μ in diameter.
b) They claimed that all cells were exactly the same in every detail.
c) They stated that all cells were immortal.
d) They both agreed that cells could arise from noncellular materials.
e) They claimed that all cells had nuclei through their entire existence.

They both agreed that cells could arise from noncellular materials.

6. Which of the following characteristics is(are) not a basic property of cells?

a) Cells carry out a variety of emotional reactions.

b) Cells engage in numerous mechanical activities.
c) Cells generally respond to stimuli.
d) Cells are capable of self-regulation.
e) Cells evolve.

Cells carry out a variety of emotional reactions.

7. Which of the following characteristics is(are) a basic property of cells?
a) Cells are highly complex and organized.
b) Cells possess a genetic program and the means to use it.
c) Cells are capable of producing more of themselves.
d) Cells acquire and utilize energy.
e) All of these are correct.

All of these are correct.

8. The first culture of human cells was begun by George and Martha Gey of Johns Hopkins
University in 1951). The cells were obtained from a malignant tumor and named ______ cells
after the donor, _________.
a) HeLa, Herbert Lane
b) HeLa, Henrietta Lacks
c) Roberts, John Roberts
d) MaLe, Martin Lewis
e) HeLa, Helen Lassiter

HeLa, Henrietta Lacks

9. Cells grown in culture, outside the body are called ________ cells. They have become an
essential tool of cell and molecular biologists.
a) in vivo
b) live
c) in vitro
d) in culturo
e) vivacious

in vitro

10. A high powered microscope that allows investigators to examine the detailed surfaces of cells is called a ___________.

a) scanning electron microscope
b) transmission electron microscope
c) fluorescence microscope
d) scanning tunneling microscope
e) confocal laser scanning microscope

scanning electron microscope

11) A ______________ is used to reveal the detailed internal structure of cells.

a) scanning electron microscope
b) transmission electron microscope
c) fluorescence microscope
d) scanning tunneling microscope
e) confocal laser scanning microscope

transmission electron microscope

12. The apical ends of intestinal cells face the intestinal channel and have long processes that
facilitate the absorption of nutrients. What is the name of these processes and what cytoskeletal
element forms their internal skeleton?
a) microvilli, microtubules
b) villi, microtubules
c) microvilli, actin filaments
d) villi, actin filaments
e) microvilli, intermediate filaments

microvilli, actin filaments

13. Virtually all chemical changes that take place in cells require ________, molecules that
greatly increase the rate at which a chemical reaction occurs.

a) DNAs b) carbohydrates c) proteins d) enzymes

enzymes

14. You are conducting an experiment by trying to reproduce the work performed in 1891 by
Hans Driesch, a German embryologist. You are working with a fertilized sea urchin egg and
allow it to complete the first cell division after fertilization. You then carefully separate the two
cells of the embryo and allow their development to continue. Based on Driesch's experiment,
which result below would you expect to happen?

a) Both of the cells will die.
b) Both cells develop into complete and normal embryos that are somewhat smaller.
c) One cell develops into a normal, though smaller, embryo; the other dies.
d) One cell develops into half an embryo; the other develops into the other half of the embryo.
e) One cell develops into a defective embryo and the other dies.

Both cells develop into complete and normal embryos that are somewhat smaller.

15. What factor or factors discovered with electron microscopy distinguished prokaryotic from
eukaryotic cells?

* their size
* their color
* the types of their internal structures or organelles
* their fragility
a) 1
b) 2
c) 3
d) 4
e) 1 and 3

1 and 3

16. What characteristics distinguish prokaryotic and eukaryotic cells?
a) Eukaryotes have membrane-bound organelles; prokaryotes do not.
b) Prokaryotes have relatively little DNA; eukaryotes generally have much more.
c) Eukaryotic chromosomes are linear; prokaryotic chromosomes are circular.
d) Prokaryotic DNA is naked or nearly naked; eukaryotic DNA is usually heavily associated with
protein.
e) All of these are correct.

All of these are correct.

17. Which of the following are not considered to belong to the Archaea?
a) Methanogens
b) Halophiles
c) Acidophiles
d) Thermophiles
e) Eubacteria

Eubacteria

18. Which of the following are considered to be eukaryotes?
a) amoebae
b) yeast
c) holly
d) starfish
e) All of these choices are correct.

All of these choices are correct.

19. The genetic material of a prokaryotic cell is present in a _________, a poorly demarcated
region of the cell that lacks a boundary membrane to separate it from the surrounding cytoplasm.
a) nucleus
b) chromatic region

c) nucleiod

d) genetome

nucleiod

20. Bacteria will often pass a piece of DNA from a donor bacterial cell to a recipient bacterial
cell presumably through a structure called a pilus. What is this process called?
a) confirmation
b) transduction
c) transformation
d) conjugation
e) fission

conjugation

21. Cyanobacteria are obviously capable of photosynthesis, but many of them also convert
nitrogen gas into reduced forms of nitrogen (such as ammonia) that can be used by cells in the
synthesis of nitrogen-containing organic compounds, including amino acids and nucleotides.
This process is called ______.
a) nitrogen fixation
b) denitrification
c) nitrification
d) respiration
e) ammoniation

nitrogen fixation

22. The process by which a relatively unspecialized cell becomes highly specialized is called
_______.
a) differentiation
b) determination
c) degeneracy
d) denaturation
e) renaturation

differentiation

23. Bacteria often live in complex, multi-species communities, like the layer of plaque that
grows on your teeth; such a community is called a(n) _________.

a) biotome
b) microtome
c) biofilm
d) anatome
e) disneyfilm

c) biofilm

24. The rapidity and cost-efficiency of DNA sequencing has made it possible to sequence
virtually all of the genes present in the microbes of a given habitat. This generates a collective
genome for that habitat, which has come to be called a(n) _________.

a) metachron

b) metagenome

c) netagenome

d) meganene

e) exogenome

metagenome

25. The collection of bacteria that live on and within the human body are being isolated,
identified and characterized; they are referred to as the human ______. It has been demonstrated
that these organisms differ based upon the age, diet, geography and state of health of the human
from which they were obtained.
a) macrobiome
b) metagenome
c) minibiome
d) microbiome
e) homobiome

microbiome

26. Studies on mice suggest that bacterial species predominating in obese individuals differ from
those in the digestive tracts of lean individuals and that they play a role in weight gain in obese
individuals. What are these bacteria in obese individuals proposed to do that increases weight
gain in obese individuals?
a) They make obese mice eat more food.
b) They release chemicals that increase the caloric intake by the mice.
c) The bacteria in obese individuals may release more calories from digested food than their
counterparts in leaner individuals.
d) The bacteria in obese individuals turn the food in the intestines to fat.
e) The bacteria in obese individuals produce gas that makes their hosts obese.

The bacteria in obese individuals may release more calories from digested food than their counterparts in leaner individuals.

27. Which of the following is not a model organism?
a) Mus musculus
b) Drosophila melanogaster
c) Homo sapiens
d) Arabidopsis thaliana
e) Caenorhabditis elegans

Homo sapiens

28. The field of biological research in which biologists are attempting to create a living cell in
the laboratory, essentially from scratch is known as __________. More modestly, this branch of
biology also has a goal of developing novel life forms, beginning with existing organisms, that
have a unique value in medicine, industry or in cleaning up the environment.
a) megalomaniacal biology
b) synthetic biology
c) production-grade biology
d) industrial biology
e) pharmaceutical biology

synthetic biology

29. What is the most appropriate unit of measurement for macromolecular complexes including
ribosomes and microfilaments?

a) picometers

b) angstroms

c) nanometers

d) micrometers

e) centimeters

nanometers

30. What is the most appropriate unit of measurement for most types of cells?
a) picometers
b) angstroms
c) nanometers
d) micrometers
d) centimeters

micrometers

31. Why are viruses not considered to be organisms and not described as being alive?

* Virions are unable to reproduce by themselves.
* Virions are not able to metabolize by themselves.
* Virions are not able to synthesize DNA by themselves.
* Virions are not able to assemble spontaneously.
a) 1
b) 2
c) 3
d) 4
e) 1, 2 and 3

* 1, 2 and 3

32. Which of the following statements about viruses is not true?
a) All viruses are obligatory intracellular parasites.
b) All viruses are obligatory intercellular parasites.
c) Viruses occur in a wide variety of very different shapes, sizes and constructions.
d) A viral host may be a plant, an animal or a bacterial cell.
e) Viral genetic material can be either RNA or DNA.

All viruses are obligatory intercellular parasites.

33. Outside of a living cell, the virus exists as a particle called a(n) ________, which is little
more than a macromolecular package.
a) virulent
b) virusette
c) virulant
d) virion
e) infectoid

virion

34. Viruses like adenovirus, which causes respiratory infections in mammals, have a 20-sided
polyhedral capsid. What is this polyhedral shape called?
a) tetrahedron
b) dodechedron
c) polygon
d) icosahedron
e) octahedron

icosahedron

35. Among the most complex viruses are the ________, which are also the most abundant
biological entities on Earth.
a) mammalian viruses
b) bacterial viruses
c) vibriovirions
d) bacteriophages
e) bacterial viruses and bacteriophages

bacterial viruses and bacteriophages

36. Usually, a virus infects a cell and arrests the normal synthetic activities of the host, redirecting the cell to use its available materials to manufacture viral nucleic acids and proteins, which assemble into new viruses. Ultimately, the infected cell ruptures and releases a new generation of viral particles that can infect neighboring cells. This type of infection is called a(n) _________ infection. a) lytic b) proviral c) eluctable d) virulent e) avirulent

lytic

37. In some cases, an infecting virus does not lead to the death of the host cell, but instead
integrates its DNA into the DNA of the host cell's chromosomes. Integration of the viral DNA
can have different effects like exhibiting normal behavior until exposure to a stimulus that
activates the dormant viral DNA, production of viral progeny that bud off of the infected cell or a
loss of control over growth and division leading to malignancy. Such an infection is referred to
as a(n) ______ infection.
a) lytic
b) proviral
c) eluctable
d) virulent
e) avirulent

proviral

38. From what is the lipid-containing outer envelope surrounding the viral capsid of many
animal viruses derived?
a) the nuclear envelope
b) the outer mitochondrial membrane
c) the plasma membrane
d) the lysosomal membrane
e) the outer membrane of the chloroplast

the plasma membrane

39. Which of the following is not typically a behavior exhibited by a cell with a proviral
infection?


1. Immediate production of new viruses and subsequent lysis of the host cell.
2. Normal behavior until exposure to a stimulus, like UV radiation, that activates dormant viral
DNA, leading to lysis of the host cell and release of viral progeny.
3. Production of new viral progeny that bud at the cell surface without lysing the infected cell.
4. Loss of control in animal cells over their growth and division followed by malignancy.

a) 1
b) 2
c) 3
d) 4
e) 1 and 3

1

41. What advantageous uses have viruses been shown to have?
a) The activities of viral genes mimic those of host genes so they are useful for studying
mechanisms of DNA replication and gene expression in their much more complex hosts.
b) They can be used as a means to introduce foreign genes into human cells, which may serve as
a basis for treatment of human diseases by gene therapy.
c) Insect-killing viruses may play an increasing role in the war against insect pests.
d) Bacteria-killing viruses may play an increasing role in the war against bacterial pathogens.
e) All of these are correct.

All of these are correct.

42. Potato spindle-tuber disease, which causes potatoes to become gnarled and cracked, is
caused by an infectious agent consisting of a small circular RNA molecule that totally lacks a
protein coat. These infectious agents are thought to exert their effects by interfering with the
cell's normal path of gene expression. Such an infectious agent is known as a(n) __________.

a) provirous
b) bacteriophage

c) viroid
d) virunette
e) eviscerion

viroid

43. What major feature distinguishes the theoretical first eukaryotic common ancestor (FECA)
from prokaryotes?
a) DNA
b) closed internal compartments
c) plasma membrane
d) ribosomes
e) heterotrophy

closed internal compartments

44. You are observing a cell. Its cell wall is made of a long-chain polysaccharide called peptidoglycan. It has the ability to make all but the simplest molecules and can make all of the 20 amino acids. What kind of cell is it? If the cell contained pigments capable of photosynthesis, what would it be called?

The cell is a bacterium. With photosynthetic pigments, it is a Cyanobacterium.

45. A fertilized frog egg is allowed to divide and the two daughter cells are then separated. What
happens?

Both cells will develop into a complete tadpole. The tadpoles will, however, be smaller
than if the two daughter cells had not been separated.

46. Wilhelm Roux performed an experiment in which he allowed a frog embryo to divide into two cells. He then killed one of the cells with a hot needle, but did not separate the cell he had killed from the remaining cell. The embryo developed abnormally, leading Roux to conclude that the cells in a developing embryo have their developmental potential restricted at each division, even the first. Driesch and others demonstrated that separation of cells in a number of embryos resulted in the development of two smaller, but normal, embryos. Which of these investigators is most likely to have made a procedural error in his experimental design and what was it?

Roux made the mistake. By failing to remove the dead cell from the one he had
spared, he caused problems in the further development of the embryo. Had he removed the dead
cell, the remaining cell would probably have developed normally.

47. Why are viruses not considered by most biologists to be living organisms?

In order to reproduce, they must take over the cellular machinery of their host cell. They are incapable of reproducing on their own.

48. Prokaryotic cells are generally smaller than eukaryotic cells and have no membrane-bound
organelles, which act to transport some materials around the cell and compartmentalize certain
cellular processes. Why do prokaryotic cells not require such membrane-bound organelles?

Prokaryotic cells are smaller, and simple diffusion is sufficient to move things around
the cell.

49. Why are Archaea restricted to such harsh and difficult habitats?

These habitats closely resemble the Earth before oxygen appeared in the atmosphere, and they are relatively anaerobic. Archaea cannot survive in more aerobic environments.

50. If one accepts the suggestion that the Archaea are similar to the prokaryotes from which all
eukaryotes are descended, how does one explain the extreme environments in which they live
when their descendants thrive in more moderate environments?

The environments in which they live now more closely resemble the environment in which their ancestors evolved earlier in the Earth's history. Their descendant eukaryotes evolved to survive in the relatively benign environment now extant.

51. You are studying a virus. It has an icosahedral protein capsid and is surrounded by a lipid-
containing envelope. What kind of organism does the virus infect?

It is a eukaryotic virus. Prokaryotic viruses would not have a lipid envelope. Eukaryotic viruses often have lipid envelopes, which arise from the cell membrane that surrounds the mature virus as it buds from the cell.

52. A virus infects a cell that has been placed in culture. The cell grows into a clone of cells with
no apparent infection. Three months later, the cells are exposed to ultraviolet light. Shortly
thereafter, most of the cells lyse and shed large amounts of virus. What kind of infection is this?
What kind of infection results in a loss of growth control at some time after infection?

A provirus had been formed with the viral genome incorporated into the host cell's genome. The ultraviolet light caused the activation of the viral genome and subsequent lysis. A proviral infection.

53. You are studying an infectious agent, the effects of which resemble a virus. You isolate the
agent and treat it with an enzyme that degrades proteins and it is unaffected. However, if treated
with RNase, it loses its infectivity. What kind of pathogen is it most likely to be?

A viroid.

Embryonic stem cells have the potential for becoming an invaluable resource in: \n Option A: gene therapy. \n Option B: cell replacement therapy. \n Option C: hormone replacement therapy. \n Option D: none of the choices is correct.

cell replacement therapy

One of the goals of synthetic biology is to: \n A. create a living cell in the laboratory. \n B. develop novel life forms. \n C. "custom build" a particular species of an existing organism. \n D. All of these are goals of synthetic biology.

develop novel life forms

Which of these is NOT a common feature of eukaryotic and prokaryotic cells? \n Option A: Mechanisms for transcription and translation \n Option B: Genetic information encoded in DNA \n Option C: Construction of plasma membrane \n Option D: Cytoplasmic organelles such as endoplasmic reticulum and Golgi complex

Cytoplasmic organelles such as endoplasmic reticulum and Golgi complex

A virus is composed of each of the following EXCEPT: \n Option A: capsid. \n Option B: DNA or RNA. \n Option C: proteins. \n Option D: ribosomes.

Ribosomes

The smallest cells in the domain Bacteria are: \n Option A: archaea. \n Option B: cyanobacteria. \n Option C: viruses. \n Option D: mycoplasma.

mycoplasma

The hypothesis that explains the origin of eukaryotic cells as the result of two or more simpler cells developing a relationship with one another is called:

Option A: panspermia.

Option B: symbiosis.

Option C: evolution theory.

Option D: endosymbiont theory.

endosymbiont theory

Eukaryotic cells can be found in all of the following organisms EXCEPT: \n \n Option A: animals. \n Option B: bacteria. \n Option C: plants. \n Option D: fungi.

bacteria

Which of the following is NOT an example of a eukaryote? \n Option A: Bacterium \n Option B: Fungus \n Option C: Animal \n Option D: Plant

Bacterium

A distinctive feature of cells in multicellular organisms is their specialization as a result of __________.

Option A: differentiation

Option B: homeostasis

Option C: replacement

Option D: conversion

differentiation

Model organisms used by cell and molecular biologists include all of the following EXCEPT: \n \n Option A: mice. \n Option B: bacteria. \n Option C: nematodes. \n Option D: orangutans.

orangutans

Which of the following structures is the smallest? \n Option A: chloroplast \n Option B: lipid bilayer \n Option C: mitochondrion \n Option D: DNA molecule

DNA molecule

Animal cells have all of the following EXCEPT: \n \n Option A: a nuclear envelope. \n Option B: chloroplasts. \n Option C: Golgi apparatus. \n Option D: mitochondria.

chloroplasts

Model organisms are useful because: \n A \n Option A: they are particularly useful as research subjects. \n B \n Option B: they share many similarities with humans at the molecular level. \n C \n Option C: they share basic processes with most organisms. \n D \n Option D: all of the choices are correct.

all of the choices are correct

The flagellum is composed of a 9 + 2 arrangement of microtubules called the axoneme.

TRUE

The cell theory states that all present day cells have evolved from the same ancestor.

TRUE

The chloroplast is larger than the mitochondria

TRUE

Mitochondria and chloroplasts were prokaryotes that entered eukaryotic cells and became specialized to perform specific cellular functions.

TRUE

The Mitochondria shares a symbiotic relationship with animals, fungi, and plants therefore they would be unable to use oxygen to extract the maximum amount of energy from the food molecules that nourish them with out the mitochondria.

TRUE

Many prokaryotics are: \n Aerobic or Anearobic

Anearobic

Prokaryotes are the most diverse of cells

true

Larger cells are more likely to lose energy as heat to \n their surroundings

false

True or false: \n Larger cells have a greater surface area to volume ratio

false

Animals have no cell walls where as plants have cell walls.

true

What organelle and function pair can best explain their ability to divide? \n a Chloroplasts and peroxisomes because they both have their own DNA. \n b Mitochondria and chloroplasts due to their association with endosymbiosis theory. \n c Ribosomes and mitochondria as each is a result of regression theory. \n d Peroxisomes and lysosomes are both derived from engulfed bacteria.

Mitochondria and chloroplasts due to their association with endosymbiosis theory.

The Endosymbiosis theory best describes the origins of peroxisomes in eukaryotes.

False

All plant cells contain centrioles. \n \n true \n false

false

Fluorescence microscopy enables researchers to label and visualize a particular type of cellular protein or organelle.

true

The structure(s) that easily distinguishes a plant cell from an animal cell is/are \n chloroplasts. \n nucleus. \n cell wall. \n the Golgi apparatus.

chloroplasts and cell wall.

Due to the lack of an enzyme to break down lipids, excess accumulation of lipids in the brain leads to a human disease called Tay Sachs syndrome. The organelle most likely to lack the proper enzyme needed for lipid breakdown is \n lysosomes. \n tonoplasts. \n mitochondrion. \n Golgi apparatus. \n peroxisomes.

lysosomes

The organelle responsible for the biosynthesis of proteins that are destined for secretion by the cell is the \n Golgi apparatus. \n lysosome. \n vesicle. \n endoplasmic reticulum. \n mitochondria.

endoplasmic reticulum.

Chaperones keep proteins destined for the mitochondrial matrix in their three dimensional active structure. \n True \n False

False

The cell wall is a common feature to \n prokaryotic cells only. \n plant cells only. \n animal cells only. \n prokaryotic and plant cells. \n all cells.

prokaryotic and plant cells.

The nucleus is to eukaryotes as the ________ is to prokaryotes. \n plasmid \n RNA strand \n ribosome \n nucleoid \n nucleolus

nucleoid

When a friends falls to the floor after drinking too much alcohol the organelle that will best help them to detoxify will be \n a. lysosomes. \n b. smooth endoplasmic reticulum. \n c. mitochondrion. \n d. Golgi apparatus. \n e. peroxisomes.

smooth endoplasmic reticulum.

The cytoskeletal structure(s) that are composed of actin and regulate cell shape, cell movement and muscle contraction include \n microfilaments. \n intermediate filaments. \n microtubules. \n microtubules and intermediate filaments. \n microfilaments and microtubules.

microfilaments

In animal cells, microtubules grow from

* the plasma membrane.
* the outer membrane of the nuclear envelope.
* centrosomes containing centrioles.
* dimerization centers located throughout the cytosol.the tips of the chromosomes.

centrosomes containing centrioles.

To observe the three-dimensional structure of a cell the best type of microscopy would be

* fluorescence microscopy.
* standard light microscopy.
* scanning electron microscopy.
* differential-interference light microscopy.
* transmission electron microscopy.

.

scanning electron microscopy

The genome has more influence on the function of cells in different organs than does the proteome. \n True \n False

False

The best descriptions of the organelle peroxisomes include

* they were once viewed as being semi autonomous.
* they assist with detoxifying the cell.
* they have a double membrane around them.their structure includes their own DNA.
* they produce an enzyme that stops the accumulation of hydrogen peroxide and free radicals.

\

1,2,4

Large numbers of ribosomes are present in cells that produce \n steroids. \n lipids. \n glucose. \n starches. \n proteins.

proteins.

If organelles are able to divide and reproduce themselves like a cell those most likely to have this ability would be \n mitochondria only. \n chloroplasts only. \n peroxisomes only. \n both mitochondria and chloroplasts. \n mitochondria, chloroplasts, and lysosomes.

both mitochondria and chloroplasts.

The unique characteristics of ribosomes include

* composition of two subunits.
* an RNA composition.
* the cytosol site where all ribosomal components are produced.
* ribosomal proteins being produced in the cytosol.
* ribosomes being made of proteins, lipids and carbohydrates.

1,2,4

In order to visualize the fine structure of viruses and cytoskeletal filaments at 10-25 nanometers in diameter the type of microscopy that would be most effective is

* standard light microscopy.
* phase-contrast light microscopy.
* transmission electron microscopy.
* darkfield light microscopy.
* differential-interference microscopy

\

transmission electron microscopy.

Plasma membranes are a feature of \n all cells. \n prokaryotic cells only. \n eukaryotic cells only. \n plant cells only. \n animal cells only.

all cells.

Materials move in and out of the nucleus via endocytosis and exocytosis. \n True \n False

False

In eukaryotes, most proteins contain short stretches of amino acid sequences called sorting signals which direct the protein to the correct cellular location. \n True \n False

True

During a period of low water availability, the prokaryotic structure that would protect a cell from desiccation (drying out) is the \n pili. \n plasma membrane. \n nucleus. \n cell wall.

cell wall.

The gonads produce steroids. The specific steroid-producing organelle in gonad cells is \n

* ribosomes.
* lysosomes.
* smooth endoplasmic reticulum.
* mitochondria.contractile vacuole.

.

smooth endoplasmic reticulum.