Deck 1: Introduction to the Study of Cell and Molecular Biology

Question 1

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

Answer 1

B

Question 2

Who is generally credited with the discovery of cells?

A)Leeuwenhoek
B)Hooke
C)Schleiden
D)Schwann
E)Virchow

Answer 2

B

Question 3

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.

Answer 3

B

Question 4

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.

Question 5

Which of the following are considered to be eukaryotes?

A)amoebae
B)yeast
C)holly
D)starfish
E)All of these choices are correct.

Question 6

Which of the following are not considered to belong to the Archaea?

A)Methanogens
B)Halophiles
C)Acidophiles
D)Thermophiles
E)Eubacteria

Question 7

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

Question 8

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

Question 9

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
E)emzymes

Question 10

Who was the first person to describe living single cells?

A)Leeuwenhoek
B)Hooke
C)Schleiden
D)Schwann
E)Virchow

Question 11

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.

Question 12

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)nucleoid
D)pharmacopeia
E)genetome

Question 13

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.

Question 14

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.

Question 15

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

Question 16

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

Question 17

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.

Question 18

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

Question 19

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

Question 20

The process by which a relatively unspecialized cell becomes highly specialized is called _______.

A)differentiation
B)determination
C)degeneracy
D)denaturation
E)renaturation

Question 21

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.

Question 22

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

Question 23

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

Question 24

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

Question 25

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.

Question 26

Which of the following is not a model organism?

A)Mus musculus
B)Drosophila melanogaster
C)Homo sapiens
D)Arabidopsis thaliana
E)Caenorhabditis elegans

Question 27

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?

Question 28

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

Question 29

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

Question 30

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)megagene
E)exogenome

Question 31

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

Question 32

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

Question 33

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.

Question 34

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

Question 35

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

Question 36

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?

Question 37

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?

Question 38

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

Question 39

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

Question 40

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

Question 41

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?

Question 42

What is the name for undifferentiated cells that are both capable of self-renewal (production of more cells like themselves)and multipotent,that is capable of differentiating into two or more mature cell types?

Question 43

Briefly summarize the procedure involved in bone marrow transplantation.

Question 44

What is the normal purpose of hematopoietic stem cells in the bone marrow?

Question 45

Why are Archaea restricted to such harsh and difficult habitats?

Question 46

In bone marrow transplantation,what is the usual source of the donor cells? For what diseases is bone marrow transplantation most often used?

Question 47

Why are radiation and toxic chemicals ideal for destroying a recipient's blood cells?

Question 48

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?

Question 49

What are embryonic stem (ES)cells? How do ES cells differ from adult stem cells?

Question 50

How have investigators been able to improve the situation of golden retrievers suffering from an inherited disease very similar to the human skeletal-muscle disorder muscular dystrophy? What are isolated stem cells present in adult skeletal muscle called?

Question 51

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?

Question 52

Why is it hoped that transplantation of stem cells may help humans who have heart disease?

Question 53

What cells are likely to be the first used in human trials using ES cells for cell replacement therapy and what do these cells do? What have researchers had to do to get these cells to differentiate in culture? What happened when these human cells were transplanted into rats with paralyzing spinal cord injuries?

Question 54

Why are adult stem cells an ideal system for cell replacement therapies?

Question 55

Techniques for sequencing DNA have become very rapid and cost-efficient.Consequently,researchers have begun to sequence all of the genes of all of the microbes present in a given habitat.What term has been coined to describe such a collective genome? What information does such a collective genome provide? What is an example of a microbiome?

Question 56

What are glial cells?

Question 57

What factors presently limit the scope of organ transplantation as a treatment for human disease?

Question 58

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?

Question 59

You study two populations of mice,a lean population and an obese population.You measure the calories released from digested food by the microorganisms in the microbiomes isolated from the digestive tracts of the two mouse populations.One of the microbiomes releases significantly more calories than the other.Which microbiome would be likely to release significantly more calories? What significance might this have for human health?

Question 60

What is the difference between bone marrow transplantation and blood transfusion?

Question 61

How might ES cells be "customized" so that they possess the same genetic makeup as the individual who is being treated,thus protecting them from attack by the recipient's immune system? What is the major ethical question associated with this procedure? What practical impediments presently stand in the way of this procedure and how might they be removed?

Question 62

What is the primary risk of using human ES cells in cell replacement therapy to treat diseases like type I diabetes and macular degeneration? Why is this a risk?

Question 63

What is transdifferentiation?

Question 64

What advantage in cell replacement therapy do adult stem cells have over ES cells? What disadvantage do these same cells have relative to ES stem cells?

Question 65

What feature of iPS cells removes all the ethical reservations that accompany work with ES cells and makes it much easier to generate iPS cells in the lab? What difficulties must be overcome before iPS cells can be used as a source of cells for human therapy? How might the problem of immune rejection of iPS cell replacements eventually be avoided?

Question 66

It was long thought that cell differentiation was irreversible,i.e. ,once a cell like a fibroblast,a white blood cell or a cartilage cell has differentiated,it could not revert to any other cell type.Surprisingly,this is not the case.Shinya Yamanaka and his colleagues have succeeded in reprogramming a fully differentiated mouse cell,specifically a type of connective tissue fibroblast,into a pluripotent stem cell.How was this stunning feat accomplished? How did they demonstrate that iPS cells were indeed pluripotent?

Question 67

Which cells in the pancreas produce the enzymes responsible for digestion of food in the intestine? What do pancreatic beta cells do? What treatment was used to cause the reprogramming of pancreatic acinar cells into pancreatic beta cells? How did the researchers know that the transdifferentiation had,in fact,occurred and resulted in the production of more pancreatic beta cells? Why is the use of adenoviruses to deliver the genes in this experiment less of a risk in humans than using some other viruses would be?