Deck 1: A Preview of Cell Biology

Question 1

Which of the following is smallest?

A)ribosome
B)virus
C)protein
D)mitochondrion
E)prokaryote

Answer 1

C

Question 2

A scientist is examining motile protist.He wishes to determine their direction of movement.Which of the following microscopic techniques is least likely to be used to view these cells?

A)light microscopy
B)electron microscopy
C)differential interference contrast microscopy
D)fluorescence microscopy
E)phase-contrast microscopy

Answer 2

B

Question 3

Which of the following can only be viewed by electron microscopy?

A)frog eggs
B)DNA
C)nuclei
D)mitochondria
E)prokaryotes

Answer 3

B

Question 4

Which of the following statements is false ?

A)All organisms consist of one or more cells.
B)All cells arise from preexisting cells.
C)The cell is the basic unit of structure for all organisms.
D)All cells have a membrane-bound nucleus.
E)Cells come in a wide variety of sizes and shapes.

Question 5

Which type of microscopy has the greatest resolving power?

A)electron microscopy
B)phase-contrast microscopy
C)fluorescence microscopy
D)digital video microscopy
E)confocal scanning microscopy

Question 6

Robert Hooke coined the term cell when studying thin slices of cork.These ________ were the first cells observed because ________.

A)dead plant cells; the thick cells walls did not require high resolution or magnification to view
B)dead animal cells; they were immobile and did not need to be fixed before viewing
C)compartments; they were actually the result of multiple cells that had merged and died to form large compartments that were easy to view
D)immune cells; they produce antibodies that embed in the cell membrane to make it visible
E)"little rooms"; they were 100 nm in diameter,much larger than most plant cells

Question 7

Early microscopes did not allow clear visualization of cells because they were limited by

A)magnification.
B)number of kernels.
C)resolution.
D)refraction.
E)both magnification and resolution.

Question 8

Which of the following is an application of immunofluorescence microscopy?

A)Visualization of the natural fluorescence of a specimen under UV light.
B)Identification of specific components of the immune system.
C)Identifying which organelle or cellular compartment contains a particular protein.
D)Visualization of the surface structures of a specimen.
E)Construction of three-dimensional images of structures smaller than 10 nm.

Question 9

The limit of resolution can best be defined as

A)the distance that an object must be moved to be distinguished from its background.
B)the inverse of the wavelength of light; it is greatest for black light.
C)the distance that two objects must be apart to be distinguished as separate objects.
D)the solvent that must be available to remix a solution.
E)the magnification power of a microscope.

Question 10

Which organelle stores most of the DNA in plant and animal cells?

A)Golgi complex
B)mitochondrion
C)chloroplast
D)nucleus
E)lysosome

Question 11

Cell biology emerged from which of the following fields of biology?

A)biochemistry
B)cytology
C)genetics
D)biochemistry,cytology,and genetics
E)cytology and biochemistry

Question 12

Which type of microscopy enhances and amplifies slight changes in the phase of transmitted light?

A)differential interference contrast microscopy
B)digital video microscopy
C)fluorescence microscopy
D)phase-contrast microscopy
E)both differential interference contrast microscopy and phase-contrast microscopy

Question 13

Which of the following is closest to a micrometer in size?

A)the width of a strand of DNA
B)the length of a plant cell
C)the length of a chicken egg
D)a typical prokaryotic cell
E)the size of a ribosome

Question 14

The Latin phrase omnis cellula e cellula refers to a cellular principle.Which of the following statements is the best interpretation of this phrase?

A)Tissues are composed of similar cells.
B)Cells generally are found in clusters.
C)All cells arise only from preexisting cells.
D)Organs are composed of tissues and cells.
E)The cell is the basic unit of structure.

Question 15

________ improved the original light microscope in the late 1600s,allowing the visualization of ________.

A)Theodor Schwann; the internal structures of cells,such as ribosomes,nuclei,and golgi bodies
B)Robert Hooke; bacteria and viruses
C)Antonie van Leeuwenhoek; sperm cells,bacteria,algae,and other protists
D)Robert Brown; cell structures using fluorescent antibodies
E)Rudolf Virchow; collagen and muscle cells

Question 16

Scanning electron microscopy (SEM)is especially suited to

A)observing living specimens.
B)examining internal cellular structure.
C)creating a sense of depth.
D)both observing living specimens and creating a sense of depth.
E)simultaneously observing living specimens,examining internal cellular structure,and creating a sense of depth.

Question 17

Which of the following is true of a nanometer?

A)A nanometer is about the size of a common bacterial cell.
B)A nanometer is one millionth of a meter.
C)A nanometer is equivalent to 10 Angstroms (Å).
D)The nanometer is the most common measurement used in measuring whole cells.
E)None of the above.

Question 18

How does brightfield microscopy allow images to be visualized?

A)Specimens are illuminated with white light.
B)Electrons strike the specimen being examined.
C)Specimens are fixed and have bright fluorescent molecules attached to them.
D)Specimens are illuminated with blue light to visualize internal features of cells smaller than 100 nm.
E)Specimens are viewed under phased light to improve magnification.

Question 19

You are working on a project that involves the direct observation of DNA molecules.The microscope that would give you the best information at this time would be the

A)light microscope.
B)phase-contrast microscope.
C)transmission electron microscope.
D)digital video microscope.
E)fluorescent microscope.

Question 20

Which of the following types of light microscopy improves the resolution of thick specimens by illuminating one plane of the specimen at a time?

A)fluorescence microscopy
B)phase-contrast microscopy
C)confocal microscopy
D)differential interference contrast microscopy
E)brightfield microscopy

Question 21

1 mm = ________ nm

A)1,000,000
B)1000
C)10
D)1/1000
E)1/1,000,000

Question 22

The scientific work that established DNA,rather than protein,as the molecule of heredity was performed prior to

A)Mendel's work on heredity.
B)the elucidation of the double helix structure of DNA.
C)Antonie van Leeuwenhoek's observation of internal cell structures.
D)the description of the enzymatic steps of glycolysis.
E)the formation of the chromosome theory of heredity.

Question 23

The classic work of Friedrich Wöhler (1828)that united the fields of biology and chemistry was based on the

A)discovery of yeast ferments.
B)production of urea in the laboratory.
C)discovery of ATP.
D)identification of nucleotide bases.
E)analysis of gene segregation.

Question 24

Gregor Mendel was most influential in which field of biology?

A)genetics
B)chromatography
C)biochemistry
D)prokaryotic transformation
E)cytology

Question 25

You are studying the response of macrophages infected with the intracellular bacterium Brucella ,specifically by examining which gene products are being expressed.You would be studying the macrophage ________ to obtain this information.

A)proteome
B)genome
C)transciptome
D)amplicon
E)metabolome

Question 26

Which of the following is mismatched?

A) Escherichia coli - genetics
B) Drosophila melanogaster - embryogenesis
C) Mus musculus - immunology
D) Caenorhabditis elegans - photosynthesis
E) Arabidopsis thaliana - plant gene function

Question 27

Wöhler revolutionized biology through his demonstration that biological molecules are governed by the ordinary laws of physics and chemistry.He demonstrated this principle by

A)synthesizing urea in the laboratory from ammonium cyanate.
B)developing techniques for isolating,purifying,and analyzing subcomponents of cells.
C)defining the laws of heredity.
D)discovering active agents in cell extracts that were specific biological catalysts that have since come to be called enzymes.
E)inventing mass spectrometry which is commonly used to determine the size and composition of individual proteins.

Question 28

Scientists use various terms to describe conclusions reached through the scientific method.Which of the following terms conveys the least degree of certainty?

A)theory
B)hypothesis
C)law
D)both hypothesis and theory
E)both theory and law

Question 29

To which of the following do Mendel's observations relate?

A)thermodynamics
B)gravity
C)ideal gas laws
D)heredity
E)diffusion

Question 30

Jacques Monod and François Jacob deduced the mechanism responsible for the regulation of prokaryotic gene expression.They are,therefore,responsible for launching the era of

A)the scientific method.
B)molecular genetics.
C)biochemistry.
D)light microscopy.
E)radioisotopes.

Question 31

Melvin Calvin and his colleagues used which of the following to deduce the steps in the Calvin cycle?

A)negative staining
B)Drosophila melanogaster
C)electron microscopy
D)ultracentrifugation
E)radioisotopes

Question 32

You wish to obtain a purified sample of mitochondria from lysed cells.The best way to obtain this sample would be

A)centrifugation.
B)chromatography.
C)polyacrylamide gel electrophoresis.
D)agarose gel electrophoresis.
E)both centrifugation and polyacrylamide gel electrophoresis.

Question 33

Which of the following biochemical techniques uses an electrical field to separate macromolecules based on their mobility through a semisolid gel?

A)light microscopy.
B)ultracentrifugation.
C)chromatography.
D)electrophoresis.
E)mass spectrometry.

Question 34

The steps of the scientific method,in the correct order,are

A)design experiments,draw conclusions,collect data,interpret results,make observations,and test the hypothesis.
B)make observations,formulate the hypothesis,design experiments,collect data,interpret results,and draw conclusions.
C)collect data,interpret results,test the hypothesis,design experiments,make observations,and draw conclusions.
D)collect data,interpret results,test the hypothesis,make observations,and design experiments.
E)none of the above.

Question 35

All of the following are model organisms,except

A)Saccharomyces cerevisiae.
B)Drosophila melanogaster.
C)Caenorhabditis elegans.
D)Arabidopsis thialana.
E)Homo sapiens.

Question 36

In studying osteoporosis in humans,you wish to test a newly designed treatment for efficacy.Your best choice for a model organism would be

A) Escherichia coli.
B) Mus musculus.
C) Caenorhabditis elegans.
D) Arabidopsis thaliana.
E) Pisum sativum.

Question 37

A microtome is used to

A)view microscopic organisms.
B)slice thin sections of specimens.
C)focus short wavelengths of light.
D)manipulate tiny objects.
E)dissect cellular organelles.

Question 38

Once a scientific theory becomes a law,it

A)cannot be changed.
B)cannot be challenged.
C)becomes static.
D)is subject to modification.
E)is irrefutable.

Question 39

The outcome of the joining of cytology and biochemistry yielded a better understanding of the cell by

A)identification of cellular structures.
B)identification of cellular biochemical pathways.
C)creating bioinformatics.
D)identification of cellular structures and biochemical pathways.
E)identification of biochemical pathways and creating bioinformatics.

Question 40

Which of the following is an important characteristic for a model organism?

A)marginally characterized
B)difficult to manipulate in the laboratory
C)prone to random changes that alter primary characteristics
D)widely studied
E)all of the above

Question 41

A number of different types of microscopy exist.Each type of microscopy has advantages and disadvantages.Can you identify the microscope that would be most advantageous for the situations below?
a.A cell biologist wishes to visualize the ribosomes of a cell.
b.A microbiologist wishes to examine the motility of a bacterium.
c.An immunologist wishes to determine if a lymphocyte possesses a certain surface protein.
d.A virologist is trying to determine the three-dimensional shape of a virus.
e.A pathologist is trying to examine the cytoplasm of a cell for changes that result from viral infection.

Question 42

The ________ was developed in the late 1920s by Theodore Svedberg.He originally used it to determine the sedimentation rate of proteins.

Question 43

Melvin Calvin used ________,a specific ________,to deduce the Calvin cycle of photosynthesis.

Question 44

The following paragraph describes the activities of hypothetical scientists.After reading this paragraph,list the steps of the scientific method,and list the activities that correspond to the steps of the scientific method.
A rancher noticed that several grazing animals had become sick after grazing in a new area.The rancher asked a team of scientists to analyze this problem.They visited the area and found that the food available to the animals was similar to the food they had been eating.The water supply in the area was adequate but limited to a single spring.Some of the scientists felt that the water might be contaminated with a pathogen.Therefore,they collected water samples from the spring in the new area and compared them with water samples taken from previous grazing sites.The scientists noticed that water from the new area was cloudier than water obtained from other areas.Culturing this water revealed that a pathogenic strain of bacteria was present.This bacterial strain was found to be identical to a strain obtained from sick animals.This strain was not present in healthy animals.They concluded that a contaminated water supply in the new area was responsible for the problem and instructed the rancher to avoid the water supply.The disease was not found in the rancher's livestock again.

Question 45

You have identified a new molecule associated with the immune system that drastically reduces cell division by tumor cells in vivo.Develop a hypothesis and design an experiment to test your hypothesis using a model organism.Include an explanation as to why it is the best model for your experiment.

Question 46

Glycolysis is also called the ________ pathway after the scientists who did most of the work to define it.

Question 47

You have been given a sample of Mimivirus,which has the largest capsid diameter of all currently known viruses (600 nm)and has the form of a 20-sided polyhedron (an icosahedron).Based on your knowledge of microscopes,what would you be able to see/determine about mimiviral structure using each of the following microscopes?
a.simple compound (light)microscope
b.fluorescent microscope using fluorescently labeled antibodies to a novel capsid protein
c.scanning electron microscope

Question 48

In 1880,Walther Flemming identified ________,threadlike bodies seen in dividing cells.

Question 49

________ is a biochemical technique that allows one to separate biological molecules based on size,shape,and/or affinity for specific molecules or functional groups.

Question 50

________ synthesized urea in the laboratory from inorganic starting materials.Much of what is now called ________ dates from this discovery.

Question 51

The total protein content of the cell is called the ________.

Question 52

Around 1914,________ determined that DNA was an important component in ________ by using a staining technique that is still in use today.

Question 53

A(n)________ is an instrument used to separate subcellular structures and macromolecules on the basis of size,shape,and density.________ developed this instrument in Sweden during the period 1925-1930.

Question 54

Because of the low penetration power of electrons,samples for transmission electron microscopy must be extremely thin.A(n)________ is able to cut sections as thin as 20 nm.

Question 55

To be useful to scientists,a hypothesis must be ________; in other words,the hypothesis must be able to be confirmed or discredited.

Question 56

A scientific ________ must be so thoroughly confirmed that virtually no doubt remains about its accuracy.