cell bio test #1; part one- chapters 1-2

Biochemical strand of cell biology

Centrifugation/ultracentrifugation and Chromatography/electrophoresis

Genetic strand of cell biology

Sequencing of a genome/bioinformatics and Nucleic acid hybridization/DNA sequencing

What was the limit of resolution of Leeuwenhoek's microscope? A. 0.83 μm B. 8.3 μm C. 83 μm D.830 μm

A. 0.83 μm

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

A. All cells arise only from preexisting cells.

Which of the following is an informational macromolecule? A. DNA B. ATP C. starch D. glycogen E. polypeptide

A. DNA

Suggest one advantage that electrophoresis has over chromatography. A. Electrophoresis separates molecules based on charge differences, thereby making it possible to separate molecules that are similar in size, shape, and density. B. Electrophoresis separates molecules based on differences in chemical properties, thereby making it possible to separate molecules that undergo similar chemical reactions. C. Electrophoresis separates molecules based on differences in solubility, thereby making it possible to separate molecules that are similar in mass and size. D. Electrophoresis separates molecules based on mass differences, thereby making it possible to separate molecules that are similar in molar mass.

A. Electrophoresis separates molecules based on charge differences, thereby making it possible to separate molecules that are similar in size, shape, and density.

Which type of microscope can detect density differences and thereby see organelles in living cells? A. Phase contrast B. TEM C. SEM D. Fluorescence

A. Phase contrast

Suggest one advantage that scanning electron microscopy has over transmission electron microscopy. A. Scanning electron microscopy makes it possible to visualize subcellular structures and macromolecules as if in three dimensions. B. Scanning electron microscopy makes it possible to only visualize cells and tissues as if in three dimensions. C. Scanning electron microscopy makes it possible to only visualize cells and tissues as if in two dimensions. D. Scanning electron microscopy makes it possible to visualize subcellular structures and macromolecules as if in two dimensions.

A. Scanning electron microscopy makes it possible to visualize subcellular structures and macromolecules as if in three dimensions.

Suggest one advantage that bioinformatics has over the sequencing of a genome. A. Sequencing of a genome simply provides a large amount of data about the DNA present in the genome, whereas bioinformatics uses computer analysis to aid in understanding and interpreting those data in terms of gene numbers and expression. B. Sequencing of a genome simply provides a large amount of data about the DNA present on a chromosome, whereas bioinformatics provides a large amount of data about the DNA present in the entire genome. C. Sequencing of a genome uses computer analysis to aid in understanding and interpreting those data in terms of gene numbers and expression, whereas bioinformatics simply provides a large amount of data about the DNA present in the genome. D. Sequencing of a genome simply provides a large amount of data about the DNA present in the genome, whereas bioinformatics techniques such as image and signal processing allow extraction of useful results from small amounts of raw data.

A. Sequencing of a genome simply provides a large amount of data about the DNA present in the genome, whereas bioinformatics uses computer analysis to aid in understanding and interpreting those data in terms of gene numbers and expression.

Define limit of resolution. A. The limit of resolution of a microscope is a measure of how close together two points can be and still be distinguished from one another when viewed through the microscope. B. The limit of resolution of a microscope is the clearance distance between the closest surface of the cover glass and the objective front lens. C. The limit of resolution of a microscope is the shortest distance between four separate points in a microscope's field of view that can still be distinguished as distinct entities. D. The limit of resolution of a microscope is the minimum distance or angular separation between two point objects which allows them to be resolved according to the Rayleigh criterion.

A. The limit of resolution of a microscope is a measure of how close together two points can be and still be distinguished from one another when viewed through the microscope.

Suggest one advantage that ultracentrifugation has over centrifugation. A. Ultracentrifugation is capable of much higher speeds and hence much greater centrifugal force than conventional centrifugation. B. Ultracentrifugation allows to separate mixtures containing charged molecules, whereas conventional centrifugation separates neutral biomolecules only. C. Ultracentrifugation allows the separation of biomolecules based on their size, shape, and/or density, whereas separation in conventional centrifugation is based on molecular mass only. D. Ultracentrifugation allows the separation of biomolecules with different physical properties, whereas conventional centrifugation precipitates all the biomolecules.

A. Ultracentrifugation is capable of much higher speeds and hence much greater centrifugal force than conventional centrifugation.

Which of the following is a unit of energy? A. calorie B. bond C. watt D. mole E. calorie and bond

A. calorie

Which of the following biochemical techniques uses an electrical field to separate macromolecules based on their mobility through a semisolid gel? A. electrophoresis. B. chromatography. C. light microscopy. D. ultracentrifugation. E. mass spectrometry.

A. electrophoresis.

Self-assembly of some structures may depend on A. information supplied by preexisting structures. B. the time associated with forming noncovalent interactions. C. the size of the monomers. D. the presence of lipids in the cytosol. E. all of the above.

A. information supplied by preexisting structures.

Which of the following is the smallest? A. protein B. virus C. mitochondrion D. prokaryote E. ribosome

A. protein

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

A. synthesizing urea in the laboratory from ammonium cyanate.

What would Leeuwenhoek have been able to see with his microscope?

Animal, plant and bacterial cells.

What are the approximate dimensions of the smallest structure that a contemporary cell biologist should be able to observe with a modern light microscope? A. 50-100 nm B. 200-350 nm C. 100-200 nm D. 400-500 nm

B. 200-350 nm

What was the limit of resolution of Hooke's microscope? A. 0.83 μm B. 8.3 μm C. 83 μm D. 830 μm

B. 8.3 μm

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

B. All cells have a membrane-bound nucleus.

Suggest one advantage that DNA sequencing has over nucleic acid hybridization. A. DNA sequencing makes it possible to identify species present in a sample of water, sewage, dirt, debris filtered from the air, or swab samples of organisms. B. DNA sequencing makes it possible to determine the order of individual nucleotides along a DNA strand. C. DNA sequencing makes it possible to determine the tertiary and quaternary structure of a DNA strand. D. DNA sequencing can assess whether there is enough sequence complementarity to allow two strands to adhere to one another under specified conditions.

B. DNA sequencing makes it possible to determine the order of individual nucleotides along a DNA strand.

What kind of pizza do you have to eat to know whether pepperoni is the reason of heartburn? (select two) A. Pizza with pepperoni and anchovies. B. Pizza with anchovies and onions. C. Pizza without pepperoni, anchovies, and onions. D. Pizza with pepperoni, anchovies, and onions. E. Pizza with pepperoni and onions.

B. Pizza with anchovies and onions. D. Pizza with pepperoni, anchovies, and onions.

Describe how you might begin an experimental process to determine whether the heartburn is due to pizza. A. Try to keep track of your eating habits for a few weeks. B. Try to consume pizza on certain nights in different conditions. C. Try to avoid eating pizza but eat its ingredients separately. D. Eat other pizzas with different ingredients but containing either pepperoni, or anchovies, or onions.

B. Try to consume pizza on certain nights in different conditions.

Which of the following is closest to a micrometer in size? A. the width of a strand of DNA B. a typical prokaryotic cell C. the length of a plant cell D. the length of a chicken egg E. the size of a ribosome

B. a typical prokaryotic cell

All of the following are common functional groups found in biological molecules except A. amino groups. B. butyl groups. C. carbonyl groups. D. sulfhydryl groups. E. phosphate groups.

B. butyl groups.

What could Leeuwenhoek see with his microscope but Hooke could not?

Bacterium, chloroplasts, and mitochondrion

In the lab, you choose to design a simple experiment to distinguish between hydrophilic and hydrophobic substances. You start by adding equal amounts of vinegar and oil to a container. After shaking, the vinegar and oil levels separate, based upon polarity and density. To this you add glucose and sodium citrate and shake again. Where do you expect to find the glucose and sodium citrate in greatest quantities? A. The glucose will concentrate in the vinegar, sodium citrate in the oil. B. Both will be uniform throughout both layers. C. Both will concentrate in the vinegar layer. D. Sodium citrate will concentrate in the vinegar, glucose in the oil. E. Both will concentrate in the oil layer.

C. Both will concentrate in the vinegar layer.

Which of the following is not a fundamental property of carbon? A. Carbon-containing molecules are stable. B. Carbon has a valence of 4. C. Carbon atoms are most likely to form ionic bonds with one another. D. Carbon-containing molecules are diverse. E. Carbon-containing molecules may form stereoisomers.

C. Carbon atoms are most likely to form ionic bonds with one another.

Now you should do similar experiments with other ingredients. On the basis of the data obtained you can make a conclusion about the impact of each component. What experiments should you do to prove your results? A. eat pizza in the morning instead of the evening. B. Eat pizza without ingredients. C. Eat pizza of each kind (including pizza without ingredients) on at least three different days. D. Eat pizza of each kind (except pizza without ingredients) on at least three different days. E. Eat three pizzas at a time instead of one.

C. Eat pizza of each kind (including pizza without ingredients) on at least three different days.

Suggest one advantage that electron microscopy has over light microscopy. A. Electron microscopy uses video cameras to collect digital images for computer storage. B. Electron microscopy uses complex mathematical algorithms to increase the contrast and resolution of digital images. C. Electron microscopy is capable of much greater resolution and hence much higher useful magnification. D. Electron microscopy is capable of a much greater limit of resolution and hence much less resolving power.

C. Electron microscopy is capable of much greater resolution and hence much higher useful magnification.

Which of the following statements about self-assembly is false? A. Self-assembly requires specific chemical conditions. B. Molecular chaperones are sometimes required for the proper folding and assembly of complex proteins. C. Self-assembly only occurs in structures composed of protein. D. The noncovalent interactions that drive supramolecular assembly processes are similar to those that dictate the folding of individual protein molecules. E. All of the above.

C. Self-assembly only occurs in structures composed of protein.

An enzyme synthesized in the laboratory is found to have little activity when compared to the enzyme extracted from cell culture. Both enzymes were examined and have identical amino acid compositions. What is the best explanation for the lack of activity of the synthesized enzyme? A. Denaturation of the synthesized enzyme was not complete. B. The van der Waals radius was altered during laboratory synthesis. C. The synthesized enzyme was not folded correctly because molecular chaperones were not present. D. The synthetic enzyme was not made of amino acids. E. The ATP required for self-assembly was present in the cell extract but not in the laboratory synthesis.

C. The synthesized enzyme was not folded correctly because molecular chaperones were not present.

Which of the following is INCONSISTENT with the cellular basis of life? A. The nuclear and mitochondrial DNA of a cell contains all of the information necessary for cellular reproduction. B. All anatomical structures and physiological processes of an organism are consequences of emergent properties of cellular structures and cellular processes. C. Viruses are living, acellular parasites. D. Cellular function is intimately linked to cellular structure.

C. Viruses are living, acellular parasites.

Which of the following molecules is most likely to cross the cell membrane directly by passive diffusion? A. fructose and insulin B. Na+ C. a steroid hormone (a hydrocarbon) D. insulin (a polypeptide) E. fructose (a sugar)

C. a steroid hormone (a hydrocarbon)

Radioisotopes have been important in the study of biochemical pathways because they __________. A. provide an important energy source for all organisms B. are major natural components of all cells C. allow scientists to trace the fate of specific molecules D. allow scientists to view individual molecules

C. allow scientists to trace the fate of specific molecules

Which of the following is not an activated monomer? A. uracil triphosphate B. adenosine triphosphate C. amino acid D. aminoacyl tRNA E. glucose-6-phosphate

C. amino acid

You wish to obtain a purified sample of mitochondria from lysed cells. The best way to obtain this sample would be A. agarose gel electrophoresis. B. both centrifugation and polyacrylamide gel electrophoresis. C. centrifugation. D. polyacrylamide gel electrophoresis. E. chromatography.

C. centrifugation.

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

C. transmission electron microscope.

Ribose has five carbon atoms, of which three are asymmetric. What is the maximum number of stereoisomers that may exist for ribose? A. 2 B. 4 C. 6 D. 8 E. 10

D. 8

Which of the following statements does NOT correctly validate the three strands that compose modern cell biology? A. Mutations in the cellular DNA can compromise cellular and macromolecular structure and function. B. Cellular structure arises from the combined structures of the macromolecules that compose cells. C. Cellular DNA contains information about the structure and function of cellular proteins. D. All of the other available answer choices validate the relationships between the three strands that compose modern cell biology.

D. All of the other available answer choices validate the relationships between the three strands that compose modern cell biology.

Why is a selectively permeable membrane so important to living things? A. Proteins will avoid a selectively permeable membrane. B. It allows cells to attach to adjacent tissues. C. The membrane may absorb several times its weight in cholesterol. D. It provides a good barrier between the inside and outside of the cell. E. all of the above

D. It provides a good barrier between the inside and outside of the cell.

How do large polar and charged molecules cross biological membranes? A. Large polar and charged molecules can't cross biological membranes. B. Large polar and charged molecules cross biological membranes via diffusion through the hydrophilic core of the membrane. C. Large polar and charged molecules must be hydrolyzed before they can cross a biological membrane. D. Large polar and charged molecules cross biological membranes via transport proteins that form hydrophilic channels through the membrane. E. Large polar and charged molecules can't cross biological membranes, because they must be hydrolyzed before they can.

D. Large polar and charged molecules cross biological membranes via transport proteins that form hydrophilic channels through the membrane.

Which of the following statements about the polymerization of macromolecules is false? A. Often the energy needed for polymerization is supplied by ATP. B. Macromolecules are synthesized by the stepwise addition of monomers. C. A monomer is usually activated by the coupling of the monomer to a carrier. D. Water is added to join the monomers of the macromolecules. E. The polymer chain usually has two different ends.

D. Water is added to join the monomers of the macromolecules.

The term amphipathic refers to those molecules that are A. hydrophilic. B. charged at both ends but with opposite charges. C. nonpolar at both ends. D. charged at one end and nonpolar at the other. E. hydrophobic.

D. charged at one end and nonpolar at the other.

Which type of microscopy has the greatest resolving power? A. fluorescence microscopy B. confocal scanning microscopy C. digital video microscopy D. electron microscopy E. phase-contrast microscopy

D. electron microscopy

The hierarchical nature of cellular structure is accurately illustrated in which of the following lists of substances (from smallest to largest)? A. nucleotides, chromosome, DNA, nucleus, cell B. protein, membrane, amino acids, chloroplast, cell C. cellulose, glucose, cell wall, cell D. nucleotides, DNA, chromosome, nucleus, cell E. nucleotides, nucleus, DNA, chromosome, cell

D. nucleotides, DNA, chromosome, nucleus, cell

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. amplicon D. transcriptome E. metabolome

D. transcriptome

Ionic bonds are important in biological structures. Which of the following pairs of molecules would form an ionic bond? A. a water molecule and a lipid B. two phospholipids C. two water molecules D. two amino acids with oppositely charged functional groups E. two different stereoisomers of the same sugar Submit

D. two amino acids with oppositely charged functional groups

Why do ionic substances such as NaCl dissolve so readily in water? A. NaCl is a very dry powder, and the water is able to soak into the salt. B. The sodium ions repel the negative end of the water molecule. C. Water molecules form spheres of hydration around the sodium and chloride ions. D. The charged ends of the water molecules are able to surround the oppositely charged salt ion. E. Water molecules form spheres of hydration around the sodium and chloride ions. Also, the charged ends of the water molecules are able to surround the oppositely charged salt ion.

E. Water molecules form spheres of hydration around the sodium and chloride ions. Also, the charged ends of the water molecules are able to surround the oppositely charged salt ion.

Which of the following is important in protein folding after the formation of a polypeptide? A. hydrogen bonding B. ionic bonding C. hydrophobic interactions D. van der Waals interactions E. hydrogen bonding, ionic bonding, van der Waals interactions, and hydrophobic interactions.

E. hydrogen bonding, ionic bonding, van der Waals interactions, and hydrophobic interactions.

Melvin Calvin and his colleagues used which of the following to deduce the steps in the Calvin cycle? A. negative staining B. ultracentrifugation C. electron microscopy D. Drosophila melanogaster E. radioisotopes

E. radioisotopes

Carbon can form ________ covalent bonds. A. single B. double C. triple D. single and double E. single, double, and triple

E. single, double, and triple

Cytological strand of cell biology

Light microscopy, electron microscopy, transmission electron microscopy and scanning electron microscopy

What could both Leeuwenhoek and Hooke see with their microscopes?

Liver cells

What would Hooke have been able to see with his microscope?

Plant and animal cells, but not bacterial cells.

What 3 things could neither Hooke, Leeuwenhoek nor a contemporary cell biologist see?

Ribosomes, DNA helix, and microfilament