Chapter 01 - A Preview of Cell Biology

Suggest one advantage that DNA sequencing has over nucleic acid hybridization. DNA sequencing can assess whether there is enough sequence complementarity to allow two strands to adhere to one another under specified conditions. DNA sequencing makes it possible to determine the tertiary and quaternary structure of a DNA strand. DNA sequencing makes it possible to determine the order of individual nucleotides along a DNA strand. 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.

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 that apply. Pizza with pepperoni and anchovies. Pizza with anchovies and onions. Pizza with pepperoni, anchovies, and onions. Pizza without pepperoni, anchovies, and onions. Pizza with pepperoni and onions.

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

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

electrophoresis.

Gregor Mendel was most influential in which field of biology? chromatography cytology biochemistry prokaryotic transformation genetics

genetics

To which of the following do Mendel's observations relate? thermodynamics diffusion heredity ideal gas laws gravity

heredity

Which type of microscope can detect density differences and thereby see organelles in living cells? phase contrast SEM TEM fluorescence

phase contrast

The scientific work that established DNA, rather than protein, as the molecule of heredity was performed prior to the elucidation of the double helix structure of DNA. Antonie van Leeuwenhoek's observation of internal cell structures. the description of the enzymatic steps of glycolysis. the formation of the chromosome theory of heredity. Mendel's work on heredity.

the elucidation of the double helix structure of DNA.

re 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 fluorescent microscope. phase-contrast microscope. transmission electron microscope. light microscope. digital video microscope.

transmission electron microscope.

Which of the following is true of a nanometer? A nanometer is equivalent to 10 Angstroms (Å). The nanometer is the most common measurement used in measuring whole cells. A nanometer is one millionth of a meter. A nanometer is about the size of a common bacterial cell. none of the above

A nanometer is equivalent to 10 Angstroms (Å)

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

All cells have a membrane-bound nucleus.

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

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

________ improved the original light microscope in the late 1600s, allowing the visualization of ________. Rudolf Virchow; collagen and muscle cells Robert Hooke; bacteria and viruses Robert Brown; cell structures using fluorescent antibodies Theodor Schwann; the internal structures of cells, such as ribosomes, nuclei, and Golgi bodies Antonie van Leeuwenhoek; sperm cells, bacteria, algae, and other protists

Antonie van Leeuwenhoek; sperm cells, bacteria, algae, and other protists

Now you should do the 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? Eat pizza in the morning instead of evening. Eat pizza of each kind (except pizza without ingredients) in at least three different days. Eat three pizzas at a time instead of one. Eat pizza without ingredients. Eat pizza of each kind (including pizza without ingredients) in at least three different days.

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

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

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

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

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

Which of the following is an application of immunofluorescence microscopy? Identifying which organelle or cellular compartment contains a particular protein. Identification of specific components of the immune system. Construction of three-dimensional images of structures smaller than 10 nm. Visualization of the surface structures of a specimen. Visualization of the natural fluorescence of a specimen under UV light.

Identifying which organelle or cellular compartment contains a particular protein.

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

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

Suggest one advantage that bioinformatics has over sequencing of a genome. 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. 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. Sequencing of a genome simply provides a large amount of data about the DNA present on a chromome, whereas bioinformatics provides a large amount of data about the DNA present in the entire genome. 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.

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.

How does brightfield microscopy allow images to be visualized? Specimens are illuminated with blue light to visualize internal features of cells smaller than 100 nm. Specimens are illuminated with white light. Specimens are fixed and have bright fluorescent molecules attached to them. Electrons strike the specimen being examined. Specimens are viewed under phased light to improve magnification.

Specimens are illuminated with white light.

Although the scientific method may sound rather foreign when described in formal terms, you probably use the scientific method frequently without even realizing it. Suppose, for example, that recently you often have heartburn. You realize that the heartburn is most likely to occur on nights after you have eaten your favorite pizza, with pepperoni, anchovies, and onions. You wonder if the heartburn is caused by eating pizza and, if so, which of the ingredients might be the culprit. Describe how you might begin an experimental process to determine whether the heartburn is due to the pizza. Eat other pizzas with different ingredients, but containing either pepperoni, or anchovies, or onions. Try to avoid eating pizza, but eat it's ingredients separately. Try to consume pizza on certain nights in different conditions. Try to keep track of your eating habits for a few weeks.

Try to consume pizza on certain nights in different conditions.

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

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

A scientific hypothesis is __________. a test in which only specific conditions are allowed to vary a testable explanation of a natural phenomenon the same as a theory a theory that has been confirmed

a testable explanation of a natural phenomenon

Which of the following is closest to a micrometer in size? the size of a ribosome the length of a plant cell the length of a chicken egg a typical prokaryotic cell the width of a strand of DNA

a typical prokaryotic cell

Cell biology emerged from which of the following fields of biology? biochemistry cytology and biochemistry biochemistry, cytology, and genetics genetics cytology

biochemistry, cytology, and genetics

Which type of microscopy enhances and amplifies slight changes in the phase of transmitted light? both differential interference contrast microscopy and phase-contrast microscopy digital video microscopy differential interference contrast microscopy fluorescence microscopy phase-contrast microscopy

both differential interference contrast microscopy and phase-contrast microscopy

Early microscopes did not allow clear visualization of cells because they were limited by refraction. magnification. resolution. number of kernels. both magnification and resolution.

both magnification and resolution.

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

centrifugation.

Which of the following types of light microscopy improves the resolution of thick specimens by illuminating one plane of the specimen at a time? confocal microscopy phase-contrast microscopy fluorescence microscopy brightfield microscopy differential interference contrast microscopy

confocal microscopy

Robert Hooke coined the term cell when studying thin slices of cork. These ________ were the first cells observed because ________. "little rooms"; they were 100 nm in diameter, much larger than most plant cells dead animal cells; they were immobile and did not need to be fixed before viewing compartments; they were actually the result of multiple cells that had merged and died to form large compartments that were easy to view dead plant cells; the thick cells walls did not require high resolution or magnification to view immune cells; they produce antibodies that embed in the cell membrane to make it visible

dead plant cells; the thick cells walls did not require high resolution or magnification to view

Which type of microscopy has the greatest resolving power? confocal scanning microscopy phase-contrast microscopy fluorescence microscopy digital video microscopy electron microscopy

electron microscopy

Which organelle stores most of the DNA in plant and animal cells? Golgi complex lysosome chloroplast nucleus mitochondrion

nucleus

Which of the following is smallest? ribosome protein prokaryote virus mitochondrion

protein