Chapter 6 Biology 1
Which structure is not part of the endomembrane system? chloroplast nuclear envelope plasma membrane ER Golgi apparatus
chloroplast
Thylakoids, DNA, and ribosomes are all components found in _____. chloroplasts nuclei . mitochondria lysosomes
chloroplasts
The _____ is composed of DNA and protein. mitochondrion centriole ribosome flagellum chromatin
chromatin Chromatin is composed of DNA and protein.
The primary role of _____ is to bind animal cells together. gap (communicating) junctions desmosomes tight junctions plasmodesmata the cytoskeleton
desmosomes The primary role of desmosomes (anchoring junctions) is to bind cells together.
Which of the following is the simplest collection of matter that can live? Cell Tissue Organ Molecules None of the listed responses is correct.
Cell By definition, a cell is the smallest and simplest unit of life, one that can conduct its daily work and reproduce itself.
Microtubules and microfilaments commonly work with which of the following to perform many of their functions? Ribosomes Lysosomes RNA Golgi apparatus None of the listed responses is correct.
Golgi apparatus Microtubules guide vesicles from the ER to the Golgi and from the Golgi to the plasma membrane.
Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell, they __________. have no membrane-bounded organelles in their cytoplasm lack chromosomes have no ribosomes lack a plasma membrane have a smaller nucleus
have no membrane-bounded organelles in their cytoplasm Prokaryotic cells have no membrane-bounded organelles.
The diameter of a typical eukaryotic cell is approximately ten times the diameter of a typical prokaryote. What is the ratio of the volume of typical eukaryotic: prokaryotic cells? 100:1 1000:1 10:1
1000:1 As the diameter of a cell increases, other dimensions also change. For two cells of approximately equivalent shape but different diameters, surface area increases as the square of diameter, and volume increases as the cube of diameter. Thus, if a eukaryotic cell is ten times the diameter of a prokaryote, its surface area will be one hundred (102) times that of the prokaryote and its volume will be one thousand (103) times that of the prokaryote.
Which of these structures stores, modifies, and packages products? E C B D A
A The Golgi apparatus modifies, stores, and packages products of the ER.
Which of the following is/are likely to limit the maximum size of a cell? The shape of the cell The time it takes a molecule to diffuse across a cell The cell's surface-to-volume ratio All of the choices are correct. None of the choices is correct.
All of the choices are correct.
_____ is/are identical in structure to centrioles. Nuclear envelopes Chromatin Microfilaments Mitochondria Basal bodies
Basal bodies Basal bodies and centrioles have identical structures.
Which of the following statements correctly describes a common characteristic of a plant cell wall and an animal cell extracellular matrix? Both are permeable to water and small solutes. Both contain large amounts of collagen. Both are composed primarily of carbohydrates. Both are permeable to water and small solutes, and both contain large amounts of collagen. Both are permeable to water and small solutes, both contain large amounts of collagen, and both are composed primarily of carbohydrates.
Both are permeable to water and small solutes. Both plant cell walls and the ECM of animal cells allow movement of water and small solutes.
Which of the following are common traits of chloroplasts and mitochondria? Both have their own DNA. Both are surrounded by a single membrane. Both are found in plant and animal cells. Both reproduce by meiosis. Proteins for both are synthesized on ribosomes in the rough ER.
Both have their own DNA. Mitochondria and chloroplasts contain their own DNA and ribosomes.
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter _____. A B C D E
C The plasma membrane is selectively permeable.
Choose the letter that indicates the organelle that contains most of a cell's DNA. E C B D A
C The nucleus contains most of a cell's DNA.
Which of the following statements is true about cell fractionation? Cell fractionation separates cells into their component parts. Cell fractionation uses strong acids to break apart cells. Cell fractionation is no longer used in modern cell biology. Cell fractionation requires the use of a scanning electron microscope. None of the listed responses is correct.
Cell fractionation separates cells into their component parts. The organelles are usually separated by centrifugation.
Which of the following structures is found in animal cells but not in plant cells? Golgi apparatus Rough endoplasmic reticulum Mitochondria Plasma membrane Centrioles
Centrioles Although plant cells have a microtubule organizing center, they lack a pair of centrioles.
Which of the following statements about chloroplasts and mitochondria is true? Chloroplasts and mitochondria are components of the endomembrane system. Chloroplasts and mitochondria synthesize some of their own proteins. Chloroplasts, but not mitochondria, are completely independent of the cell of which they are a part. Chloroplasts and mitochondria have three sets of membranes. Mitochondria, but not chloroplasts, contain a small amount of DNA.
Chloroplasts and mitochondria synthesize some of their own proteins. Chloroplasts and mitochondria can synthesize some of their own proteins because they contain DNA and ribosomes.
Which of the following is false in respect to eukaryotic chromosomes? Chromosomes are present even when cells are not actively synthesizing proteins. Chromosomes appear in an obvious form only as a cell is about to divide. Chromosomes are present throughout a cell's reproductive cycle. All eukaryotic cells possess one or more chromosomes. None of the listed responses is false.
Chromosomes appear in an obvious form only as a cell is about to divide. This is false. Although chromosomes become more compact as a cell prepares to divide, they are always present in the cell.
Basal bodies are most closely associated with which of the following cell components? Cilia The central vacuole Golgi apparatus Mitochondria Nucleus
Cilia The microtubule assembly of a cilium or flagellum is anchored in the cell by a basal body.
Which statement about the cytoskeleton is true? Microfilaments are more permanent structures in cells compared to intermediate filaments and microtubules. Plant cells lack a cytoskeleton because they have a rigid cell wall. Microtubules are chains of proteins that resist stretching. Intermediate filaments are hollow tubes of protein that provide structural support. Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.
Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm. The interaction of motor proteins with the cytoskeleton is responsible for the movement of organelles in cells.
Which of these provides the cell with structural support? D B C E A
D Microfilaments are a component of the cytoskeleton.
The DNA-containing region of this bacterial cell is indicated by the letter _____. A B C D E
D The nucleoid region contains DNA.
A cell has formed a food vacuole as it ingested a food particle. Which of the following events is associated with the breakdown of that food particle? Proteins for digestion of the food particle were initially processed in mitochondria. Enzymes for the breakdown of the food are delivered to the food vacuole from the cytosol. Proteins for digestion of the food are made by ribosomes in the Golgi apparatus. The membrane of the food vacuole is derived from the cell wall. Digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm.
Digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm. Digestion occurs within a vesicle. If the digestive enzymes were in the cytosol, they might degrade essential components of the cell.
Which of these is the double membrane that encloses the nucleus? A C B D E
E This is the nuclear envelope.
Consider a protein that is made in the rough endoplasmic reticulum. You observe that when the synthesis of the protein is completed, the protein is located in the ER membrane. Where else in the cell might this protein be found? In the internal space of the Golgi apparatus, being modified before the protein is excreted In a mitochondrion, functioning in ATP synthesis Embedded in the plasma membrane, functioning in the transport of molecules into the cell In the cytoplasm, functioning as an enzyme in carbohydrate synthesis In the aqueous interior of a lysosome, functioning as a digestive enzyme
Embedded in the plasma membrane, functioning in the transport of molecules into the cell This is the only answer in which the protein is a membrane protein.
In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells? Eukaryotic cells are much more successful than prokaryotic cells. Eukaryotic cells can synthesize proteins, but prokaryotic cells cannot. Eukaryotic cells are compartmentalized, which allows for specialization. Eukaryotic cells lack many of the organelles found in prokaryotes. Eukaryotic cells are larger than prokaryotic cells.
Eukaryotic cells are compartmentalized, which allows for specialization. The presence of membrane-bounded organelles in eukaryotes permits cellular functions to occur in specialized, isolated compartments.
Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. Photographic emulsions are prepared at different times during the chase. Where would the black spots appear on an emulsion prepared 3 hours after the pulse? Rough ER Exterior of the cell Golgi apparatus Secretory vesicles
Exterior of the cell Black spots would appear on the exterior of the cell after 3 hours, indicating that the proteins had been secreted from the cell.
True or false? Proteins produced during the "chase" phase of a pulse-chase experiment are labeled with radioactive material.
False During the chase phase, cells are provided with a large amount of nonradioactive material, so they are not labeled.
_____ are surface appendages that allow a bacterium to stick to a surface. Cell walls Fimbriae Mitochondria Flagella Ribosomes
Fimbriae Fimbriae enable bacterial cells to stick to a surface.
_____ aid in the coordination of the activities of adjacent animal cells. Gap (communicating) junctions Desmosomes Plasmodesmata Keratin fibers Tight junctions
Gap (communicating) junctions Gap junctions allow for the passage of material between cells, thus facilitating communication between these cells.
A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually found in a cell's plasma membrane. The protein in the plasma membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the __________. rough endoplasmic reticulum plasma membrane transport vesicles Golgi apparatus smooth endoplasmic reticulum
Golgi apparatus Vesicles carrying proteins from the rough ER fuse with the Golgi apparatus, where the proteins may be altered.
Which of the following sequences represents the order in which a protein made in the rough endoplasmic reticulum might move through the endomembrane system? Golgi apparatus → lysosome Nuclear envelope → lysosome Golgi apparatus → mitochondria Plasma membrane → nuclear envelope Lysosome → plasma membrane
Golgi apparatus → lysosome Proteins of the endomembrane system are synthesized in the rough ER, modified and sorted in the Golgi, and then transported to other organelles of the endomembrane system such as vacuoles.
What is the first step in a pulse-chase experiment? Examining cells for the location of the labeled molecules Incubating cells with an unlabeled molecule Incubating cells with a labeled molecule Preparing cells for electron microscopy
Incubating cells with a labeled molecule Cells are first "pulsed" with a large amount of labeled material for a short time.
A researcher wants to film the movement of chromosomes during cell division. Which type of microscope should she choose, and why is it the best choice? Light microscope because the specimen is alive Scanning electron microscope because of its ability to visualize the surface of subcellular objects Transmission electron microscope because of its high resolving power Light microscope because of its high resolving power Transmission electron microscope because of its high magnifying power
Light microscope because the specimen is alive Although the resolution of the light microscope is far less than that of electron microscopes, light microscopy is the only technique that permits one to observe living cells.
Which of the following categories best describes the function of the rough endoplasmic reticulum? Structural support of cells Manufacturing Breakdown of complex foods Information storage Energy processing
Manufacturing The rough endoplasmic reticulum is involved in the manufacture of proteins for the endomembrane system
Which of the following structures is found in eukaryotic but not prokaryotic cells? Cytosol DNA Ribosomes Plasma membrane Mitochondria
Mitochondria Only eukaryotic cells have membrane-bound organelles such as mitochondria.
Which of the following is false? Mitochondria contain ribosomes in the intermembrane space. The folds of the inner mitochondrial membrane are called cristae. Mitochondria are involved in energy metabolism. Mitochondria have more than one membrane. Mitochondria possess their own DNA.
Mitochondria contain ribosomes in the intermembrane space. The ribosomes in the mitochondria are found in the matrix of the mitochondria, not in the intermembrane space.
Which of the following five membranes is most likely to have a lipid composition that is distinct from those of the other four? Lysosome membrane Mitochondrial outer membrane Golgi apparatus Endoplasmic reticulum Plasma membrane
Mitochondrial outer membrane The mitochondria are not part of the endomembrane system and must synthesize their own lipids.
Cilia and flagella move due to the interaction of the cytoskeleton with which of the following? Tubulin Mitochondria Pseudopodia Motor proteins Actin
Motor proteins Motor proteins, such as dynein, use energy to move parts of the cytoskeleton.
Which of the following functions is NOT associated with the cytoskeleton in eukaryotic cells? maintaining the position of the nucleus in the cell the contraction of muscle cells in animals .determining the shape of animal cells the beating of cilia or flagella Movement of RNA molecules from the nucleus to the cytoplasm
Movement of RNA molecules from the nucleus to the cytoplasm RNA molecules exit the nucleus via nuclear pores.
What scientific hypotheses can be tested by a pulse-chase experiment? Movement of molecules through a cell over time The steady-state amount of protein in a cell The amino acid sequence of a protein Solubility of a molecule
Movement of molecules through a cell over time Pulse-chase experiments allow for the tracking of molecules in a cell over time.
Which type of cell is most likely to have the largest number of mitochondria? Muscle cells in the legs of a marathon runner Inactive yeast cells that are stored for future use Photosynthetic cells in the leaves of a tree Bacterial cells that are growing on sugars Nondividing cells in the skin on your finger
Muscle cells in the legs of a marathon runner Cellular respiration releases energy that cells need in order to carry out their functions. Active muscle cells need large amounts of energy.
Select the correct statement describing cellular structure or function. Plant and animal cells both carry out cellular respiration, producing ATP. Only plant cells contain chloroplasts, and only animal cells contain mitochondria. Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell.
Plant and animal cells both carry out cellular respiration, producing ATP. All plant and animal cells carry out cellular respiration in mitochondria, producing ATP.
Which one of the following statements about the endomembrane system is correct? Most of the phospholipids of the endomembrane system are synthesized in the mitochondria. The endoplasmic reticulum is continuous with the plasma membrane. Mitochondria function in the modification and sorting of lipids and proteins. Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system. Ribosomes move lipids and proteins among the different organelles of the endomembrane system.
Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system. Proteins that will be secreted are always enclosed by some membrane of the endomembrane system until they are secreted.
Which of the following groups is primarily involved in synthesizing molecules needed by the cell? Rough endoplasmic reticulum, lysosome, vacuole Vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum Lysosome, vacuole, ribosome Ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum Smooth endoplasmic reticulum, ribosome, vacuole
Ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum Each of these structures is capable of synthesizing molecules needed by cells.
Which of the following organelles might be found inside other organelles? Transport vesicles Ribosomes The nucleolus Mitochondria No organelles are found inside other organelles.
Ribosomes Ribosomes are nonmembranous organelles that are found in the cytoplasm but also in mitochondria and chloroplasts.
_____ are the sites of protein synthesis. Golgi apparatuses Mitochondria Peroxisomes Ribosomes Microfilaments
Ribosomes Ribosomes are the site of protein synthesis.
Which of the following features do prokaryotes and eukaryotes have in common? Ribosomes, nucleus, and plasma membrane Mitochondria, cytoplasm, and plasma membrane Mitochondria, ribosomes, and cytoplasm Ribosomes, plasma membrane, and cytoplasm Nucleus, plasma membrane, and ribosomes
Ribosomes, plasma membrane, and cytoplasm All of these parts are found in all living cells, since those cells all need to make proteins (ribosomes), separate from the environment (plasma membrane), and conduct metabolism (cytoplasm).
What path does a protein in the secretory pathway take, starting from its site of synthesis? Rough ER, Golgi apparatus, secretory vesicles, plasma membrane Golgi apparatus, rough ER, secretory vesicles, plasma membrane Plasma membrane, secretory vesicles, Golgi apparatus, rough ER Rough ER, secretory vesicles, Golgi apparatus, plasma membrane
Rough ER, Golgi apparatus, secretory vesicles, plasma membrane Proteins are synthesized in the rough ER, modified in the Golgi apparatus, and carried in secretory vesicles to the plasma membrane, where they are secreted.
What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane? Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores. Membrane of the endoplasmic reticulum is produced in the nucleolus and leaves the nucleus through the nuclear pores. The nuclear pores are connections between the nuclear membrane and the endoplasmic reticulum that permit ribosomes to assemble on the surface of the ER. The nucleolus contains messenger RNA (mRNA), which crosses the nuclear envelope through the nuclear pores. None of the listed responses is correct.
Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores. Proteins and ribosomal RNA are assembled into ribosomal subunits in the nucleolus.
Choose the best description of the cell cytoskeleton. The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components. The cell cytoskeleton serves as permanent scaffolding to anchor cell components into position within the cell cytoplasm. The cell cytoskeleton is similar to an animal skeleton in providing rigid internal support and structure to the cell.
The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components.
During a pulse-chase experiment, photographic emulsions were prepared at different times during the chase, and radioactive spots were detected at the following times and locations: 5 minutes: rough ER; 10 minutes: Golgi apparatus; 40 minutes: endosomes; 70 minutes: lysosomes; 140 minutes: lysosomes. Which of the following conclusions can be drawn from these results? The proteins did not travel through the Golgi apparatus. The proteins were secreted. The final destination of the proteins was the lysosome. The proteins traveled from lysosomes to endosomes.
The final destination of the proteins was the lysosome This conclusion can be drawn from the results, since the radioactive spots were last detected at the lysosome, which is not a secretory vesicle.
Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? The intestinal cells are bound together by the extracellular matrix. The intestinal cells are bound together by tight junctions. The intestinal cells are bound together by gap junctions. The intestinal cells are fused together into one giant cell. The intestinal cells are bound together by plasmodesmata.
The intestinal cells are bound together by tight junctions. The membranes of neighboring cells are actually fused at a tight junction, forming a seal that prevents the leakage of extracellular fluid across the layer of epithelial cells.
Which statement correctly describes the nuclear envelope of a eukaryotic cell? The nuclear envelope is a single membrane, consisting of a phospholipid bilayer. Plasmadesmosomes in the nuclear envelope permit the exchange of macromolecules between the nucleus and the cytoplasm. All of the proteins of the cell are synthesized on ribosomes bound on the nuclear envelope. The nuclear envelope is continuous with the endoplasmic reticulum. The outer layer of the nuclear envelope is coated with laminin.
The nuclear envelope is continuous with the endoplasmic reticulum.
A dish of animal cells was grown in the presence of radioactive phosphorous. The phosphorous largely ended up in nucleotides inside the actively growing animal cells. In which cellular structure or structures would you predict the majority of the radioactive phosphorous to accumulate? The nucleus Rough endoplasmic reticulum The Golgi apparatus Rough endoplasmic reticulum and Golgi apparatus The Golgi apparatus and the nucleus
The nucleus Large numbers of nucleotides would be used to make new DNA as the cells grew, and the DNA is housed in the nucleus.
Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER). The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes. Smooth ER is part of the endomembrane system of the eukaryotic cell, and rough ER is not. Rough ER consists of a network of membranous tubules and sacs called cisternae, whereas smooth ER is less complex.
The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.
A particular cell has a nucleus and chloroplasts in addition to the fundamental structures required by all cells. Based on this information, this cell could be __________. a cell from the intestinal lining of a cow a yeast (fungus) cell a cell from a pine tree a photosynthetic protist cell or a plant cell a bacterium
a photosynthetic protist cell or a plant cell Some protists (such as algae) can photosynthesize, and so can plants. As both the protists and plants are eukaryotes, they contain organelles.
Consider two cells with the same volume but with very different surface areas due to differences in their shapes. The cell with the larger surface area is likely to __________. have a very high metabolic rate be nearly spherical in shape be involved in the rapid uptake of compounds from the cell's environment be a prokaryotic cell be buried deep in the interior of an organism
be involved in the rapid uptake of compounds from the cell's environment The high surface area is likely to be associated with high transport rates of compounds across the plasma membrane. The greater the surface area, the greater the potential for transport.
Which of the following choices correctly matches a tool and its proper application? scanning electron microscopy (SEM) to study the detailed movements of living cells transmission electron microscopy (TEM) to study the movement of organelles within a living cell cell fractionation to study the function of specific organelles light microscopy to study the internal structure of cilia transmission electron microscopy (TEM) to study the surfaces of preserved cells
cell fractionation to study the function of specific organelles Cell fractionation can be used to separate different organelles to study their function separate from the rest of the cell.
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell? capsule pili cell wall flagella nucleoid region
cell wall The cell wall is a rigid supporting structure.
Which of the following correctly matches an organelle with its function? central vacuole ... storage lysosome ... movement nucleus ... cellular respiration ribosome ... manufacture of lipids mitochondrion ... photosynthesis
central vacuole ... storage plant cells have a central vacuole, whereas most animal cells have several smaller vacuoles located throughout the cytoplasm.
Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? cellulose fibers in the cell wall components of the cytoskeleton membrane proteins of the inner nuclear envelope free ribosomes and ribosomes attached to the ER
components of the cytoskeleton
Chloroplasts and mitochondria are thought to be of prokaryotic origin. One piece of evidence that supports this hypothesis is that these organelles contain prokaryotic-like ribosomes. These ribosomes are probably most similar to ribosomes found __________. on the rough ER free in the cytoplasm of eukaryotes in bacterial cells free in the cytoplasm of eukaryotes and on the rough ER free in the cytoplasm of eukaryotes, on the rough ER, and in bacterial cells
in bacterial cells Like the ribosomes in bacteria, the ribosomes in the mitochondria are smaller than those found free in the cytoplasm or bound to endoplasmic reticulum in the eukaryotes.
A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________. on free cytoplasmic ribosomes in the ribosomes of the mitochondria in the rough endoplasmic reticulum in the smooth endoplasmic reticulum in the plasma membrane
in the rough endoplasmic reticulum All of the membrane proteins of the endomembrane systems are made in the rough ER.
Which organelle plays a role in intracellular digestion? chloroplast lysosome Golgi apparatus plasmodesma ribosome
lysosome The prefix "lyso-" means decomposition.
The cilia and flagella of eukaryotic cells are composed of _____. pili microfilaments intermediate filaments tonofilaments microtubules
microtubules Eukaryotic cilia and flagella are composed of microtubules.
Which of these are hollow rods that shape and support the cell? chloroplasts microtubules plasma membrane peroxisomes microfilaments
microtubules Microtubules are rods that also play a role in organelle movement.
Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the lysosomes. endoplasmic reticulum. mitochondria. peroxisomes. ribosomes.
mitochondria.
Which of these organelles carries out cellular respiration? mitochondrion ribosomes smooth endoplasmic reticulum chromatin nucleolus
mitochondrion Mitochondria convert the chemical energy of organic molecules to chemical energy in the form of ATP.
Where is a bacterial cell's DNA found? ribosomes nucleus peroxisome nucleoid region capsule
nucleoid region Bacteria lack a nucleus; their DNA is found in the nucleoid region.
Ribosomal subunits are manufactured by the _____. nucleolus peroxisome rough endoplasmic reticulum smooth endoplasmic reticulum lysosome
nucleolus Ribosomes are manufactured by the nucleolus.
Which of these organelles produces H2O2 as a by-product? peroxisome flagellum nucleus centrioles mitochondrion
peroxisome Peroxisomes produce hydrogen peroxide as a by-product of their metabolic processes.
Which cell would be best for studying lysosomes? phagocytic white blood cell bacterial cell nerve cell muscle cell
phagocytic white blood cell
Mitochondria are found in _____. all cells animal cells only plant cells only plant and animal cells animal cells and prokaryotic cells, but not plant cells
plant and animal cells All eukaryotic cells, including plant and animal cells, contain mitochondria.
The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell. plasma membrane nucleoid region ribosome pili cell wall
plasma membrane The plasma membrane is selectively permeable.
The _____ is a selective barrier, regulating the passage of material into and out of the cell. lysosome chloroplast nuclear envelope plasma membrane nucleus
plasma membrane The plasma membrane regulates the passage of material into and out of the cell.
Dye injected into a plant cell might be able to enter an adjacent cell through __________. a tight junction a microtubule plasmodesmata a cell wall a gap junction
plasmodesmata The cell walls of plant cells contain numerous channels, with strands of cytoplasm passing through them and connecting one cell's cytoplasm to that of an adjacent cell.
What is a function of a bacterium's capsule? protection propulsion DNA storage protein synthesis
protection A bacterium's capsule has a protective role.
Which of the following is present in a prokaryotic cell? chloroplast mitochondrion ribosome nuclear envelope ER
ribosome
In a bacterium, where are proteins synthesized? ribosomes nucleus peroxisome nucleoid region capsule
ribosomes Ribosomes are involved in the manufacture of polypeptides (proteins).
Which of these organelles manufactures proteins bound for secretion out of the cell? Golgi apparatus nucleolus lysosomes rough endoplasmic reticulum
rough endoplasmic reticulum The ribosomes associated with the rough ER synthesize secretory proteins bound for the exterior of the cell. Further processing and packaging occurs in the Golgi apparatus.
You would expect a cell with an extensive Golgi apparatus to __________. secrete large amounts of protein absorb nutrients in the GI tract store large quantities of ions move rapidly make large amounts of ATP
secrete large amounts of protein The Golgi apparatus modifies and sorts the lipids and proteins produced in the ER. Cells that secrete large amounts of material require an extensive Golgi apparatus.
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells? smooth endoplasmic reticulum rough endoplasmic reticulum nuclear envelope Golgi apparatus
smooth endoplasmic reticulum
Where is calcium stored? rough endoplasmic reticulum microtubules mitochondria smooth endoplasmic reticulum centrioles
smooth endoplasmic reticulum In addition to storing calcium, the smooth ER also plays a role in detoxification and lipid synthesis.
A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________. store large quantities of water import and export large quantities of protein actively secrete large quantities of protein synthesize large quantities of lipids
synthesize large quantities of lipids
A substance moving from outside the cell into the cytoplasm must pass through __________. the nucleus a microtubule the plasma membrane the endomembrane system a ribosome
the plasma membrane The plasma membrane defines the boundary between the cytoplasm and the outside of the cell.
Which of these cell junctions form a barrier to the passage of materials? plasmodesmata gap (communicating) junctions keratin fibers desmosomes (anchoring junctions) tight junctions
tight junctions Tight junctions form a barrier that prevents fluids from moving between cells
Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____. translation of an RNA nucleotide sequence into a sequence of amino acids transferring of information from DNA to messenger RNA removal of introns from RNA and the stitching together of exons linking of nucleotides to form a polypeptide translation of a DNA nucleotide sequence into a sequence of amino acids
transferring of information from DNA to messenger RNA Transcription is the first of the two main steps of protein synthesis.
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic? whether or not the cell contains DNA whether or not the cell is partitioned by internal membranes whether or not the cell carries out cellular metabolism the presence or absence of a rigid cell wall the presence or absence of ribosomes
whether or not the cell is partitioned by internal membranes Prokaryotic cells lack any internal membranous compartmentalization.