ch4
Which of the following produces and modifies polysaccharides that will be secreted?
Golgi apparatus
One advantage of light microscopy over transmission electron microscopy is that
Light microscopy allows you to view dynamic processes in living cells.
Which of the following structures plays a major role in making skin tissue water tight?
Tight junctions
If plant cells are grown on media containing radioactively labeled thymine for one generation, where will radioactively labeled macromolecules be detected?
in the nucleus, mitochondria, and chloroplasts
In muscle cells, which organelle sequesters Ca2+ from the cytosol?Choose one: -lysosome -endosome -rough ER -smooth ER -mitochondrion
-smooth ER In muscle cells, this specialized smooth ER is called the sarcoplasmic reticulum.
The smallest cell structures that would most likely be visible with a standard (not super-resolution) research-grade light microscope is
chloroplasts
Approximately what percentage of the volume of a typical eukaryotic cell is comprised of cytosol? Choose one: -10% -50% -80% -20%
-50% The volume of a typical eukaryotic cell is about 50% cytosol and the remaining 50% is occupied by membrane-bound organelles.
Which of these organelles are surrounded by a double membrane?Choose one or more: A.nucleus B.chloroplast C.Golgi apparatus D.mitochondrion E.peroxisome F.lysosome
-A.nucleus, B.chloroplast, and D.mitochondrion The nuclear membranes most likely originated by invagination of the plasma membrane to form a two-layered envelope that surrounds the cell's DNA; mitochondria and chloroplasts evolved from bacteria that were engulfed by primitive eukaryotic cells.
How do the interiors of the ER, Golgi apparatus, endosomes, and lysosomes communicate with each other? Choose one: A. by open pores that allow ions to exit and enter the organelles B. by excreting hormones and other small signaling molecules C. by fusing with one another D. by small vesicles that bud off of one organelle and fuse with another E. They do not communicate with one another.
-D. by small vesicles that bud off of one organelle and fuse with another In this way, transport vesicles carry soluble cargo proteins, as well as the proteins and lipids that are part of the vesicle membrane, from one organelle to another.
Which organelle receives proteins and lipids from the endoplasmic reticulum, modifies them, and then dispatches them to other destinations in the cell? Choose one: -nucleus -peroxisome -mitochondrion -Golgi apparatus -endosome
-Golgi apparatus Soluble proteins and pieces of membrane enter the Golgi network via transport vesicles derived from the ER. Proteins exit from the Golgi network in transport vesicles destined for either the cell surface or another organelle of the endomembrane system.
Which of these strategies do prokaryotic cells use to isolate and organize their chemical reactions? Choose one: -confining the proteins required for different metabolic processes within the plasma membrane -confining proteins required for different metabolic processes within different membrane-enclosed compartments -None; prokaryotes do not regulate their metabolic processes. -aggregating proteins into multicomponent complexes that form biochemical subcompartments with distinct functions -None; these strategies are used only by eukaryotic cells.
-aggregating proteins into multicomponent complexes that form biochemical subcompartments with distinct functions The formation of these subcompartments can involve the participation of scaffold proteins that bring together components involved in a particular reaction sequence, such as DNA synthesis.
Which organelle is the major site of new membrane synthesis in a cell?Choose one: -peroxisome -nucleus -endoplasmic reticulum -Golgi apparatus -mitochondrion
-endoplasmic reticulum In addition to synthesizing many proteins, the ER serves as the major site for the synthesis of new membranes.
Which organelle sorts ingested molecules and recycles some of them back to the plasma membrane? Choose one: -Golgi apparatus -endoplasmic reticulum -lysosome -peroxisome -endosome
-endosome Eukaryotic cells continually ingest bits of their plasma membrane, along with small amounts of extracellular fluid, in the process of pinocytosis. Most material taken up by cells in this manner is rapidly delivered to endosomes, which serve as sorting stations for ingested material.
Which organelle is essentially a small sac of digestive enzymes that functions in degrading worn-out organelles, as well as macromolecules and particles taken into the cell by endocytosis?Choose one: -nucleus -lysosome -peroxisome -Golgi apparatus -endosome
-lysosome Lysosomes are membranous sacs of hydrolytic enzymes that carry out the controlled intracellular digestion of both extracellular materials and worn-out organelles. They contain about 40 types of hydrolytic enzymes, including those that degrade proteins, nucleic acids, oligosaccharides, and lipids.
Which organelle contains enzymes used in a variety of oxidative reactions that break down lipids and destroy toxic molecules?Choose one: -endosome -endoplasmic reticulum -peroxisome -lysosome -mitochondrion
-peroxisome Peroxisomes are packed with enzymes that digest toxins and synthesize certain phospholipids, including those present in the myelin sheath surrounding nerve cell axons.
In a typical human secretory cell, which of the following membranes has the largest surface area? Choose one: -lysosome -smooth ER -plasma membrane -nuclear inner membrane -rough ER
-rough ER The rough ER is folded up to form an extensive maze of interconnected spaces. This organelle can, in some cases, compose about half of the total membrane present in the cell.
Endocrine cells that synthesize lipid hormones, such as steroids, contain extensive amounts of which of the following? Choose one: -rough ER -nucleus -smooth ER -Golgi apparatus -cytosol
-smooth ER The smooth ER is scanty in most cells but is highly developed for performing particular functions in others; for example, it is the site of steroid hormone synthesis in some endocrine cells of the adrenal gland.
Which of the following organelles is the site of steroid hormone synthesis in endocrine cells? Choose one: A. cytosol B. smooth endoplasmic reticulum C. mitochondrion D. nucleus
B. smooth endoplasmic reticulum The endoplasmic reticulum (ER) is the location of synthesis for proteins (rough ER) and many lipids including steroid hormones (smooth ER).
Which of the following are common traits of chloroplasts and mitochondria?
Both have their own DNA
A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its
Golgi apparatus and extracellular matrix.
Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. In animal cells, which of the following organelles contains these hydrolytic enzymes.
Lysosomes.
Which of the following structures will be found in nearly all eukaryotic cells?
Mitochondria
Which plant cell organelle contains it's own DNA and ribosomes
Mitochondrion
Which of the following statements about the cytoskeleton is true?
Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
A researcher disrupts cells and seperates subcellular components usuing centrifugation. Which of the following correctly lists the order in which cellular components will pellet when disrupted cell mixtures are centrifuged at increasingly higher speeds.
Nucleus, Mitochondria, Ribosomes
A cell with an abudance of free ribosomes is most likley carrying out which of the following processes.
Producing primarily cytoplasmic proteins.
Which one of the following statements about the endomembrane system is correct?
Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system.
Some key innovations is the evolution of eukaryotic cells from a prokaryotic ancestor are membrane-bound organelles. Which of the following organelles or features is a common structure shared by both eukaryotic cells and their prokaryotic ancestors?
Ribosomes.
A biologist wants to examine the surfaces of different types of cells in kidney tubules of small mammals. The cells in question have been extracted from animal and can be distinguished by external shape, size, and 3D characteristics. Which of the following would be the optimal method for her study.
Scanning Electron Microscopy.
What technique would be most appropreiate to use to observe the movments of condensed chromosomes during cell division.
Standard light microscopy.
which is a function of a plant cell vacuole?
Storage of toxic wastes, Provide turgor pressure to support the cell wall, Storage of food and nutrients.
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating very large, complex, undigested lipids. Which cellular organelle is likely to be defective in this condition?
The Lysosome
The cell walls of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic common to all of these extracellular structures?
They are constructed of polymers that are synthesized in the cytoplasm and then transported out of the cell.
Which organelles or structures are absent in plant cells?
centrosomes
In a liver cell, detoxifying alcohol and some other poisons, the enzymes of the preoxisome remove hydrogen from these molecules and
combine the hydrogen with oxygen molecules to generate hydrogen peroxide.
Motor proteins provide for molecular transport of materials in cells by interacting with what type(s) of cellular structures.
cytoskeletal structures
Which of the following molecules or structures may be found in eukaryotic cells but not in bacteria.
endoplasmic reticulum
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
gap junctions
Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through
gap junctions (electrical signal for contraction passes rapidly from one heart muscle to the next by this)
The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via what?
integrins
One advantage of light microscopy over transmission electron microscopy is that
light microscopy allows one to view dynamic processes in living cells.
What types of proteins are synthesized by the rough ER?
lysosomal proteins
Movement of vesicles within the cell depends on what cellular structures?
microtubules and motor proteins
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
mitochondria
The chemical reactions involved in respiration in prokaryotic and eukaryotic cells are virtually identical. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. In light of the endosymbiont theory for the evolutionary origin of mitochondria, where is most ATP synthesis likely to occur in prokaryotic cells?
on the plasma membrane
Which cell would be best for studying lysosomes?
phagocytic white blood cell
The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal cells. The most reasonable explanation for this observation is that
plant cells contain a large vacuole that reduces the volume of the cytoplasm.
When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion?
primary cell wall → plasma membrane → cytoplasm → vacuole
Which of the following statements correctly describes a function of the Golgi apparatus?
protein modification and sorting
Extracellular matrix proteins are produced by ribosomes in which part of a eukaryotic cell?
rough ER
Which structure is the site of the synthesis of proteins destined for export from the cell?
rough ER
Which of the following correctly describes the pathway taken by a protein destined for secretion from an animal cell?
rough ER → transport vesicle → Golgi → transport vesicle → plasma membrane
Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to
separate chromosomes during cell division
Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?
smooth ER
When subcellular components from disrupted cells are separated using centrifugation, the primary factor that determines whether a specific cellular component remains in the liquid solution or ends up in the pellet is
the relative size and weight of the component
Passive movement of fluids and bacteria from the interior of the small intestine through the space between cells of the intestinal wall can cause serious infection and medical complications. Defects in which of the following would be associated with such a condition?
tight junctions
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?
whether or not the cell is partitioned by internal membranes
Which membrane-enclosed organelles most likely evolved in a similar manner? Choose one: -mitochondria and the nucleus -mitochondria and the ER -the nucleus and the ER -chloroplasts and peroxisomes -mitochondria and the Golgi apparatus
-the nucleus and the ER The nuclear membranes and the membranes of the ER most likely originated by invagination of the plasma membrane; the outer nuclear membrane is actually continuous with the rough ER.
If a treatment were avaliable that would disrupt the nuclear lamina in living cells, what would you expect to be the most likley immediate consequence for the cell.
A change in the shape of the nucleus.
A cell has the following molecules and structures: Enzymes, DNA, Ribosomes, plasma membrane, chloroplast, and mitchondria. It could be.
A plant cell, but not an animal cell.
Which of the following organelles is surrounded by a single membrane? Choose one: A. Golgi apparatus B. mitochondria C. nucleus D. chloroplasts
A. Golgi apparatus The nucleus, mitochondria, and chloroplasts are each surrounded by a double membrane, and organelles like the Golgi apparatus, lysosomes, and the endoplasmic reticulum have a single membrane.
Cell fractionation is commonly used in biological research to
Isolate organelles to examine their biological functions.
Prokaryotes are classified as belonging to two different domains. What are the domains?
Bacteria and Archaea.
Which of the following organelles is NOT a part of the endomembrane system? Choose one: A. endoplasmic reticulum B. Golgi apparatus C. nucleus D. lysosomes
C. nucleus The endomembrane system is a set of organelles that extensively communicate via vesicle budding. The organelles in the system include the endoplasmic reticulum, the Golgi apparatus, endosomes, lysosomes, and peroxisomes.
Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. Which of the following hypotheses is most plausible in light of such structural similarities?
Cilia and flagella are derived from the centrioles.
Which structure is the synthesis of protiens deestined for export from the cell?
Rough ER
The outer membrane of the nucleus is continuous with the membrane of which other organelle? Choose one: A. endosome B. peroxisome C. mitochondrion D. endoplasmic reticulum E. Golgi apparatus
D. endoplasmic reticulum The nucleus, generally the most prominent organelle in eukaryotic cells, is surrounded by a double membrane known as the nuclear envelope. The outer nuclear membrane is continuous with the membrane of the endoplasmic reticulum (ER), a system of interconnected membranous sacs and tubes that often extends throughout most of the cell. The ER is the major site of synthesis of new membranes in the cell. The nuclear membranes and the membranes of the ER, Golgi apparatus, endosomes, and lysosomes most likely originated by invagination of the plasma membrane.
What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?
ER → Golgi → vesicles that fuse with plasma membrane
What is the primary reason that a modern transmission electron microscope (TEM) can resolve biological images as small as 2 nm, whereas 200 nm is the limit of resolution for a light microscope?
Electron beams have much shorter wavelengths than visible light
Comparison of samples from the liver of an alcoholic with samples from the liver of a non-drinker when examined by transmission electron microscopy would likely reveal that.
the liver of the alchoholic has exspansive smooth ER compared to th non-drinker's liver
