Biology 1 (Biology 1610) CH.6 "A tour of the cell."
The word endoplasmic means "__________ _______ _______________," and reticulum is Latin for "_________ ________."
"within the cytoplasm", "little net."
There are two types of nucleic acids, what are they?
1. Deoxyribonucleic acid (DNA) 2. Ribonucleic acid (RNA)
Central vacuoles in plant cells contain 3 substances, what are they?
1. H2O (water) 2. Ions (NaCl) 3. Pigments
In eukaryotic cells, protein synthesis occurs in two main steps:
1. Information is transferred from DNA to mRNA. 2. mRNA carries the information received out of the nucleus to the ribosome to be translated into a sequence of amino acids which are linked to form a polypeptide.
A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in which of the following structural elements? A. extracellular matrix B. microtubules C. microfilaments D. intermediate filaments
A
A newly synthesized protein destined for secretion from a eukaryotic cell will generally follow which of the pathways listed below? A. rough ER →→ Golgi →→ transport vesicle →→ plasma membrane B. Golgi →→ rough ER →→ lysosome →→ transport vesicle →→ plasma membrane C. rough ER →→ lysosome →→ transport vesicle →→ plasma membrane D. rough ER →→ Golgi →→ transport vesicle →→ nucleus
A
An organelle in a newly discovered cell contains thylakoids, DNA, and ribosomes. These findings suggest that this organelle is most likely similar to which of the following organelles? A. chloroplasts B. nuclei C. mitochondria D. lysosomes
A
Asbestos is a material that was extensively used in construction for decades. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by phagocytosis, but are not able to degrade it. Toxicity most likely results from accumulation of asbestos in which of the following organelles? A. lysosomes B. the Golgi apparatus C. nuclei D. peroxisomes
A
Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules into the nucleus? A. ribosomal proteins B. phospholipids C. mRNAs D. rRNAs
A
Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER) A. The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes. B. Rough ER consists of a network of membranous tubules and sacs called cisternae, whereas smooth ER is less complex. C. Smooth ER is part of the endomembrane system of the eukaryotic cell, and rough ER is not.
A
In addition to making secretory proteins, it is a membrane factory for the cell; it grows in place by adding membrane proteins and phospholipids to its own membrane. A. Rough ER B. Smooth ER C. Nuclear Envelope D. Nucleus
A
Passive leakage of partially digested material from the small intestine into the human abdominal cavity may result from defects in which of the following type of intercellular junction? A. tight junctions B. desmosomes C. plasmodesmata D. gap junctions
A
Select the correct statement describing cellular structure or function. A. Plant and animal cells both carry out cellular respiration, producing ATP. B. Only plant cells contain chloroplasts, and only animal cells contain mitochondria. C. Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell.
A
_____ are the sites of protein synthesis. A. Ribosomes B. Golgi apparatuses C. Mitochondria D. Microfilaments E. Peroxisomes
A
A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken place? A. Passive transport B. Active transport C. Osmosis
A (A 25,000-dalton protein is small enough to diffuse through nuclear pores without any expenditure of energy.)
Which organelle plays a role in intracellular digestion? A. lysosome B. chloroplast C. ribosome D. plasmodesma E. Golgi apparatus
A (The prefix "lyso-" means decomposition.)
A young child who suffers from a metabolic disease is always tired and fatigued. Which of the following organelles is most likely malfunctioning in this disease? A. Golgi apparatus B. mitochondria C. lysosomes D. smooth endoplasmic reticulum
B
The _____ is composed of DNA and protein. A. mitochondrion B. chromatin C. ribosome D. flagellum E. centriole
B
_____ is/are identical in structure to centrioles. A. Microfilaments B. Basal bodies C. Nuclear envelopes D. Chromatin E. Mitochondria
B
Which of these organelles carries out cellular respiration? A. ribosomes B. mitochondrion C. chromatin D. nucleolus E. smooth endoplasmic reticulum
B (Mitochondria convert the chemical energy of organic molecules to chemical energy in the form of ATP.)
A cell with a predominance of smooth endoplasmic reticulum is most likely specialized to carry out which of the following processes? A. active secretion of large quantities of protein B. storage of large quantities of water C. synthesis of large quantities of lipids D. import and export large quantities of protein
C
A particular cell contains the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. Based on this composition, it could be a cell from which of the following organisms? A. a plant, but not an animal B. a bacterium, but not a eukaryote C. nearly any eukaryotic organism D. an animal, but not a plant
C
An early step in the evolution of eukaryotic cells most likely involved which of the following events? A. endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into chloroplasts B. endosymbiosis of a photosynthetic archaeal cell in a larger bacterial host cell to escape toxic oxygen-the anaerobic archaea evolved into chloroplasts C. endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria D. evolution of an endomembrane system and subsequent evolution of mitochondria from a portion of the smooth endoplasmic reticulum
C
Cells with high rates of protein synthesis have particularly large numbers of ________________ as well as prominent nucleoli. A. Chromosomes B. Enzymes C. Organelles D. Ribosomes
D
Motor proteins provide for molecular motion in cells by interacting with which of the following cellular structures? A. cellulose fibers in the cell wall B. membrane proteins of the inner nuclear envelope C. free ribosomes and ribosomes attached to the ER D. components of the cytoskeleton
D
Ribosomal subunits are manufactured by the _____. A. peroxisome B. smooth endoplasmic reticulum C. rough endoplasmic reticulum D. nucleolus E. lysosome
D
The cilia and flagella of eukaryotic cells are composed of _____. A. microfilaments B. intermediate filaments C. pili D. microtubules E. tono filaments
D
Which of the following molecules is required by cells to assemble cilia or flagella? A. actin B. laminin C. intermediate filaments D. tubulin
D
Where is calcium stored? A. microtubules B. centrioles C. rough endoplasmic reticulum D. smooth endoplasmic reticulum E. mitochondria
D (In addition to storing calcium, the smooth ER also plays a role in detoxification and lipid synthesis.)
Which of these organelles manufactures proteins bound for secretion out of the cell? A. nucleolus B. Golgi apparatus C. lysosomes D. rough endoplasmic reticulum
D (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.)
Each chromosome is made up of ________ tightly coiled many times around proteins called ___________ that support its structure.
DNA, histones
A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based on this information only, the organism is most likely to be ________. A. a motile bacterium B. a nonmotile prokaryote C. a motile archaea D. a nonmotile eukaryote E. a motile eukaryote
E
All cells share certain basic features: A. Cell membrane B. Cytosol C. Chromosomes D. Ribosomes E. All the above
E
Which of these are hollow rods that shape and support the cell? A. plasma membrane B. peroxisomes C. chloroplasts D. microfilaments E. microtubules
E (Microtubules are rods that also play a role in organelle movement.)
Which of the following functions is NOT associated with the cytoskeleton in eukaryotic cells? A. maintaining the position of the nucleus in the cell B. the beating of cilia or flagella C. determining the shape of animal cells D. the contraction of muscle cells in animals E. Movement of RNA molecules from the nucleus to the cytoplasm
E (RNA molecules exit the nucleus via nuclear pores.)
Which of the following correctly matches an organelle with its function? A. ribosome with the manufacture of lipids. B. nucleus with cellular respiration. C. lysosome with movement. D. mitochondrion with photosynthesis. E. central vacuole with storage.
E (plant cells have a central vacuole, whereas most animal cells have several smaller vacuoles located throughout the cytoplasm.)
____________________ is the ability of plant to transform solar energy into sugars and oxygen.
Photosynthesis
The smooth ER is a place where ________ are synthesized. The rough ER is a place where __________ are synthesized.
lipids, proteins
The _______________ provide the place on top of which proteins can move.
microtubules
A ______________ is formed by two sub-units. A small sub-unit and a large sub-unit. Its function is translating the information that is stored in the mRNA into proteins.
ribosome
What makes up the endomembrane system?
1. Nuclear envelope 2. Rough ER 3. Smooth ER 4. Golgi apparatus 5. Lysosomes 6. Plasma membrane
There are two processes that occur in the lysosome, what are they?
1. Phagocytosis 2. Autophagy (Phago and phagy translate: "to eat.")
What are the 2 functions of pigments?
1. Protect against UV radiation (sunscreen) 2. Give color to plant tissues. (Ex: Flowers attract pollinators)
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is abundant in liver cells and primarily responsible for detoxification processes? A. smooth endoplasmic reticulum B. Golgi apparatus C. nuclear envelope D. rough endoplasmic reticulum
A
Uses information from the DNA to make proteins: A. Ribosomes B. Chromosomes C. Nucleus D. Nucleolus
A
Which of the following areas in bacterial cells best describes where chromosomal DNA is generally localized? A. in the nucleoid B. associated with ribosomes C. in mitochondria D. in a membrane-enclosed nucleus
A
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic? A. whether or not the cell is generally partitioned by internal membranes. B. whether or not the cell carries out cellular metabolism. C. the presence or absence of a rigid cell wall. D. the presence or absence of ribosomes. E. whether or not the cell contains DNA.
A
Which of the following parameters is most likely to limit the maximum size of a cell? A. the ratio of surface area to volume of cytoplasm B. the absence of a nucleus C. the volume of the endomembrane system D. the number of mitochondria in the cytoplasm
A
_____________ is the actual translation of "whip." They are attached to the outside of the cell and help the cell to propel or move forward. A. Flagella B. Fimbriae C. cytosol D. Cell wall
A
_________________ are the sites of cellular respiration, the metabolic process that uses oxygen to drive the generation of ATP by extracting energy from sugars, fats, and other fuels. A. Mitochondria B. Golgi apparatus C. Lysosomes D. Endoplasmic reticulum
A
____________________ are thin solid rods. They are also called actin because they are built from molecules of actin, a globular protein. Their structural role in the cytoskeleton is to bear tension (pulling forces). They are well known for their role in cell motility. A. Microfilaments B. Microtubules C. Intermediate filaments D. Cytoskeleton
A
What is the first step in a pulse-chase experiment? A. Incubating cells with a labeled molecule B. Examining cells for the location of the labeled molecules C. Preparing cells for electron microscopy D. Incubating cells with an unlabeled molecule
A (Cells are first "pulsed" with a large amount of labeled material for a short time.)
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? A. digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm B. enzymes for the breakdown of the food are delivered to the food vacuole from the cytosol C. proteins for digestion of the food are made by ribosomes in the Golgi apparatus D. proteins for digestion of the food particle were initially processed in mitochondria E. the membrane of the food vacuole is derived from the cell wall
A (Digestion occurs within a vesicle. If the digestive enzymes were in the cytosol, they might degrade essential components of the cell.)
In experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules? A. To make the proteins easy to see B. To target the proteins to the nucleus C. To make the proteins bigger D. To give the protein molecules energy
A (Fluorescent tags make the location of the proteins easy to visualize.)
What scientific hypotheses can be tested by a pulse-chase experiment? A. Movement of molecules through a cell over time B. Solubility of a molecule C. The amino acid sequence of a protein D. The steady-state amount of protein in a cell
A (Pulse-chase experiments allow for the tracking of molecules in a cell over time.)
Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. After injecting these fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the cytoplasm. Which of the following conclusions can be drawn from these results? A. Only one of the two fusion proteins possesses a nuclear localization signal. B. Nucleoplasmin does not have a nuclear localization signal. C. One of the fusion proteins entered the nucleus by passive transport. D. The cytoplasmic protein contains a nuclear localization signal.
A (The nuclear localization signal is only present in the fusion protein that enters the nucleus.)
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? A. The final destination of the proteins was the lysosome. B. The proteins traveled from lysosomes to endosomes. C. The proteins did not travel through the Golgi apparatus. D. The proteins were secreted.
A (This conclusion can be drawn from the results, since the radioactive spots were last detected at the lysosome, which is not a secretory vesicle.)
A cell with a predominance of rough endoplasmic reticulum is most likely involved in which of the following processes? A. producing large quantities of proteins in the cytosol B. producing large quantities of proteins for secretion C. producing large quantities of carbohydrates for storage in the vacuole D. producing large quantities of carbohydrates to assemble an extensive cell wall matrix
B
A major difference between prokaryotic and eukaryotic cells: A. Prokaryotes are generally much larger than Eukaryotes. B. Eukaryotes have a nucleus, prokaryotes have a nucleoid. C. Prokaryotes have membrane bound structures, eukaryotes do not. D. A and B are correct.
B
Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules out of the nucleus? A. DNA B. mRNA C. amino acids D. phospholipids
B
Here a type of RNA called ribosomal RNA (rRNA) is synthesized from genes in the DNA. Also, proteins imported from the cytoplasm are assembled with rRNA into large and small subunits of ribosomes. Where do these actions take place? A. In the nucleus B. In the nucleolus C. In the Golgi apparatus D. In the lysosomes
B
Nucleic acids are the cells: A. Memory molecules B. Information molecules C. Power/energy molecules D. Breakdown substances molecules
B
One difference between eukaryotic and prokaryotic cells is that eukaryotic cells: A. have DNA, which is lacking in prokaryotic cells. B. have membrane-enclosed organelles, which are lacking in prokaryotic cells. C. lack the complexity seen in prokaryotic cells. D. are enclosed by a membrane, which is lacking in prokaryotic cells.
B
Organisms of the domains Bacteria and Archaea consist of: A. Eukaryotic cells B. Prokaryotic cells C. Plant cells D. Animal cells
B
What is NOT a function of the cytoskeleton? A. Gives mechanical support to the cell and maintain its shape. B. Prevents chromosomes from separating. C. Provides anchorage for many organelles and even cytosolic enzyme molecules. D. Involved in cell motility (movement).
B
Which molecules do not normally cross the nuclear membrane? A. Proteins B. DNA C. Nucleotide triphosphates D. mRNA
B
Which of the following is present in a prokaryotic cell? A. chloroplast B. ribosome C. mitochondrion D. nuclear envelope
B
Which of the following is present in a prokaryotic cell? A. mitochondrion B. ribosome C. nuclear envelope D. chloroplast
B
Which of the following statements best describes one major difference between prokaryotic cells and eukaryotic cells? A. Eukaryotic cells have flagella, while prokaryotic cells do not. B. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not. C. Prokaryotic cells are generally larger than eukaryotic cells. D. Prokaryotic cells have cell walls, while eukaryotic cells do not.
B
Which of the following structures are found in plant, animal, and bacterial cells? A. mitochondria B. ribosomes C. chloroplasts D. lysosomes
B
Which of the following structures is independent of the endomembrane system in eukaryotic cells? A. nuclear envelope B. chloroplast C. Golgi apparatus D. plasma membrane
B
Which organelle is a membranous sac of hydrolytic enzymes that many eukaryotic cells use to digest (hydrolyze) macromolecules. A. Golgi apparatus B. Lysosome C. Mitochondria D. Endoplasmic reticulum
B
Which structure is common to plant and animal cells? A. central vacuole B. mitochondrion C. chloroplast D. centriole
B
Which structure is part of the endomembrane system? A. mitochondrion B. Golgi apparatus C. chloroplast D. centrosome
B
____________ are tiny hairs that help provide adhesion to a surface. Example: sometimes they trap oxygen so your cells can breathe. A. Flagella B. Fimbriae C. Cytosol D. Cell wall
B
_____________________ shape and support the cell and also serve as tracks along which organelles equipped with motor proteins can move, guide vesicles from the ER to the Golgi apparatus and from the Golgi to the plasma membrane, and are also involved in the separation of chromosomes during cell division. A. Microfilaments B. Microtubules C. Intermediate filaments D. Cytoskeleton
B
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? A. Rough ER B. Exterior of the cell C. Golgi apparatus D. Secretory vesicles
B (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? Large proteins containing a nuclear localization signal (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy. A. True B. False
B (Cytoplasmic proteins called importins bind to large proteins containing an NLS and mediate their transport across the nuclear membrane through an active transport (energy-requiring) process.)
True or false? Proteins produced during the "chase" phase of a pulse-chase experiment are labeled with radioactive material. A. True B. False
B (During the chase phase, cells are provided with a large amount of nonradioactive material, so they are not labeled.)
At the pores, the nuclear side of the envelope is lined by a netlike array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope. A. Pore complex B. Nuclear matrix C. Nuclear lamina D. None of the above
C
Disruption of the function of which of the following organelles would result in a dramatic decrease in ATP synthesis in eukaryotic cells? A. Golgi apparatus B. peroxisome C. mitochondrion D. lysosome
C
Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that the cell is actively producing large amounts of which of the following molecules? A. nucleic acids B. polysaccharides C. proteins D. lipids
C
If you are provided with a cube of modeling clay, which of the following changes to the shape of this cube will decrease its surface area relative to its volume? A. Stretch the cube into a long, shoebox shape. B. Flatten the cube into a pancake shape. C. Round the clay up into a sphere. D. Cut the cube into eight smaller cubes.
C
In a prokaryotic cell, the DNA is concentrated in a region that is not membrane-enclosed. What is this region called? A. Nucleus B. Cytosol C. Nucleoid D. Plasma membrane
C
Inside the chloroplast is another membranous system in the form of flattened, interconnected sacs called ______________. In some regions, they are stacked like poker chips; each stack is called a ____________. The fluid outside the thylakoids is the _____________, which contains the chloroplast DNA and ribosomes as well as many enzymes. A. Granum, thylakoids, stroma B. Stroma, thylakoids, granum C. Thylakoids, granum, stroma D. Thylakoids, stroma, granum
C
Tay-Sachs disease is a human genetic disorder that results in cellular accumulation of very large, complex, undigested lipids. Which of the following organelles is most likely defective in Tay-Sachs disease? A. the rough endoplasmic reticulum B. the smooth endoplasmic reticulum C. the lysosome D. the Golgi apparatus
C
The mitochondria is composed of what 5 areas: A. Outer membrane, thylakoid, Ribosomes, inner membrane, matrix B. Outer membrane, intermembrane space, inner membrane, granum, matrix C. Outer membrane, intermembrane space, inner membrane, cristae, matrix D. Inner-outer membrane, thylakoid, granum, stroma, ribosomes
C
The nuclear lamina is an array of intermediate filaments that line the inner surface of the nuclear membrane. Disassembly of the lamina by chemical treatment would most likely result in which of the following consequences? A. a loss of genetic information from chromosomes B. closing of nuclear pores C. a change in the shape of the nucleus D. the inability of the nucleus to divide during cell division
C
These processes include synthesis of lipids, metabolism of carbohydrates, detoxification of drugs and poisons, and storage of calcium ions. A. Lysosomes B. Rough ER C. Smooth ER D. Both B and C
C
This process in __________________ converts solar energy to chemical energy by absorbing sunlight and using it to drive the synthesis of organic compounds such as sugars from carbon dioxide and water. A. Ribosomes B. Chromosomes C. Chloroplasts D. Mitochondria
C
When H. V. Wilson exposed two species of differently pigmented sponges to a chemical that disrupted intercellular junctions, the cells of the sponges dissociated. Wilson then removed the chemical that caused dissociation and mixed the cells of the two species. He found that the sponges reassembled and that the cells from one species did not interact or form associations with the cells of the other species. Which of the following statements provides the most plausible explanation for the results of this experiment? A. The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment. B. One cell functioned as an organizer for each organism, thereby attracting only cells of the same species. C. The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge. D. The two species of sponge had different enzymes that functioned in the reassembly process.
C
Where does the translation of mRNA into proteins occur? A. Nucleus B. Nucleolus C. Cytoplasm D. Chromosome
C
Which of the following options best depicts the flow of information when a gene directs the synthesis of a cellular component? A. DNA →→ amino acid →→ RNA →→ protein B. protein →→ RNA →→ DNA C. DNA →→ RNA →→ protein D. RNA →→ DNA →→ RNA →→ protein
C
Which of the following organelles is primarily responsible for the production and modification of polysaccharides that will be secreted? A. lysosome B. mitochondrion C. Golgi apparatus D. peroxisome
C
Which of the following organelles often occupy the majority of the volume of a plant cell? A. chloroplast B. Golgi apparatus C. central vacuole D. lysosome
C
Which of the following pairs of organism groups consist solely of prokaryotic cells? A. Archaea and fungi B. Bacteria and protists C. Bacteria and Archaea D. Bacteria and Eukarya
C
Which structure is common to plant and animal cells? A. chloroplast B. central vacuole C. mitochondrion D. centriole
C
Which structure is part of the endomembrane system? A. mitochondrion B. centrosome C. Golgi apparatus D. chloroplast
C
Within the nucleus, the DNA is organized into discrete units called ___________________, structures that carry the genetic information. Each structure contains one long DNA molecule associated with many proteins, including small basic proteins called histones. A. Ribosomes B. Chromatin C. Chromosomes D. Both B and C
C
_________________ contain enzymes that remove hydrogen atoms from various substrates and transfer them to oxygen (O2), producing hydrogen peroxide (H2O2) as a by-product. A. Chloroplasts B. Oxygen enzymes C. Peroxisomes D. Mitochrondrion
C
___________________ are only found in the cells of some animals, including vertebrates. Specialized for bearing tension, are more permanent fixtures of cells, are especially sturdy and play an important role in reinforcing the shape of a cell and fixing the position of certain organelles. It seems to function together as the permanent framework of the entire cell. A. Microfilaments B. Microtubules C. Intermediate filaments D. Cytoskeleton
C
Which of the following is a common trait of chloroplasts and mitochondria? A. both are surrounded by a single membrane B. both are found in plant and animal cells C. both contain their own DNA D. both reproduce by meiosis E. proteins for both are synthesized on ribosomes in the rough ER
C (Mitochondria and chloroplasts contain their own DNA and ribosomes.)
Which one of the following statements about the endomembrane system is correct? A. Most of the phospholipids of the endomembrane system are synthesized in the mitochondria. B. Mitochondria function in the modification and sorting of lipids and proteins. C. Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system. D. The endoplasmic reticulum is continuous with the plasma membrane. E. Ribosomes move lipids and proteins among the different organelles of the endomembrane system.
C (Proteins that will be secreted are always enclosed by some membrane of the endomembrane system until they are secreted.)
Which statement correctly describes an endomembrane function? A. Secretory proteins in transit from one part of the cell to another are carried in lysosomes. B. The lumen of the endoplasmic reticulum (ER) is continuous with the cell nucleus. C. Products of the ER are usually modified during their transit from the cis to the trans region of the Golgi apparatus.
C (The cis and trans regions of the Golgi apparatus act as receiving and shipping departments. As molecules move from the cis to the trans face of the Golgi apparatus, they are usually modified.)
Which of the following statements about the nuclear envelope is false? A. Molecules pass into and out of the nucleus through nuclear pores. B. The nuclear envelope is composed of two lipid bilayers. C. The nuclear envelope is continuous with the Golgi apparatus. D. Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore complex.
C (the nuclear envelope is continuous with the endoplasmic reticulum.)
Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____. A. linking of nucleotides to form a polypeptide B. translation of a DNA nucleotide sequence into a sequence of amino acids C. removal of introns from RNA and the stitching together of exons D. transferring of information from DNA to messenger RNA E. translation of an RNA nucleotide sequence into a sequence of amino acids
D
For example, cells that move or contract have proportionally more _________________ per volume than less active cells. A. Nucleoli B. Golgi apparatus C. Chromosomes D. Mitochondria
D
We can think of the ___________ as a warehouse for receiving, sorting, shipping, and even some manufacturing. Here, products of the ER, such as proteins, are modified and stored and then sent to other destinations. A. Lysosomes B. Endoplasmic reticulum C. Mitochondria D. Golgi apparatus
D
Which cell would be best for studying lysosomes? A. muscle cell B. nerve cell C. bacterial cell D. phagocytic white blood cell
D
Which of the following statements best describes the function of the nuclear pore complex found in eukaryotic cells? A. It synthesizes the proteins required to copy DNA and make mRNA. B. It synthesizes secreted proteins. C. It assembles ribosomes from raw materials that are synthesized in the nucleus. D. It regulates the movement of proteins and RNAs into and out of the nucleus.
D
Mitochondria are found in __________. A. animal cells only B. animal cells and prokaryotic cells, but not plant cells C. plant cells only D. plant and animal cells E. all cells
D (Nearly all eukaryotic cells, including plant and animal cells, contain mitochondria.(
Where are ribosomes assembled? A. Nucleus B. Cytoplasm C. Nuclear pore D. Nucleolus
D (Once assembled, they leave the nucleolus, out the nuclear pore, and into the cytosol or attach to the ER.)
What path does a protein in the secretory pathway take, starting from its site of synthesis? A. Rough ER, secretory vesicles, Golgi apparatus, plasma membrane B. Golgi apparatus, rough ER, secretory vesicles, plasma membrane C. Plasma membrane, secretory vesicles, Golgi apparatus, rough ER D. Rough ER, Golgi apparatus, secretory vesicles, plasma membrane
D (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.)
When breaking down the Golgi apparatus there are two types of vesicles. There is a Golgi which is called Cis Golgi and a Golgi which is called Trans Golgi. Cis is a Latin word that means "on the same side." Trans is the Latin word that means "on the opposite side." On the same and opposite side of what exactly?
The Endoplasmic Reticulum
Inside of the nucleus, we have the DNA all supercoiled to form chromosomes that are coiled into a structure called ______________.
chromatin
