Which of the following is associated with the rough endoplasmic reticulum?
- lipid synthesis
- energy transfer
You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume?
- round the clay up into the sphere
- stretch the cube into a long, shoebox shape
- pinch the edges of the cube into small folds
- flatten the cube into a pancake shape
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle must be involved in this condition?
- the endoplasmic reticulum
- the lysosome
- the Golgi apparatus
In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and ….?
- use the hydrogen to breaks down hydrogen peroxide
- transfer the hydrogen to oxygen molecules to generate hydrogen peroxide
- combine the hydrogen with water molecules to generate hydrogen peroxide
- transfer the hydrogen to the mitochondria
The nucleolus is:
- the area in a prokaryote where the DNA is concentrated
- a membrane-bound organelle in the nucleus
- an area in the eukaryotic nucleus where ribosomes are constructed
- B and C
- A, B, and C
H. V. Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted the cell-cell interaction (cell junctions), and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species. How do you explain the results of Wilson's experiments?
- The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment.
- The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.
- One cell functioned as the nucleus for each organism, thereby attracting only cells of the same pigment.
- The two species of sponge had different enzymes that functioned in the reassembly process.
In Figure 04-01, the small dot-like structures covering one section of this membrane are:
Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles and ATP (because they knew the transport process requires energy). Yet, when they put everything together, there was no movement or transport of vesicles. What were they missing?
- motor proteins
- contractile microfilaments
- endoplasmic reticulum
- an axon
Which of the following relationships between cell structures and their respective functions is NOT correct?
- ribosomes - site of protein synthesis
- mitochondria - formation of ATP for the cell
- chloroplasts - chief site of sugar breakdown
- cell wall - support and protection
- nucleus - site of genetic control of information
The source of energy for a chloroplast is:
The Golgi apparatus has a polarity, or sidedness, to its structure and function. Which of the following statements correctly describes this polarity?
- Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
- Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
- Transport vesicles fuse with one side of the Golgi and leave from the opposite side.
- All of the listed responses correctly describe polarity characteristics of the Golgi function.
Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?
- Prokaryotes cannot secrete proteins because they lack ribosomes.
- The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes.
- Prokaryotes cannot secrete proteins because they lack an endomembrane system.
- Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.
Which organelle or structure is absent in plant cells?
Amoebae move by crawling over a surface (cell crawling), which involves _____.
- growth of actin filaments to form bulges in the plasma membrane
- cytoplasmic streaming
- setting up microtubule extensions that vesicles can follow in the movement of cytoplasm
- reinforcing the pseudopod with intermediate filaments
Thylakoids, DNA, and ribosomes are all components found in _____.
DNA is NOT located in which of the following?
- animal cells
- prokaryotic cells
- plant cells
Hooke was the first to observe cells under a simple microscope in the 1600s because he was looking at:
- cells that were naturally colored
- flagellated eukaryotic cells that were moving
- egg cells, which can be extraordinarily large
- plant cells in which the thick cell wall was clearly visible
- flagellated bacterial cells that were moving
Proteins destined to be secreted from the cell are often modified in the Golgi apparatus by the addition of:
- fatty acids
- amino acids
Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to _____.
- form cleavage furrows during cell division
- maintain the shape of the nucleus
- migrate by amoeboid movement
- separate chromosomes during cell division
Cyanide binds with at least one molecule involved in the producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the ____.
- endoplasmic reticulum
In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is the _____.
- size and weight of the component
- percentage of carbohydrates in the component
- presence or absence of lipids in the com
In metabolically active cells, you would expect to find a large number of:
- Golgi bodies
Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from _____.
- a plant but not an animal
- a bacterium
- nearly any eukaryotic organism
- an animal but not a plant
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?
- rough ER
- nuclear envelope
- Golgi apparatus
- smooth ER
Penicillin destroys bacteria by interfering with cell wall synthesis, resulting in:
- cell lysis
- organelle damage
- new cell wall synthesis
- immediate cell division
- inhibition of plasma membrane synthesis
The difference in lipid and protein composition between the membranes of the endomembrane system is largely determined by the ___?
- transportation of membrane lipids among the membranes of the endomembrane system by the small membrane vesicles
- synthesis of different lipids and proteins in each of the organelles of the endomembrane system
- function of the Golgi apparatus in sorting and directions membrane components
- modification of the membrane components once they reach their final destination
Which of the following statements about the cytoskeleton is true?
- although microtubules are common within the cell, actin filaments are rarely found outside of the nucleus.
- chemicals that block the assembly of the cytoskeleton would have little effect on on a cell’s response to external stimuli
- the cytoskeleton of eukaryotes is a static structure most resembling scaffolding used at constructions sites
- movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein in the red blood cells (RBCs). What do you suspect is the consequence of such a defect?
- an insufficient supply of ATP in the RBCs
- an insufficient supply of oxygen-transporting proteins in the RBCS
- adherence of RBCs to blood vessel walls, causing plaque formation
- abnormally shaped RBCs
Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will phagocytize asbestos, but are not able to degrade it. As a result, asbestos fibers accumulate in _____.
A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its _____.
- mitochondria and Golgi apparatus
- nuclear matrix and extracellular matrix
- Golgi apparatus and extracellular matrix
- nuclear pores and secretory vesicles
What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division?
- scanning electron microscopy
- transmission electron microscopy
- standard light microscopy
Which structure is common to plants and animals
- central vacuole
Eukaryotic cells differ from prokaryotic cells in all of the following ways EXCEPT that:
- eukaryotic cells from the same organism are identical in their organelle content
- eukaryotic cells have membrane-bound organelles
- eukaryotic cells have very little DNA compared to prokaryotic cells
- eukaryotic cells have a cytoskeleton
- eukaryotic cells are larger
In Figure 04-02, what type of cell is this?
- prokaryotic cell
- stem cell
- red blood cell
- animal cell
- plant cell
Of the objects listed, which is the smallest that you can see without the aid of a microscope?
- frog embryo
- human skin cell
- DNA molecule
Cells require which of the following to form cilia or flagella?
- intermediate filaments
In a plant cell, DNA may be found ____.
- in the nucleus, mitochondria, chloroplasts, and peroxisomes
- in the nucleus, mitochondria, and chloroplasts
- only on the nucleus
- only in the nucleus and chloroplasts
Cell biologists often use the technique of cell fractionation to separate components of cells from each other for better study. In this technique, cells are first disrupted by some means, such as strong agitation or chemical treatment. This breaks the plasma membranes into fragments and releases the organelles. The various organelles and components of the cells can then be separated by a machine called a centrifuge that spins the disrupted cells and separates the components by size and density. Spinning the disrupted cells at low speeds for short periods of time separates the largest components of the sample. Spinning for longer periods at faster speeds separates out increasingly smaller components. The result is a series of separated samples, or fractions, representing collections of similarly sized organelles. In cell fractionation, which of the following organelles would be likely to be separated first?
Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely involved in this disease?
- Golgi apparatus
A mutant plant cell with no chloroplasts would NOT be:
- able to convert carbohydrate to energy
- able to capture energy as sunlight
- A and B
- A, B, and C
The cytoplasm of eukaryotic cells does NOT contain:
- dissolved nutrients
- a nucleoid
An advantage of light microscopy over electron microscopy is that ____.
- light microscopy allows one to view dynamic processes in living cells
- light microscopy provides for higher magnification than electron microscopy
- light microscopy provides for higher resolving power than electron microscopy
- light microscopy provides higher contrast than electron microscopy
Microtubules are responsible for all of the following EXCEPT:
- movement of cilia and flagella
- cell shape
- organization of organelle in the cytoplasm
- movement of chromosomes in eukaryotic cells
- pinching off the of the cytoplasm a eukaryotic cell division
Cell size is limited by ___.
- surface to volume ratios
- the number of proteins within the plasma membrane
- the size of the endomembrane system
- the surface area of mitochondria in the cytoplasm