BIOL 1408 Unit 2 Exam
One centimeter = ________ millimeters. A) 0.10 B) 0.01 C) 100 D) 10
10
The diameter of most animal and plant cells ranges from A) 100 to 1000 micrometers. B) 1.0 to 10 micrometers. C) 0.1 to 1.0 micrometers. D) 10 to 100 micrometers.
10 to 100 micrometers
A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding? A) A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria. B) A defect in the rough endoplasmic reticulum prevented the synthesis of the antibodies (defensive proteins) that would have inactivated the bacteria. C) A defect in the Golgi apparatus prevented the cells from processing and excreting the bacteria. D) A defect in the cell walls of the white blood cells permitted bacteria to enter the cells.
A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
Cyanide inhibits mitochondrial function; as a result, the rate of ______ A) ATP synthesis increases. B) protein synthesis increases. C) photosynthesis increases. D) ATP synthesis decreases.
ATP synthesis decreases
Which of the following statements regarding active transport is false? A) Active transport requires the cell to expend energy. B) Active transport uses ATP as an energy source. C) Active transport is driven by the concentration gradient. D) Active transport can move a solute against its concentration gradient
Active transport is driven by the concentration gradient
Which of the following statements regarding cells is false? A) All cells can interconvert forms of energy. B) All cells have DNA as their genetic material. C) All cells are enclosed in a membrane that maintains internal conditions different from the surroundings. D) All cells have a cell wall.
All cells have a cell wall.
Which of the following statements about cells is true? A) All cells are motile. B) All cells have internal structures that move. C) All cells have cell walls. D) All cells are attached to other cells.
All cells have internal structures that move.
Which of the following statements regarding thermodynamics is false? A) An automobile engine is a closed system because it does not exchange energy and matter with its surroundings. B) Thermodynamics is the study of energy transformations that occur in a collection of matter. C) An open system exchanges both energy and matter with its surroundings. D) A single cell or the planet Earth could be a thermodynamic system.
An automobile engine is a closed system because it does not exchange energy and matter with its surroundings
The process of a white blood cell engulfing a bacterium is A) osmosis. B) phagocytosis. C) pinocytosis. D) receptor-mediated endocytosis
B) phagocytosis.
Which of the following statements about cellular metabolism is false? A) Cellular metabolism often occurs on the surfaces of internal membranes. B) Cellular metabolism includes different processes that require different conditions. C) Cellular metabolism occurs in animal but not plant cells.
Cellular metabolism occurs in animal but not plant cells.
How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor? A) Competitive inhibitors change the enzyme's tertiary structure; noncompetitive inhibitors cause polypeptide subunits to dissociate. B) Competitive inhibitors interfere with the enzyme; noncompetitive inhibitors interfere with the reactants. C) Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site. D) Competitive inhibitors bind to the enzyme reversibly; noncompetitive inhibitors bind to it irreversibly.
Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.
Which of the following statements regarding diffusion is false? A) Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated. B) Diffusion occurs even after equilibrium is reached and no net change is apparent. C) Diffusion is a result of the thermal energy of atoms and molecules. D) Diffusion requires no input of energy into the system.
Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
Which of the following statements about electron microscopes is true? A) Scanning electron microscopes are used to study the details of internal cell structure. B) Transmission electron microscopes are mainly used to study cell surfaces. C) Specimens must be sectioned to be viewed under a scanning electron microscope. D) Electron microscopes focus electron beams to create a magnified image of an object.
Electron microscopes focus electron beams to create a magnified image of an object.
A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action? A) Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions. B) Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in thecell. C) Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. D) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.
Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.
Which of the following statements regarding enzyme function is false? A) Enzymes emerge unchanged from the reactions they catalyze. B) An enzyme's function depends on its three-dimensional shape. C) Enzymes are very specific for certain substrates. D) Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction.
Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction.
Which of the following statements about internal membranes in eukaryotic cells is false? A) In eukaryotic cells, internal membranes form membranous compartments called organelles. B) In eukaryotic cells, internal membranes standardize the internal environment of all cellular organelles. C) In eukaryotic cells, internal membranes greatly increase a cell's total membrane area. D) In eukaryotic cells, internal membranes provide an additional area for many metabolic processes to occur.
In eukaryotic cells, internal membranes standardize the internal environment of all cellular organelles.
Which of the following statements about the ATP molecule is true? A) Extremely stable bonds link the second and third phosphate groups. B) It contains the sugar glucose. C) It contains five phosphate groups. D) It releases energy when one phosphate group leaves ATP.
It releases energy when one phosphate group leaves ATP.
Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do? A) It doesn't matter if the cough drop is in one piece or many pieces; the total amount of cough drop is all that matters. B) Break the cough drop into little pieces and put them all in your mouth. This decreases the surface-to-volume ratio and slows the dissolution of the cough drop. C) Break the cough drop into little pieces and put them all in your mouth. Since each little piece must be dissolved separately, the drop will last longer. D) Keep the cough drop whole. This maintains the largest surface-to-volume ratio and slows the dissolution of the cough drop.
Keep the cough drop whole. This maintains the largest surface-to-volume ratio and slows the dissolution of the cough drop.
Which of the following statements about lysosomes is false? A) Lysosomes synthesize proteins from the recycled amino acids. B) Lysosomes help to digest worn-out or damaged organelles. C) Lysosomes fuse with food vacuoles to expose nutrients to lysosomal enzymes. D) Lysosomes destroy harmful bacteria engulfed by white blood cells.
Lysosomes synthesize proteins from the recycled amino acids
Which of the following statements regarding membrane protein function is false? A) Membrane proteins form junctions between cells. B) Membrane proteins transfer genetic information to the cytoplasm. C) Membrane proteins serve as enzymes. D) Membrane proteins act as receptors to molecules like hormones.
Membrane proteins transfer genetic information to the cytoplasm
White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs). When looking at a sample of blood for WBCs, what could you do to reduce interference from RBCs? A) Mix the blood in a hypertonic solution, which will cause the RBCs to lyse. B) Mix the blood in a hypotonic solution, which will cause the RBCs to lyse. C) Mix the blood in an isotonic solution and allow the WBCs to float to the top. D) Mix the blood in a salty solution to cause the RBCs to lyse
Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer? A) CO2 B) a small, nonpolar molecule such as butane (C4H10) C) O2 D) Na+
Na+
Which of the following statements about the cytoskeleton is false? ______ A) The cytoskeleton is composed of three types of fibers: microfilaments, microtubules, and intermediate filaments. B) The cytoskeleton plays an important role in amoeboid motion. C) Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place. D) The cytoskeleton helps to support cells
Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
Which of the following statements about plant cell walls is false? A) Plant cell walls protect plant cells by forming an impermeable layer around the cell. B) Wood is primarily composed of plant cell walls. C) Plant cell walls consist of cellulose fibers embedded in a matrix of polysaccharides and proteins. D) Plant cell walls are multilayered structures.
Plant cell walls protect plant cells by forming an impermeable layer around the cell.
Which of the following statements regarding plasmodesmata is false? A) Plasmodesmata are found in plants as well as some single-celled organisms. B) Plasmodesmata carry nutrients between plant cells. C) Plasmodesmata penetrate plant cellwalls. D) Plasmodesmata carry chemical messages between plant cell
Plasmodesmata are found in plants as well as some single-celled organisms.
________ cells lack a membrane-enclosed nucleus. A) Prokaryotic B) Fungal C) Eukaryotic D) Plant
Prokaryotic
A group of single cell organisms collected from the ocean was brought into the lab for examination. The lab assistant was concerned that the water had become full of toxic waste products and so added clean water to the culture. All of the organisms died, and when she looked at them under the microscope, all she could see were bits and pieces of them scattered throughout the water. What likely happened? A) She added sea water to which she had added too much salt, and they ruptured. B) She added too little salt to the sea water she added, and the organisms all lost too much water and shriveled up. C) She added water that was hypotonic to the culture of organisms, and they ruptured. D) She added water isotonic to the organisms, causing too much water to move in and out of the organism, and they ruptured.
She added water that was hypotonic to the culture of organisms, and they ruptured.
Which of the following statements regarding the Golgi apparatus is false? A) The Golgi apparatus serves as a molecular warehouse and finishing factory. B) The Golgi apparatus works closely with the endoplasmic reticulum. C) The Golgi apparatus decreases in size when a cell increases its protein production. D) The Golgi apparatus modifies chemicals received from the endoplasmic reticulum.
The Golgi apparatus decreases in size when a cell increases its protein production.
Which of the following statements about the functions of a plant cell central vacuole is false? A) The central vacuole of a plant cell may store waste products. B) The central vacuole of a plant cell may store poisons. C) The central vacuole of a plant cell may help increase the size of cells by absorbing water. D) The central vacuole of a plant cell may digest chemicals for recycling
The central vacuole of a plant cell may digest chemicals for recycling
Which of the following statements is truefor all types of passive transport? A) Proteins are needed to transport molecules across the membrane. B) Ions never cross the plasma membrane by passive transport. C) Only small polar molecules are able to cross the plasma membrane. D) The concentration gradient is the driving force.
The concentration gradient is the driving force.
Which of the following statements regarding the endomembrane system is false? A) The endomembrane system is a system of interrelated membranes that are all physically connected. B) The endomembrane system includes the nuclear envelope. C) The endomembrane system is involved in the synthesis, storage, and export ofimportant molecules. D) The endomembrane system includes the rough and smooth endoplasmic reticulum.
The endomembrane system is a system of interrelated membranes that are all physically connected.
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID)inhibit inflammation by inhibiting an enzyme in the prostaglandin pathway, but by inhibiting this enzyme and this pathway they also inhibit pathways that protect the stomach from damage by stomach acid and that prevent aggregation of blood platelets to form blood clots. What can you conclude from this? A) Prostaglandins cause blood clotting. B) The enzyme is found in many different types of cells. C) Aspirin should not be given to people who people who need to synthesize enzymes. D) The enzyme inhibition is nonreversible.
The enzyme is found in many different types of cells.
Which of the following statements regarding membrane function is false? A) The plasma membrane is the control center of the cell. B) The plasma membrane plays a role in transferring signals to the cell's interior. C) The plasma membrane forms a selective barrier around the cell. D) The plasma membrane has receptors for chemical messages
The plasma membrane plays a role in transferring signals to the cell's interior.
Which of the following is a typical feature of an ATP-driven active transport mechanism? A) The solute moves against the concentration gradient. B) The transport protein catalyzes the conversion of ADP to ATP. C) The transport protein must cross to the correct side of the membrane before the solute can bind to it. D) The transport protein is irreversibly phosphorylated as transport takes place
The solute moves against the concentration gradient
Light microscopes A) work by reflecting electrons off the surface of an object being studied. B) use light and glass lenses to magnify an image. C) typically provide more resolution than an electron microscope. D) are generally not used to view bacteria.
Use light and glass to magnify an image
In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur? A) Water will enter the balloon. B) Sucrose will leave the balloon. C) Sucrose will enter the balloon. D) Water will leave the balloon
Water will leave the balloon
If you were working for a pharmaceutical company as part of a drug discovery team, which of these enzyme inhibitors would you suggest as a productive avenue for drug development? A) a compound that inhibits enzymes by significantly changing the pH throughout the body B) a drug to treat high blood pressure that reversibly inhibits an enzyme catalyzing production of a chemical that causes blood vessels to contract C) a compound that acts as a competitive inhibitor for a digestive enzyme produced only in the presence of certain foods D) a drug to treat diabetes that irreversibly inhibits an enzyme in the metabolic pathway to synthesize glucose
a drug to treat high blood pressure that reversibly inhibits an enzyme catalyzing production of a chemical that causes blood vessels to contract
A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why? A) a scanning electron microscope, because it can reveal structures on cell surfaces B) a light microscope, because it allows observations of whole, live cells C) a scanning electron microscope, because it can be used to observe whole cells without slicing them D) a transmission electron microscope, because it has high resolution
a light microscope, because it allows observations of whole, live cells
A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which of the following instruments would be best? A) a scanning electron microscope B) an inverted light microscope C) a transmission electron microscope D) a fluorescence confocal microscope
a scanning electron microscope
Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell occurs when A) the extracellular matrix is moved to the inside of the cell. B) a protein receptor on the interior of the membrane become bounds by a signaling molecule. C) a signaling molecule binds to a protein that extends to the outside of the cell. D) glycoproteins are recognized by other cells.
a signaling molecule binds to a protein that extends to the outside of the cell.
The endosymbiosis hypothesis proposes that A) a large cell engulfed and digested a smaller cell, exposing its enzymes for use by the larger cell. B) two cells merged into one cell, improving the enzyme function of the new cell. C) two separate cells worked cooperatively and one benefited from the other. D) a small cell lived inside a larger cell to the benefit of both cells.
a small cell lived inside a larger cell to the benefit of both cells.
A man with a dirty cut on his hand appears at the emergency department for treatment. In order to clean the wound, the health-care provider should use A) distilled water. B) a weak (low concentration) solution of salt water. C) a solution of very low pH to help kill any bacteria present. D) a solution of sterilized tap water.
a weak (low concentration) solution of salt water
Which of the following substances could be a cofactor? A) a protein B) a zinc atom C) a polypeptide D) a ribosome
a zinc atom
Resolution is the A) ability of an optical instrument to magnify an image. B) distance between the lenses of a microscope. C) size of an image. D) ability of an optical instrument to show two close objects as separate.
ability of an optical instrument to show two close objects as separate.
The energy required to initiate an exergonic reaction is called A) exergonic energy. B) endergonic energy. C) activation energy. D) input energy.
activation energy
Substrates bind to an enzyme's ________ site. A) inhibitory B) allosteric C) phosphate D) active
active
Which of the following processes can move a solute against its concentration gradient? A) osmosis B) facilitated diffusion C) passive transport D) active transport
active transport
Aquaporins A) allow water to cross the plasma membrane against its concentration gradient. B) allow water to cross the plasma membrane via facilitated diffusion. C) are found in all cells. D) allow forthe active transport of water.
allow water to cross the plasma membrane via facilitated diffusion.
The membranous compartmentalization of a cell A) is common to both prokaryotes and eukaryotes. B) divides the cell into two equal-sized halves. C) requires the presence of a cell wall. D) allows different chemical conditions to be maintained in different parts of the cell.
allows different chemical conditions to be maintained in different parts of the cell.
Skin cells are fastened into strong sheets by A) communicating junctions. B) basal bodies. C) tight junctions. D) anchoring junctions.
anchoring junctions
Which of the following cells has the greatest surface-to-volume ratio? A) human muscle cell B) bacterium C) human red blood cell D) ostrich egg
bacterium
Dynein feet A) are the anchoring proteins in basal bodies. B) are present in cilia but notin flagella. C) are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets. D) are knobs of carbohydrate that are essential to the movement of cilia and flagella.
are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets.
In the plasma membrane, the phospholipid heads A) are hydrophilic and face outward toward the aqueous solution on both sides of the membrane. B) are hydrophobic and face outward toward the aqueous solution on both sides of the membrane. C) are hydrophobic and face inward, shielded from water. D) are hydrophilic and face inward, shielded from water.
are hydrophilic and face outward toward the aqueous solution on both sides of the membrane.
Microfilaments differ from microtubules in that microfilaments ______ A) are found only in plants, whereas microtubules are found in both plant and animal cells. B) help to anchor organelles, whereas microtubules primarily function to help cells change shape and move. C) are thicker than microtubules. D) are mainly composed of actin, whereas microtubules are composed of tubulin
are mainly composed of actin, whereas microtubules are composed of tubulin
You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells A) could be either plant or bacterial cells. B) are plant cells. C) are bacterial cells. D) are animal cells.
are plant cells.
Americans spend up to $100 billion annually for bottled water (41 billion gallons). The only beverages with higher sales are carbonated soft drinks. Recent news stories have highlighted the fact that most bottled water comes from municipal water supplies (the same source as your tap water), although it may undergo an extra purification step called reverse osmosis.Imagine two tanks that are separated by a membrane that's permeable to water, but not to the dissolved minerals present in the water. Tank A contains tap water and tank B contains the purified water. Under normal conditions, the purified water would cross the membrane to dilute the more concentrated tap water solution. In the reverse osmosis process, pressure is applied to the tap water tank to force the water molecules across the membrane into the pure water tank. After the reverse osmosis system has been operating for 30 minutes, the solution in tank A would A) be hypertonic to tank B. B) move by passive transport to tank B. C) be isotonic to tank B. D) be hypotonic to tank B
be hypertonic to tank B.
A plant cell in a hypotonic solution A) shrivels because of an outflow of water. B) becomes turgid because of an inflow of water. C) bursts because of an inflow of water. D) wilts because of an outflow of water.
becomes turgid because of an inflow of water
Which of the following structures is/are used by prokaryotes for attaching to surfaces? A) flagella B) nucleoid C) capsule D) anchoring junctions
capsule
Tay-Sachs disease A) prevents the breakdown of glycogen. B) causes an accumulation of lipids in brain cells. C) is due to the absence of an enzyme that digests polysaccharides. D) involves damage to liver cells.
causes an accumulation of lipids in brain cells.
Which figure depicts an animal cell placed in a solution hypotonic to the cell? A) cell A B) cell B C) cell C D) cell D
cell A
A scanning electron microscope is used to study ________, whereas a transmission electron microscope is used to study ________. A) internal cell structures; cell surfaces B) dead cells; live cells C) cell surfaces; internal cell structures D) live cells; dead cells
cell surfaces; internal cell structures
The idea that all living things are composed of cells and that all cells come from other cells defines A) organelle theory. B) inheritance of acquired characteristics. C) cell theory. D) the laws of inheritance
cell theory
The function of mitochondria is A) lipid synthesis. B) cellular respiration. C) intracellular digestion. D) photosynthesis.
cellular respiration.
Unlike animal cells, plant cells have ________ and ________. Unlike plant cells, animal cells have ________. A) chloroplasts; cell walls; centrioles B) chloroplasts; cell walls; a nucleus C) centrioles; chloroplasts; cell walls D) centrioles; cell walls; large central vacuoles
centrioles; chloroplasts; cell walls
Heating inactivates enzymes by A) changing the enzyme's three-dimensional shape. B) removing phosphate groups from the enzyme. C) breaking the covalent bonds that hold the molecule together. D) causing enzyme molecules to stick together
changing the enzyme's three-dimensional shape.
Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing A) chemical energy intopotential energy. B) kinetic energy into thermal energy. C) kinetic energy into potential energy. D) chemical energy into kinetic energy.
chemical energy into kinetic energy.
The complex of proteins and DNA in a nondividing cell is called A) chromatin. B) a lysosome. C) a nucleolus. D) a ribosome.
chromatin.
During cell reproduction, chromatin fibers coil up into structures called A) chromosomes. B) lysosomes. C) ribosomes. D) nucleoli.
chromosomes
Cilia differ from flagella in that A) cilia contain nine microtubule doublets surrounding a central pair of microtubules, whereas flagella contain only nine microtubule doublets. B) cilia are anchored only in the proteins of the cell membrane, whereas flagella are anchored in a special structure called the basal body. C) cilia are typically more numerous and shorter than flagella. D) the protein filaments of cilia are "naked," whereas those of flagella are wrapped in an extension of the cell membrane.
cilia are typically more numerous and shorter than flagella.
Mitochondria differ from chloroplasts in that mitochondria A) are not found in plants, whereas chloroplasts are not found in animals. B) contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana. C) contain three different membrane-bound compartments, whereas chloroplasts contain two. D) convert light energy from the sun to chemical energy, whereas chloroplasts convert one form of chemical energy to another.
contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana
The nucleus of a cell A) is the primary location of protein synthesis. B) contains DNA. C) is surrounded by a single layer of membrane. D) is contained within the nucleolus
contains DNA.
The nucleoid region of a prokaryotic cell A) contains the cell's nucleoli. B) separates the RNA from the cytoplasm. C) contains the cell's DNA. D) is surrounded by a nucleoid membrane.
contains the cell's DNA
Inhibition of an enzyme is irreversible when A) covalent bonds form between inhibitor and enzyme. B) a noncompetitive inhibitor is involved. C) the shape of the enzyme is changed. D) a competitive inhibitor is involved.
covalent bonds form between inhibitor and enzyme
The ________ of a mitochondrion is/are an adaptation that increases the surface area and enhances a mitochondrion's ability to produce ATP. A) stroma B) cristae C) matrix D) intermembrane space
cristae
Living systems A) are examples of a closed system. B) violate the second law of thermodynamics. C) decrease their entropy while increasing the entropy of the universe. D) violate the first law of thermodynamics.
decrease their entropy while increasing the entropy of the universe
The fluid mosaic model describes the plasma membrane as consisting of A) a phospholipid bilayer with embedded carbohydrates. B) two layers of phospholipids with cholesterol sandwiched between them. C) diverse proteins embedded in a phospholipid bilayer. D) carbohydrates and phospholipids that can drift in the membrane.
diverse proteins embedded in a phospholipid bilayer.
Phagocytosis is to eating as pinocytosis is to A) osmosis. B) chewing. C) lysis. D) drinking.
drinking.
Small, nonpolar, hydrophobic molecules such as fatty acids A) require transport proteins to pass through a membrane's lipid bilayer. B) easily pass through a membrane's lipid bilayer. C) very slowly diffuse through a membrane's lipid bilayer. D) are actively transported across cell membranes.
easily pass through a membrane's lipid bilayer.
Most animal cells are A) embedded in an extracellular matrix. B) embedded in a lipid matrix. C) surrounded by a cell wall. D) attached to each other via plasmodesmata.
embedded in an extracellular matrix.
ATP can be used as the cell's energy exchange mechanism because A) ATP is a disposable form of chemical energy, used once and then discarded by the cell. B) ATP is the most energy-rich small molecule in the cell. C) endergonic reactions can be fueled by coupling them with the formation of ATP from ADP. D) endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP
endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP
An immune system cell called the plasma cell produces thousands of antibodies per second for release into the body. What type of intracellular structure would you expect to be very prominent within the cell? A) endoplasmic reticulum B) microtubules C) peroxisome D) nucleus
endoplasmic reticulum
Which location in the cell is unlikely to contain ribosomes or ribosomal subunits? A) nuclear envelope B) cytoplasm C) plasma membrane D) endoplasmic reticulum
endoplasmic reticulum
When a cell uses chemical energy to perform work, it uses the energy released from a/an ________ reaction to drive a/an ________ reaction. A) spontaneous; exergonic B) exergonic; spontaneous C) endergonic; exergonic D) exergonic; endergonic
exergonic; endergonic
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will A) exhibit a net movement to the side with lower solute concentration. B) exhibit a net movement to the side with higher free water concentration. C) exhibit an equal movement in both directions across the membrane. D) exhibit a net movement to the side with lower free water concentration
exhibit a net movement to the side with lower free water concentration
Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion? A) pinocytosis B) diffusion C) endocytosis D) exocytosis
exocytosis
The cholesterol associated with animal cell membranes A) helps to keep phospholipids from being too close to one another. B) helps solidify the membranes when the room temperature is below freezing. C) is attached to membrane proteins and extends into the watery environment surrounding the cell. D) is an abnormality resulting from a diet high in cholesterol.
helps to keep phospholipids from being too close to one another
Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of A) irreversible inhibition. B) competitive inhibition. C) noncompetitive inhibition. D) feedback inhibition.
feedback inhibition
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are A) anchoring junctions. B) tight junctions. C) gap junctions. D) occluding junctions
gap junctions.
A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they A) have lost water and shrunk. B) have gained water and burst. C) have died because wastes have built up in the cytoplasm. D) have died of malnutrition.
have gained water and burst.
Membrane phospholipids A) have hydrophilic tails that face outward and are exposed to water. B) have hydrophobic heads that face the center of the membrane and are shielded from water. C) are able to drift about in the plasma membrane. D) remain fluid because they are tightly packed against one another.
have hydrophilic tails that face outward and are exposed to wate
Which of the following direct energy transfers is impossible in living systems? A) chemical energy to kinetic energy B) light energy to potential energy C) heat to light energy D) light energy to chemical energy
heat to light energy
In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the balloon is ________ relative to the solution in the beaker. A) isotonic B) hypotonic C) hydrophilic D) hypertonic
hypotonic
The extracellular matrix attached to cells via glycoproteins may then bind to ________ in the plasma membrane. A) integrins B) collagen C) polysaccharides D) dynein
integrins
Which of the following would be most affected by a mutation that prevented cells from forming tight junctions? A) direct flow of water and small molecules from one cell to another B) integrity of the inner lining of the digestive tract C) attachment of cells to the surrounding matrix D) attachment of the cytoskeleton to the inside of the plasma membrane
integrity of the inner lining of the digestive tract
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment A) is isotonic to the protozoan. B) is hypotonic to the protozoan. C) is hypertonic to the protozoan. D) contains a higher concentration of solutes than the protozoan.
is hypotonic to the protozoan
Protein synthesis requires the use of mRNA, which A) must be made by the ribosomes. B) carries the message to the nucleus to synthesize new DNA during cell division. C) is made in the nucleolus. D) is translated by the ribosomes into the amino acid sequences of proteins
is translated by the ribosomes into the amino acid sequences of proteins
A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be A) isotonic to its environment. B) hypotonic to its environment. C) hypertonic to its environment. D) metabolically inactive.
isotonic to its environment
When an enzyme catalyzes a reaction, A) it acts as a reactant. B) it is used once and discarded. C) it raises the activation energy of the reaction. D) it lowers the activation energy of the reaction
it lowers the activation energy of the reaction
Kinetic energy differs from chemical energy in that A) kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into heat. B) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules. C) chemical energy is a particular form of kinetic energy. D) kinetic energy is stored energy that hasthe potential to do work, and chemical energy is the energy of movement.
kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules
The function of chloroplasts is A) photosynthesis. B) cellular respiration. C) intracellular digestion. D) lipid synthesis.
lipid synthesis.
In a hypotonic solution, an animal cell will A) neither gain nor lose water. B) experience turgor. C) lyse. D) shrivel.
lyse
Tay-Sachs disease results from the malfunction of A) lysosomes. B) endoplasmic reticulum. C) nucleoli. D) mitochondria.
lysosomes.
The main function of the rough endoplasmic reticulum is the production of A) hydrogen peroxide and steroid hormones secreted by the cell. B) mitochondria and proteins secreted by the cell. C) ribosomes and steroid hormones. D) membrane and proteins secreted by the cell
membrane and proteins secreted by the cell
According to this figure, which of the following are large enough to see in the light microscope? A) mitochondria B) viruses C) proteins D) atoms
mitochondria
The endosymbiosis hypothesis is supported by all of the following pieces of evidence except the fact that A) mitochondria have circular DNA like prokaryotes. B) chloroplasts have ribosomes like prokaryotes. C) mitochondria lack ribosomes like prokaryotes. D) chloroplasts reproduce through a splitting process like certain prokaryotes.
mitochondria lack ribosomes like prokaryotes.
Many physiological conditions are related to particular proteins in cell membranes. The number of insulin receptors in membranes is related to the amount of insulin present around those cells. If the presence of increased insulin results in a decrease in receptors and a decrease in insulin results in an increase in insulin receptors, this would be an example of A) passive transport. B) a metabolic pathway. C) negative or regulatory feedback. D) competitive inhibition.
negative or regulatory feedback.
Which of the following structures is exclusively associated with prokaryotic cells? A) chromosome B) membrane-bound nucleus C) ribosomes D) nucleoid
nucleoid
A bacterial cell's DNA is found in its A) nucleoid region. B) ribosomes. C) nucleus. D) capsule
nucleoid region.
Secretory proteins are A) produced by the cell for internal use. B) released from the cell through the plasma membrane. C) produced by ribosomes on the smooth endoplasmic reticulum. D) chemically modified in the nucleus.
released from the cell through the plasma membrane.
Which part of the ATP molecule breaks free of the rest when an ATP molecule is used for energy? A) part A B) part B C) part C D) part D
part D
Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of A) passive transport. B) active transport. C) endocytosis. D) exocytosis.
passive transport
Oxygen crosses a plasma membrane by A) passive transport. B) pinocytosis. C) active transport. D) osmosis.
passive transport.
The endomembrane system includes all of the following organelles except the A) peroxisome. B) Golgi apparatus. C) endoplasmic reticulum. D) plasma membrane.
peroxisome
Which organelle is involved in the catabolism of fatty acids and the detoxification of alcohol? A) Golgi apparatus B) ribosomes C) smooth ER D) peroxisome
peroxisome
Which of the following cell structures are associated with the breakdown of harmful substances? A) chloroplasts B) peroxisomes C) centrioles D) mitochondria
peroxisomes
The transfer of a phosphate group to a molecule or compound is called A) hydrogenation. B) phosphorylation. C) ionization. D) carboxylation.
phosphorylation
Contractile vacuoles A) prevent cells from bursting as a result of the influx of excess water. B) are generally found in protists that inhabit salt water. C) help in the excretion of excess salt. D) allow organisms to avoid dehydration by absorbing water from the environment.
prevent cells from bursting as a result of the influx of excess water.
A woman is having trouble becoming pregnant. Examination of her partner's sperm indicates that dynein feet are missing from the flagella in his sperm cells. A physician explains that this could interfere with fertility by A) interfering with the attachment of the flagella to the sperm. B) preventing the sperm from producing enough energy to power swimming. C) preventing the sperm from swimming to the egg cell. D) preventing the sperm from attaching to the egg cell.
preventing the sperm from swimming to the egg cell.
An energy barrier A) is the amount of energy that must be produced by the reactants to end a chemical reaction. B) can only be overcome with the use of enzymes. C) is higher than the activation energyof a reaction. D) prevents the spontaneous breakdown of molecules in the cell
prevents the spontaneous breakdown of molecules in the cell
Archaea are composed of ________ cells. A) prokaryotic B) eukaryotic C) bacterial D) anima
prokaryotic
Most of a cell's enzymes are A) proteins. B) lipids. C) amino acids. D) carbohydrates.
proteins
The molecules responsible for membrane transport are A) carbohydrates. B) steroids. C) phospholipids. D) proteins
proteins
Most of the functions of a cell membrane, including transport and enzymatic function, are performed by A) glycolipids. B) cholesterol. C) phospholipids. D) proteins.
proteins.
Cells acquire low-density lipoproteins (LDLs) by A) receptor-mediated endocytosis. B) diffusion. C) pinocytosis. D) phagocytosis.
receptor-mediated endocytosis
Anything that prevents ATP formation will most likely A) force the cell to rely on lipids for energy. B) force the cell to rely on ADP for energy. C) have no effect on the cell. D) result in cell death
result in cell death
The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The protein melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function Based on their function, you would expect melanocytes in the skin to have a higher than usual number of A) ribosomes. B) chloroplasts. C) microtubules. D) lysosomes
ribosomes
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following options correctly lists the order of the structures through which insulin passes from its production to its exit from the cell? A) rough ER, lysosomes, transport vesicles, cell membrane B) rough ER, transport vesicles, Golgi apparatus, vacuole, cell membrane C) rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane D) rough ER, Golgi apparatus, smooth ER, cell membrane
rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane
The cells that produce hair made of protein contain a lot of ________, while the cells that produce the oils that coat the hair contain a lot of ________. A) microbodies; lysosomes B) smooth endoplasmic reticulum; rough endoplasmic reticulum C) smooth endoplasmic reticulum; lysosomes D) rough endoplasmic reticulum; smooth endoplasmic reticulum
rough endoplasmic reticulum; smooth endoplasmic reticulum
Which characteristic promoted the utilization of lipids as the first cell membrane? A) formation of a semi-solid membrane B) spontaneous degradation of the intracellular environment C) self-assembly into a simple membrane D) ability to form an impermeable membrane
self-assembly into a simple membrane
A basal body is A) identical in structure to cilia. B) similar in structure to centrioles. C) composed of nine microtubule doublets surrounding a central pair of microtubules. D) composed of nine microtubule triplets surrounding a central pair of microtubules.
similar in structure to centrioles.
Osmosis can be defined as A) the diffusion of a solute. B) the diffusion of nonpolar molecules. C) active transport. D) the diffusion of water.
the diffusion of water.
The oil from the sebaceous glands is produced by which of the following cell organelles? A) cell membrane B) ribosomes C) rough endoplasmic reticulum D) smooth endoplasmic reticulum
smooth endoplasmic reticulum
Smooth endoplasmic reticulum A) produces proteins for cell membranes. B) helps assemble ribosomes for protein synthesis. C) is the major site of carbohydrate synthesis in eukaryotic cells. D) stores calcium ions in muscle cells
stores calcium ions in muscle cells
The Golgi apparatus A) stores, modifies, and packages proteins. B) is composed of stacks of membranous vesicles that are continuous with one another. C) strings together amino acids to produce proteins. D) is the site of carbohydrate breakdown.
stores, modifies, and packages proteins.
Which part of the mitochondrion shown enhances its ability to produce ATP by increasing the surface area of a mitochondrial membrane? A) structure A B) structure B C) structure C D) structure D
structure D
According to ________, energy cannot be created or destroyed. A) the second law of thermodynamics B) the third law of thermodynamics C) the first law of thermodynamics D) Aristotle's first principle
the first law of thermodynamics
All cells are enclosed by a plasma membrane that is similar in ________ and ________. A) permeability; content B) lucidity; texture C) structure; function D) thickness; composition
structure; function
Intermediate filaments A) guide the movements of chromosomes. B) guide the movements of organelles. C) support the inner mitochondrial membrane. D) surround the nucleus.
surround the nucleus.
A drug that interferes with microtubule formation is likely to completely disrupt A) the function of lysosomes. B) the movements of sperm cells. C) contraction of muscle cells. D) the amoeboid motion of a cell.
the movements of sperm cells.
Plasma membranes are selectively permeable. This means that A) plasma membranes must be very thick. B) the plasma membrane allows some substances to enter or leave a cell more easily than others. C) glucose cannot enter the cell. D) anything can pass into or out of a cell as longas the membrane is intact and the cell is healthy.
the plasma membrane allows some substances to enter or leave a cell more easily than others
In the reaction A →B + C + heat, A) there is a net input of energy. B) the potential energy of the products is less than that of the reactant. C) entropy has decreased. D) the potential energy of the products is greater than that of the reactant.
the potential energy of the products is less than that of the reactant
The active site of an enzyme is A) the region of an enzyme that attaches to a substrate. B) the region of a substrate that is changed by an enzyme. C) the region of a product that detaches from the enzyme. D) the highly changeable portion of an enzyme that adapts to fit the substrates of various reactions.
the region of an enzyme that attaches to a substrate.
If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference? A) the relative inelasticity and strength of the plant cell wall B) the expulsion of water by the plant cell's central vacuole C) the fact that plant cells are isotonic to tap water D) the relative impermeability of the plant cell wall to water
the relative inelasticity and strength of the plant cell wall
A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates A) the second law of thermodynamics. B) the first law of thermodynamics. C) that some energy is destroyed in every energy conversion. D) that energy transformations are typically 100% efficient.
the second law of thermodynamics
Which of the following processes is endergonic? A) cellular respiration B) the synthesis of glucose from carbon dioxide and water C) the breakdown of glucose D) the burning of wood
the synthesis of glucose from carbon dioxide and water
If you shut off the system and pressure was no longer applied to tank A, you would expect A) the water to flow in equal amounts in both directions. B) the water to flow from tank A to tank B. C) the water to flow against the concentration gradient. D) the water to reverse flow from tank B to tank A.
the water to reverse flow from tank B to tank A.
The stroma is the A) thick fluid enclosed by the inner chloroplast membrane. B) space between the inner and outer membranes of a mitochondrion. C) watery fluid enclosed by the inner membrane of a mitochondrion. D) space between the inner and outer membranes of a chloroplast
thick fluid enclosed by the inner chloroplast membrane.
The function of the nucleolus is A) to manufacture ribosomal RNA. B) to store chromatin. C) intracellular digestion. D) to manufacture polypeptides.
to manufacture ribosomal RNA.
A pathologist who wants to examine a patient's liver cells to determine if the mitochondria have an internal structural defect will likely need to use a A) light microscope. B) scanning electron microscope. C) chromatin stain. D) transmission electron microscope
transmission electron microscope
Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient. A) energy and transport proteins; against B) energy andtransport proteins; down C) transport proteins; down D) transport proteins; against
transport proteins; down
When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will A) undergo self-digestion and die. B) recycle damaged organelles. C) undergo cell division. D) produce replacement lysosomes
undergo self-digestion and die.
Which of the following is a coenzyme? A) iodine B) zinc C)vitamin B6 D) iron
vitamin B6
As cell size increases, the A) ratio of surface area to volume stays the same. B) volume increases proportionally more than the surface area. C) surface area increases proportionally more than the volume. D) volume and surface area decrease.
volume increases proportionally more than the surface area
A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation A) will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs. B) should present no problem to the cell, since it can continue to perform all other necessary functions. C) should be beneficial, since the cell will be able to divert the ATP normally used for cell division to other processes. D) should present no problem to the cell, because the surface area of the cell will increase as the volume of the cell increases
will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs
You are adrift in the Atlantic Ocean and, being thirsty, drink the surrounding seawater. As a result, A) you quench your thirst. B) your cells become turgid. C) your cells lyse from excessive water intake. D) you dehydrate yourself.
you dehydrate yourself.