Biology - Chapter 3

In this figure of a membrane, label the phospholipids, cholesterol, carbohydrate chains, and the four different types of transmembrane proteins (enzymatic, receptor, recognition, and transport proteins), describing a function of each of these components.

(See the figure below.)

How are simple diffusion and facilitated diffusion similar? How are they different? How are facilitated diffusion and active transport similar? How are they different?

Both simple diffusion and facilitated diffusion can only move specific molecules down their concentration gradient, and both do so without an input of energy. In facilitated diffusion, a transport protein assists in this movement, whereas no protein is required for simple diffusion. Both facilitated diffusion and active transport use transport proteins to move specific molecules across a membrane. However, active transport requires an input of energy and can move molecules up their concentration gradient.

Describe the multiple lines of evidence that indicate that both mitochondria and chloroplasts arose through endosymbiosis, in which bacteria came to live inside other cells and ultimately became a part of a more complex eukaryotic organism.

Chloroplasts and mitochondria are similar in size to prokaryotic cells. They also have small amounts of circular DNA that is similar to the circular DNA of prokaryotes and different from the linear DNA of eukaryotes. They also divide by fission, just like prokaryotes. In addition, chloroplasts and mitochondria possess their own ribosomes, which are similar to prokaryotic ribosomes and different from eukaryotic ribosomes.

What is active transport and how and when does it function? What is endocytosis and what is exocytosis? How do they work?

First, the student should define active transport as the movement of atoms, ions, or molecules up the concentration gradient, or from low concentration to high concentration, involving the use of energy in the form of ATP. The answer should also contain the fact that this process requires the use of a transport protein in order to move the substances against the concentration gradient and give an example of when this might occur. In answer to the second part of the question, the student should not only define the terms as movement of bulk substances into or out of the cell, but should also explain the difference between pinocytosis (cellular "drinking"), phagocytosis (cellular "eating"), and receptor-mediated endocytosis.

Detail the differences between a prokaryotic and a eukaryotic cell.

In answer to this question, the student could be very general, noting that a prokaryotic cell lacks membrane-bound organelles while a eukaryotic cell has them. In a more complete answer to the question, the student should compare and contrast the structures present in each type of cell and give a description of each. The instructor could, if this comparison is required, present a table for the student to fill in with the details about each prokaryotic and eukaryotic structure.

The cell can be compared to a factory. Explain which organelles match the following parts of a factory and why they match: the boss, the power plant, the manufacturing floor, the packing department, the storage area, the factory building itself (walls), and the recycling center.

In answer to this question, the student should be able to think about what these areas of a factory do for the factory and compare them to what the various organelles do for the cell. The comparisons to be made are: the boss to DNA or nucleus; the power plant to mitochondrion, the manufacturing floor to the endoplasmic reticulum, the packing department to the Golgi apparatus, the storage area to vesicles or vacuoles, the factory building walls to the cell membrane, and the recycling center to lysosomes. The answer should include what each does for its respective structure, factory, or cell.

Define passive transport and explain what type of passive transport would be used to move each of the following substances into a cell: oxygen, amino acid, and water.

In answer to this question, the student should first note that all passive transport into or out of cells involves the movement of molecules, atoms, or ions down a concentration gradient, or from an area of higher concentration toward an area of lower concentration, without an input of energy to cause the movement. Each of the substances listed would move by a different passive transport means and the correct answer would explain simple diffusion of oxygen, facilitated diffusion of an amino acid, and osmosis of water through the cell membrane. In addition, the student might include the concept of tonicity when describing osmosis and explain the differences among hypertonic, isotonic, and hypotonic solutions in relation to the cell.

Given your understanding of drug detoxification within cells, describe how people who habitually use a particular drug can develop a tolerance to the drug.

Many drugs are detoxified by the smooth endoplasmic reticulum of liver cells. Chronic exposure to a drug can induce a proliferation of smooth ER, which leads to more efficient detoxification of this drug. As a result of this tolerance, higher and higher doses of the drug will be required to obtain the same effect.

Describe the actions of the various components of the endomembrane system in the production, modification, and transport of proteins.

Proteins are assembled by ribosomes attached to the surface of the rough endoplasmic reticulum (ER), and are folded and packaged within the rough ER. Transport vesicles containing these proteins bud from the rough ER, and are transported to the Golgi apparatus, where they are slightly modified and tagged. After these proteins are processed, vesicles containing the proteins bud from the Golgi apparatus and are transported to the location specified by the "tag."

Why does a red blood cell burst when placed in a hypotonic solution such as distilled water, while a plant cell can survive in this environment?

Since there is a higher concentration of water outside of the cells than inside the cells, there is an overall flow of water into the cells, which causes the red blood cell to swell and burst. However, although the plant cell swells slightly, the cell wall outside of the plasma membrane prevents the cell from swelling enough to burst.

Explain the functions of the phospholipid bilayer and the four primary membrane proteins embedded within it.

The answer to this question should not only contain the statement that the purpose of the plasma membrane's phospholipid bilayer is to selectively reject or accept substances into the cell, but also should include a brief description of just what the molecules of the bilayer look like and how they function. Next, the answer should explain that embedded within the plasma membrane are both transmembrane and surface proteins that function in four basic ways for the cell. These four types of membrane proteins are the receptor, transport, recognition, and enzymatic proteins, and the answer should include a description and perhaps an example of what each does.

Mitochondria have two membranes, an inner membrane and an outer membrane. Given your knowledge of phagocytosis and your understanding of the endosymbiotic origin of mitochondria, describe the origins of these two membranes.

The inner membrane is a bacterial membrane, and was possessed by the engulfed bacterium that became the mitochondrion. The outer membrane is derived from the "host" cell that engulfed this bacterium through phagocytosis.

Compare and contrast the theories of endosymbiosis and invagination and the supporting evidence for each.

The student should first explain the concept of the endosymbiotic theory. The answer should then contain information about how the connection between the two or more cells came about and how and why this may have led to at least two different cellular organelles—the chloroplast and the mitochondrion. Next, the student should define invagination and explain how this process could have led to the presence of organelles within a eukaryotic cell.

The lysosomes in a human cell contain approximately ________ type(s) of digestive enzymes. • 1 • 500 • 10 • 4 • 50

• 50

The lipids within the fluid mosaic of the plasma membranes are held in place by: • covalent bonds. • hydrophobic interactions. • hydrogen bonds. • disulfide bridges. • ionic bonds.

• hydrophobic interactions.

What are the two distinct "faces" of the phospholipids that make up the surface membrane of a cell? • a hydrophilic head and a hydrophobic tail • a hydrophobic head and a hydrophilic tail • a phosphate group head and two fatty acid tails • Both a) and c) are correct. • Both b) and c) are correct.

• Both a) and c) are correct.

Which of the following is an important difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum? • The rough endoplasmic reticulum is the site of much protein folding and packaging, while the smooth endoplasmic reticulum is the site of lipid synthesis. • The rough endoplasmic reticulum is studded with chloroplasts, while the smooth endoplasmic reticulum is not. • The rough endoplasmic reticulum is covered in ribosomes while the smooth endoplasmic reticulum is not. • The smooth endoplasmic reticulum is the site of protein synthesis, folding, and packaging, while the rough endoplasmic reticulum is the site of lipid synthesis. • Both a) and c) are correct.

• Both a) and c) are correct.

How are lysosomes distributed among different types of eukaryotic cells? • Every different cell type has the same uniform number of lysosomes. • The functions of lysosomes do not vary depending on cell type. • Cells that process a lot of larger nutrients, such as liver cells, have larger amounts of lysosomes then other cells. • Cells, such as white blood cells, do not need lysosomes because they engulf bacteria on their own. • Both a) and b) are correct.

• Cells that process a lot of larger nutrients, such as liver cells, have larger amounts of lysosomes then other cells.

The rough endoplasmic reticulum is the site of protein synthesis and the smooth endoplasmic reticulum is the site of lipid synthesis. What is the third compartment of the endomembrane system and what is that compartment's function? • Golgi apparatus; finishes the processing of the proteins and sorts them for export out of the cell • Lysosomes; sacs which export the proteins and lipids out of the cell • Ribosomes; the place of protein transcription • Vesicles; packages of proteins surrounded by cell membranes that sort the proteins and lipids for packaging • None of the above is correct.

• Golgi apparatus; finishes the processing of the proteins and sorts them for export out of the cell

In the figure, the round, knobby structures are _______________ and the Y-shaped post-like structures with semicircular receptors are ________________. • beta-blocker chemicals; beta receptors • adrenaline molecules; beta receptors • HIV particles; liver cell molecular fingerprints • HIV particles; CD4 markers • beta-blocker chemicals; adrenaline molecules

• HIV particles; CD4 markers

What makes the rough endoplasmic reticulum rough? • It has a high density of receptor proteins in its membrane. • It is covered with ribosomes. • It is covered with tiny flagella. • Its surface is highly folded to increase surface area. • It is covered with cilia.

• It is covered with ribosomes.

Which of the following statements about the cytoskeleton is FALSE? • It is responsible for some cellular movement. • It is a three-dimensional structure that fills the cytoplasm. • It is made from proteins that act as a scaffolding. • It is present in both prokaryotic and eukaryotic cells. • All of the above are false.

• It is present in both prokaryotic and eukaryotic cells.

What is the main function of the nucleolus? • It is the site of ribosome-subunit synthesis. • It produces cell adhesion proteins that are then exported to the cell membrane. • It is the site of photosynthesis in photosynthetic cells. • It produces enzymes that are then exported to the lysosomes. • Its function is not yet known.

• It is the site of ribosome-subunit synthesis.

Mitochondria are thought to have evolved from free-living bacteria that were incorporated into eukaryotic cells by endosymbiosis. Which of the following pieces of evidence for this hypothesis is INCORRECT? • Mitochondria are enclosed by two membranes rather than a single membrane. • Mitochondrial DNA is packaged as a single circular chromosome, like that of a bacterium. • The phospholipid composition of the inner mitochondrial membrane is similar to that of the bacterial cell membrane. • Mitochondria can survive and reproduce independently when removed from the host cell. • New mitochondria are formed by binary fission rather than being replicated during the cell cycle.

• Mitochondria can survive and reproduce independently when removed from the host cell.

Which of the following facts supports the claim that mitochondria developed from bacteria that were long ago phagocytosed into eukaryotic cells? • Mitochondria have proteins for the synthesis of ATP. • Mitochondria have their own DNA. • Mitochondria are the "powerhouses" of the cell. • Mitochondria have flagella for motion. • Mitochondria are small and easily transported across the membrane.

• Mitochondria have their own DNA.

Which of the following BEST summarizes the differences between osmosis and diffusion? • Diffusion deals only with water. • Osmosis deals only with water. • Diffusion deals only with alkaline liquids. • Osmosis deals only with alkaline liquids. • Osmosis deals only with acidic liquids.

• Osmosis deals only with water.

The malarial Plasmodium and its relatives, the apicomplexans, are not capable of photosynthesis, yet they have a distinctive organelle—the apicoplast—that has four membranes and contains DNA closely related to the DNA found in chloroplasts. The presence of the apicoplast in the apicomplexans supports which of the following hypotheses? • The apicomplexans are closely related to cyanobacteria. • The apicomplexans are closely related to land plants. • The apicomplexans were once capable of photosynthesis. • The apicoplast arose via endosymbiosis. • The apicoplast has no function.

• The apicoplast arose via endosymbiosis.

Which of the following is NOT a way in which the cell's surface membrane interacts with the exterior environment? • The cellular surface mediates attachments to other cells. • The cellular surface receives and transmits incoming messages. • The cellular surface mediates interactions with extracellular material. • The cellular surface controls which substances enter and leave the cell. • The cellular surface organizes the interior organelle organization of the cell.

• The cellular surface organizes the interior organelle organization of the cell.

Which statement is NOT part of modern cell theory? • All living organisms consist of one or more cells. • The first cell arrived on earth from outer space. • Cellular reactions include both energy-releasing and biosynthetic types. • Cells contain hereditary information that passes from one generation of cells to the next. • Cells arise from other cells.

• The first cell arrived on earth from outer space.

A unique characteristic of mitochondria is that they are inherited from the female parent only. Select the correct explanation for this phenomenon from the choices below. • Mitochondria are found in both the female's egg cells and the male's sperm cells, but the sperm exhaust their mitochondria during their swim up the female's fallopian tubes and are not viable upon fertilization. • Mitochondria are found in both the female's egg cells and the male's sperm cells, but after fertilization, the female's mitochondria outcompete the male's mitochondria, which then die off. • The male's sperm cells have mitochondria, but because the sperm contributes DNA but no cytoplasm, no mitochondria are passed to the egg at fertilization. • Mitochondria are only found in the female's egg cells and do not occur in the male's sperm cells. • Mitochondria are found in both the female's egg cells and the male's sperm cells, but the mitochondria from the male's sperm cells cannot replicate during the early mitotic divisions in the embryo.

• Themale's sperm cells have mitochondria, but because the sperm contributes DNA but no cytoplasm, no mitochondria are passed to the egg at fertilization.

Which of the following is NOT true of ALL cells? • They eliminate wastes. • They assimilate nutrients. • They move by means of flagella or cilia. • They have DNA as their genetic material. • They synthesize new cellular material.

• They move by means of flagella or cilia.

______________ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells. • Vesicles • Ribosomes • Peroxisomes • Vacuoles • Lysosomes

• Vesicles

Which of the following is a correct description of how exocytosis functions in transporting molecules across the cellular membrane? • Vesicles are filled with molecules in the interior of the cell and then fuse with the membrane to deposit the molecules outside of the cell. • A receptor protein on the outside of the cell binds to a particular biochemical, causing the membrane to form an indentation and bring the biochemical into the cell. • Protein molecules on the interior of the cellular membrane trap molecules attached on the exterior side and bring them into the cell. • Nutrients are moved within the cell from one tightly woven network to another. • None of the above is correct.

• Vesicles are filled with molecules in the interior of the cell and then fuse with the membrane to deposit the molecules outside of the cell.

Membrane-bound vesicles containing a substance synthesized by a cell fuse to the outer cell membrane and release their contents to the outside world. What is this process called? • exocytosis • pinocytosis • endocytosis • excretocytosis • phagocytosis

• exocytosis

Secretion of cell products like milk proteins and mucus from glandular cells is accomplished via: • exocytosis. • facilitated diffusion. • active transport. • passive transport. • endocytosis.

• exocytosis.

Seventy to 90 percent of the genetic material in a gamete made in your body could be inherited from your mother. How could this be? • You receive many mitochondria, which have their own genome, from your mother, but not from your father. • Your maternal genes kill off your paternal genes at a greater rate than your paternal genes kill off your maternal genes. • The X chromosome is substantially larger than the Y chromosome. • You receive maternal genes through the placenta and through breast milk. • The above statement is incorrect. Fifty percent of the genetic material in your gametes comes from your father.

• You receive many mitochondria, which have their own genome, from your mother, but not from your father.

Which of the following is a cellular characteristic of ALL eukaryotes? • a nuclear membrane • few to no organelles in the cytoplasm • a cell wall • a nucleoid • few to no proteins associated with the DNA

• a nuclear membrane

Eukaryotic cells may contain all of the following EXCEPT: • a membrane-bound nucleus. • a peptidoglycan cell wall. • flagella. • photosynthetic pigments. • ribosomes.

• a peptidoglycan cell wall.

You measure the concentration of a polar molecule inside and outside of a cell. You find that the concentration is high and gradually increasing inside the cell. You also measure the ATP concentration inside the cell and find that it is dropping. What would be your best hypothesis for the process that is occurring? • facilitated diffusion • active transport • endocytosis • passive transport • simple diffusion

• active transport

The movement of H+ ions into the stomach represented in this figure is accomplished through: • osmosis. • simple diffusion. • endocytosis. • active transport. • facilitated diffusion.

• active transport.

The primary function of molecular membranes is the transport of ions and molecules in and out of cells. The movement of molecules from areas of low concentration to those of high concentration against chemical gradients is best described as: • channel-mediated diffusion. • passive transport. • active transport. • electron transport. • inactivated transport.

• active transport.

The figure shows the action of beta-blockers in reducing anxiety. In this diagram, the triangular wedges represent ________________, the figures with rectangular tops and triangular bottoms represent ______________, and the ovals represent ______________. • beta-blocker chemicals; adrenaline; beta-receptors • adrenaline; beta-blocker chemicals; beta-receptors • adrenaline; beta-receptors; beta-blocker chemicals • beta-blocker chemicals; mucus; beta-receptors • mucus; beta-blocker chemicals; beta-receptors

• adrenaline; beta-blocker chemicals; beta-receptors

If the concentrations of a particular molecule are equal on both sides of the membrane, facilitated diffusion will: • insure that the molecule becomes concentrated outside the cell. • insure that the molecule stays impermeable to the membrane. • insure that the molecule becomes concentrated inside the cell. • insure that the concentrations inside and outside the cell are both increased. • be ineffective.

• be ineffective.

Beta-blockers do all of the following EXCEPT: • block signaling through adrenaline receptors. • reduce outward symptoms of anxiety. • bind to the cytoplasmic side of a receptor protein. • reduce high blood pressure. • reduce the effects of adrenaline on the heart.

• bind to the cytoplasmic side of a receptor protein.

Vesicles: • fuse with the nucleus membrane to deliver important enzymes, such as polymerase. • bud off from the endoplasmic reticulum. • deposit their protein cargo in an arbitrary fashion throughout the cell. • return to the Golgi apparatus after they have delivered their proteins to be reused. • Both b) and d) are correct.

• bud off from the endoplasmic reticulum.

Which of the following is NOT an important structural feature on the surface membrane of an animal cell? • lipid bilayer • cholesterol • cell wall • glycoproteins • sugar molecules

• cell wall

Which of the following is the outermost feature on the surface of a plant cell? • lipid bilayer • cholesterol • cell wall • glycoproteins • sugar molecules

• cell wall

Interacting systems of molecules enclosed in compartments called __________ evolved 3.8 billion years ago in living organisms. • brains • organs • circulatory systems • mitochondria • cells

• cells

Which one of the following organelles is NOT found in both plant and animal cells? • mitochondrion • nucleus • smooth endoplasmic reticulum • central vacuole • peroxisome

• central vacuole

Active transport, the moving of molecules from areas of low concentration to those of high concentration across the membrane, is usually coupled to processes that: • counteract osmotic stress. • establish a dynamic equilibrium with no net gain or loss in energy for the cell. • gain energy for the cell. • amplify cellular response to signal molecules. • cost energy.

• cost energy.

The cell connections represented in the figure are: • lysosomes. • tight junctions. • plasmodesmata. • gap junctions. • desmosomes.

• desmosomes.

The net movement of molecules from locally concentrated regions to uniform distributions is best described as: • active transport. • passive transport. • diffusion. • enthalpy. • concentration gradient.

• diffusion.

In aquatic environments, water moves _____________. • down the water-concentration scale • against the water-concentration gradient • up the water-concentration scale • down the water-concentration gradient • up the water-concentration gradient

• down the water-concentration gradient

To absorb large particles, cells engulf them within their plasma membrane in a process called: • replication. • exocytosis. • endocytosis. • transcription. • translation.

• endocytosis.

Where are cell membrane components synthesized? • endoplasmic reticulum • lysosomes • Golgi apparatus • vesicles • nucleus

• endoplasmic reticulum

Phospholipids assemble spontaneously into bilayers driven by the attraction of their "tail" portions to each other and of their "head" portions to each other. The tail regions are: • cohesive. • adhesive. • hydrophilic. • hydrophobic. • molecularly charged.

• hydrophobic.

You are bored at a lunch meeting and surreptitiously place a raisin in your glass of water. The raisin swells to twice its original size. Relative to the water, the raisin must have been: • hypertonic. • isotonic. • hypotonic. • mesotonic. • osmotic.

• hypertonic.

If the solution surrounding a cell contains less solute than the cytoplasm does, the osmotic condition is said to be: • hypotonic. • adiabatic. • isobaric. • hypertonic. • isotonic.

• hypotonic.

The object depicted in the figure: • is a bacterial cell. • could be either a plant or an animal cell. • is a plant cell. • is an animal cell. • is a ribosome.

• is an animal cell.

Which of the following organelles is responsible for degrading waste within the cell? • lysosome • ribosome • chloroplast • endoplasmic reticulum • Golgi apparatus

• lysosome

Which of the following cellular components contains hydrolytic enzymes associated with the digestion of macromolecules? • peroxisomes • lysosomes • centrioles • ribosomes • None of the above is correct.

• lysosomes

Which of the following organelles are enclosed by a double membrane? • vacuoles and the endoplasmic reticulum • ribosomes and lysosomes • mitochondria and chloroplasts • the nucleus and the Golgi apparatus • All organelles are enclosed by a double membrane.

• mitochondria and chloroplasts

Osmosis is _________ specialized than diffusion because it involves _________. • more; water • more; acids • less; acids • less; all liquids • more; bases

• more; water

Which of the following BEST defines diffusion? • net movement of particles between cells • net movement of fluids from the environment into and out of an organism • net movement of particles from a cell into the extracellular matrix • net movement of particles from areas of low concentration to areas of high concentration • net movement of particles from areas of high concentration to areas of low concentration

• net movement of particles from areas of high concentration to areas of low concentration

Which of the following CANNOT occur? • you and your full-sibling sister having identical mitochondrial DNA • two cousins having identical mitochondrial DNA • you and your full-sibling brother having different nuclear DNA • you and your great-grandmother having identical mitochondrial DNA • none of the above; all of these are possible

• none of the above; all of these are possible

The largest structure in a eukaryotic cell is the ____________ and it is surrounded by ______ membranes. • mitochondrion; two • nucleus; one • mitochondrion; one • Golgi apparatus; one • nucleus; two

• nucleus; two

Prokaryotic organisms lack: • replicator molecules (DNA or RNA). • cell membranes. • metabolism. • organelles. • All of the above.

• organelles.

The passive transport of water across a membrane from a solution of lower-solute concentration to a solution of higher-solute concentration is best described as: • active transport. • general diffusion. • osmosis. • passive transport. • facilitated diffusion.

• osmosis.

The primary function of molecular membranes is the transport of ions and molecules in and out of cells—transport is directional and selective. The moving of molecules from areas of high concentration to those of low concentration to gain energy is best described as: • channel-mediated diffusion. • electron transport. • active transport. • inactivated transport. • passive transport.

• passive transport.

Which of the following is NOT a function of the plant vacuole? • photosynthesis • predator deterrence • physical support • waste management • nutrient storage

• photosynthesis

The organelle in the figure is found in: • animals only. • plants only. • plants, animals, and bacteria. • plants and animals. • bacteria only.

• plants and animals.

Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? • nucleolus • nucleus • plasma membrane • cell wall • endoplasmic reticulum

• plasma membrane

Plants have cell walls to give them more structural strength. In order to facilitate movement of molecules from one plant cell to another, there are channels called ___________________ that run through the cell walls. • transport vesicles • desmosomes • plasma membranes • plasmodesmata • vacuoles

• plasmodesmata

Which of the following cell membrane components are present in plant cells but absent in animal cells? • phospholipids • gap junctions • plasmodesmata • proteins • carbohydrates

• plasmodesmata

Nuclear ______ are specialized holes in the ________- layer nuclear envelope that separates the nucleus from the ___________. • pores; one; endoplasmic reticulum • passageways; one; cytoplasm • pores; two; cytoplasm • vesicles; three; endoplasmic reticulum • vesicles; two; cytoplasm

• pores; two; cytoplasm

Mammalian cells take in many molecules, including hormones, antibodies, and blood proteins. This process is coordinated by proteins that recognize their specific target molecule. This process is best described as: • phagocytosis. • active transport. • exocytosis. • receptor-mediated endocytosis. • pinocytosis.

• receptor-mediated endocytosis.

Which of the following is found in both prokaryotic and eukaryotic cells? • Golgi apparatus • ribosome • centriole • lysosome • peroxisome

• ribosome

Given that a cell's structure reflects its function, what would you predict that the function of a cell with a large Golgi apparatus would be? • secretion of digestive enzymes • transport of chemical signals • movement • rapid replication of genetic material and coordination of cell division • attachment to bone tissue

• secretion of digestive enzymes

What is the most important barrier protecting the inner contents of an animal cell from its exterior environment? • the cellular membrane • the cell wall • the nucleus • the cytoskeleton • Both a) and b) are correct.

• the cellular membrane

According to the theory of endosymbiosis, the origin of chloroplasts probably involved: • the formation of cell walls around the photosynthetic pigments. • the formation of colonies of cyanobacteria. • the engulfing of small photosynthetic prokaryotes by larger cells. • the accumulation of free oxygen in ocean waters. • All of the above are correct.

• the engulfing of small photosynthetic prokaryotes by larger cells.

Although cells tend to be spherical, several factors influence cells to assume other shapes. Which of the following is NOT such a factor? • cell walls • the cytoskeleton • pressure from neighboring cells • the number of mitochondria • structural filaments within the cells

• the number of mitochondria

Which of the following is the most important factor governing a cell's particular type of interaction with other cells • the type of animal the cell came from • the location of the cell within an organism • whether the cell is either an animal cell or a plant cell • the pattern of proteins on the cell's surface • whether the cell is either eukaryotic or prokaryotic

• the pattern of proteins on the cell's surface

In eukaryotic cells, vesicles connect which of the two major organelle compartments? • the smooth endoplasmic reticulum and the peroxisomes • the rough endoplasmic reticulum and the ribosomes • the rough endoplasmic reticulum and the centrioles • the rough endoplasmic reticulum and the Golgi apparatus • the rough endoplasmic reticulum and the nucleus

• the rough endoplasmic reticulum and the Golgi apparatus

In which organelle are lipids synthesized and modified within the eukaryotic cell? • the Golgi apparatus • the smooth endoplasmic reticulum • the lysosome • the vesicle • the rough endoplasmic reticulum

• the smooth endoplasmic reticulum

A cell's interior is considered isotonic to the surrounding fluid when: • the solute concentration is lower within the cell than outside the cell. • the cell's lipid bilayer does not allow any molecules to pass into or out of the cell. • the solute concentration is higher within the cell than outside the cell. • there is an equal number of water molecules immediately outside the cell and inside the cell. • the solute concentrations are the same within and outside the cell.

• the solute concentrations are the same within and outside the cell.

What cell type in animals has a flagellum? • the hair follicle • the sperm cell • the ovum • liver cells • kidney cells

• the sperm cell

Sugar and CO2 are dissolved in water to make carbonated soft drinks. Which of the following is the solute? • the water and the sugar • the water and the CO2 • the CO2 only • the sugar and the CO2 • the sugar only

• the sugar and the CO2