AP Bio 2

The approximate molarity of the solution in which the mass of the plant pieces would not change is A 0.0 M B 0.1 M C 0.3 M D 0.5 M E 0.7 M

0.3 M

Which of the following cube-shaped cells would be most efficient in removing waste by diffusion? smallest largest

10 um (smallest)

The contents of which dialysis tube are initially isotonic to the distilled water in the beaker? A 1 B 2 C 3 D 4 E 5

5

Which of the following statements best predicts the effect of increasing the permeability of the mitochondrial membranes to large molecules? A ATP production will increase because of an increase in the rate at which proteins diffuse out of mitochondria. B ATP production will increase because of an increase in the mixing of mitochondrial and cytosolic substances. C ATP production will decrease because of an increase in the occurrence of uncontrolled chemical reactions. D ATP production will decrease because of an increase in the surface area of the mitochondrial membranes.

ATP production will decrease because of an increase in the occurrence of uncontrolled chemical reactions.

An investigator wants to understand whether a newly found membrane protein is involved in membrane transport of a certain particle. Which investigation will help determine whether the new membrane protein is a channel protein involved in membrane transport? A Add small nonpolar molecules to the extracellular space and measure the direction of particle movement of the molecules. B Measure the rate of extracellular fluid movement into the intracellular space. C Add more of the proteins to the plasma membrane and measure the rate of the particle movement. D Remove ATP from the intracellular space and measure the rate of the particle movement into the intracellular space.

Add more of the proteins to the plasma membrane and measure the rate of the particle movement.

What is the most likely identity of protein X ? A An enzyme that is involved in transcription B An electron transport protein that participates in respiration reactions C A protein secreted from liver cells into the blood stream that permits proper capillary function D An enzyme that participates in the degradation and recycling of cell components E A building block of the microtubules that are part of the cytoskeleton

An enzyme that participates in the degradation and recycling of cell components

Which of the following best describes the numbered areas? A Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules. B Area 2 is polar, since water has been excluded from this area of the membrane. C Areas 1 and 3 are hydrophilic, since membrane molecules formed covalent bonds with water. D Area 2 is nonpolar, since hydrogen bonds between the adjacent lipids hold the membrane together.

Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules.

Evolved from a photoautotrophic prokaryote A B C D E

B. chlorplasts

Which of the following is a characteristic of mitochondria and chloroplasts that supports the endosymbiotic theory? A Both have bacteria-like polysaccharide cell walls. B Both can reproduce on their own outside of the cell. C Both contain DNA molecules. D Both contain endoplasmic reticulum and Golgi bodies. E Both contain ribosomes that are identical to ribosomes of the eukaryotic cytoplasm.

Both contain DNA molecules.

Which of the following are characteristic of both prokaryotic and eukaryotic cells? A Cytoplasm and a well-defined nucleus surrounded by a membrane B Membranous sites of ATP synthesis, Golgi complex, and ribosomes C Mitochondria, nucleus, and ribosomes D Cell wall, several chromosomes, and cytoplasm E Cell membrane, ribosomes, DNA, and RNA

Cell membrane, ribosomes, DNA, and RNA

The illustration above is a model of a typical beet root cell. Based on the experimental results, which of the following best represents the effect of acetone on the permeability of cellular membranes?

Cell on left has 4 dots in a circle, cell on right has 6 dots outside of rectangle

Which of the following data would support the alternative hypothesis? A Cells with functional aquaporins exhibit low turgor pressure and are hypertonic. B Cells with functional aquaporins exhibit high turgor pressure and are hypotonic. C Cells with mutated aquaporins exhibit an absence of turgor pressure and are completely plasmolyzed. D Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.

Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.

Site of transport of materials into and out of the cell A B C D E

D

Which of the following describes the most likely location of cholesterol in an animal cell? A Embedded in the plasma membrane B Dissolved in the cytosol C Suspended in the stroma of the chloroplast D Bound to free ribosomes

Embedded in the plasma membrane

What evolutionary advantage does compartmentalization of core metabolic processes offer eukaryotes? A Evolution of the mitochondria allowed eukaryotes to perform respiration. B With the evolution of mitochondria in eukaryotes, the Krebs cycle and electron transport chain also evolved. C Evolution of a nucleus in eukaryotes separates the processes of transcription and translation and they can be regulated separately. D A nucleus in bacteria provides separation of respiration from transcription.

Evolution of a nucleus in eukaryotes separates the processes of transcription and translation and they can be regulated separately.

Which of the following describes why a glucose transporter is needed to move glucose into the cell? A Glucose is nonpolar and requires ATP to move across the membrane. B Glucose molecules are polar and need to move from low concentration to high concentration. C Glucose molecules are charged, and charged molecules are only ever actively transported. D Glucose is large and polar and cannot pass through the phospholipid bilayer.

Glucose is large and polar and cannot pass through the phospholipid bilayer.

The same procedure was repeated with a second protein (protein Y). If the function of Y is protein processing and packaging, the most radioactivity would be found in the A Golgi apparatus B Nucleus C Mitochondria D Lysosomes E Cytoplasm

Golgi apparatus

Of the following, which additional investigation can be used to determine when the cells are in an isotonic solution? A Decreasing the salinity of the environment a little at a time until the ATP usage reaches a maximum B Decreasing the salinity of the environment a little at a time until ATP usage reaches a minimum C Increasing the salinity of the environment a little at a time until ATP usage reaches a maximum D Increasing the salinity of the environment a little at a time until the ATP usage reaches a minimum

Increasing the salinity of the environment a little at a time until the ATP usage reaches a minimum

Which of the following statements is true regarding the movement of substances across cell membranes? A Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic. B Ions are able to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged. C Water is able to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are charged. D Water is unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged.

Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic.

Which of the following is true about the structure of the prokaryotic cell represented in the figure? A It possesses cilia and lysosomes. B It has a diploid genome and contains linear DNA. C It has a cell wall exterior to the plasma membrane and contains ribosomes. D It possesses membrane-bound organelles and a flagellum.

It has a cell wall exterior to the plasma membrane and contains ribosomes.

Which of the following best explains how the extensive folding of the inner mitochondrial membrane benefits a eukaryotic cell? A It enlarges the volume of the matrix, which allows for more enzymatic reactions. B It increases the area available for proteins involved in energy transfer. C It allows for greater area for the diffusion of water into and out of the mitochondria. D It provides better insulation for reactions in the matrix from conditions outside the mitochondria

It increases the area available for proteins involved in energy transfer.

The active transport pump used to move sodium ions across the membranes of gill cells in a freshwater fish has each of the following characteristics EXCEPT: A It uses osmosis to carry sodium ions into the cells. B It requires energy. C It has a specific binding site for ATP. D It has a specific binding site for sodium ions. E It is a protein.

It uses osmosis to carry sodium ions into the cells.

Which of the following processes is most likely to occur as a result of an animal cell receiving a signal to initiate apoptosis? A Ribosomes will translate mRNA to produce proteins. B Vesicles will release extracellular growth factors via exocytosis. C Lysosomes will release digestive enzymes into the cytosol. D Vacuoles will fuse with the cellular membrane.

Lysosomes will release digestive enzymes into the cytosol.

Which of the following modifications to the experimental design would improve the reliability of the results presented in Figure 1 ? A Measuring blood glucose levels in human patients who have type 1 diabetes B Measuring blood glucose levels in a group of mice that were not given STZ C Using a drug that destroys both mouse β-cells and hESC-β cells D Injecting the mice in the experiment with sucrose or fructose

Measuring blood glucose levels in a group of mice that were not given STZ

Which of the following best supports the statement that mitochondria are descendants of endosymbiotic bacteria-like cells? A Mitochondria and bacteria possess similar ribosomes and DNA. B Mitochondria and bacteria possess similar nuclei. C Glycolysis occurs in both mitochondria and bacteria. D Both mitochondria and bacteria have microtubules. E Neither mitochondria nor bacteria possess chloroplasts.

Mitochondria and bacteria possess similar ribosomes and DNA.

Which of the following provides the weakest evidence that mitochondria were once free-living prokaryotes? A Mitochondrial ribosomes resemble those of prokaryotes. B Mitochondria have DNA that is circular and does not have associated protein. C Enzyme pathways on mitochondrial membranes resemble those found on modern prokaryote membranes. D Mitochondria reproduce by a process similar to binary fission. E Mitochondria and prokaryotes both are found in a variety of sizes.

Mitochondria and prokaryotes both are found in a variety of sizes.

The manner in which several different ions and molecules move through a cell membrane is shown in the diagram above. For each ion or molecule, the relative concentration on each side of the membrane is indicated. Which of the following accurately describes one of the movements taking place? A Glucose is transported into the cell by active transport. B Na+ is transported into the cell by active transport. C The movement of glucose through the membrane requires ATP hydrolysis. D Na+ transport out of the cell requires ATP hydrolysis.

Na+ transport out of the cell requires ATP hydrolysis.

Which of the following statements best explains the processes of passive and active transport? A Passive transport is the net movement of substances down a concentration gradient that requires metabolic energy. Active transport is the movement of substances up a concentration gradient that does not require energy. B Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy. C Passive transport is the net movement of substances up a concentration gradient that requires metabolic energy. Active transport is the movement of substances down a concentration gradient that does not require metabolic energy. D Passive transport is the net movement of substances up a concentration gradient that does not require metabolic energy. Active transport is the movement of substances down a concentration gradient that requires energy.

Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy.

A student placed a semipermeable membrane inside a U-shaped channel with two chambers, as shown. The membrane permits the movement of water but not salt. The student wants to vary the rate of osmosis that occurs across the membrane. Which of the following experimental designs will result in the fastest net rate of water movement into chamber A? A Placing salt water in chamber A and distilled water in chamber B B Placing distilled water in both chambers C Placing distilled water in chamber A and salt water in chamber B D Placing salt water in both chambers

Placing salt water in chamber A and distilled water in chamber B

Which of the following components of the cell membrane is responsible for active transport? A Phospholipid B Protein C Lipid D Phosphate E Cholesterol

Protein

Synthesized at the ribosome A Proteins B Carbohydrates C Nucleic acids D Lipids E Steroids

Proteins

Prokaryotic and eukaryotic cells generally have which of the following features in common? A A membrane-bound nucleus B A cell wall made of cellulose C Ribosomes D Flagella or cilia that contain microtubules E Linear chromosomes made of DNA and protein

Ribosomes

Which of the following functional differences between the rough and smooth endoplasmic reticulum A Rough ER breaks down toxic substances, and smooth ER only transports them out of the cell. B Rough ER can synthesize and package lipids for export, and smooth ER cannot. C Rough ER can produce ATP, and smooth ER cannot. D Rough ER can synthesize and package proteins for export, and smooth ER cannot.

Rough ER can synthesize and package proteins for export, and smooth ER cannot.

Assuming a negligible pressure potential, which of the following best predicts the net movement of the small diffusible solutes and water in the second experiment (Table 2) ? A Small diffusible solutes will diffuse into the grape cells, followed by water. B Small diffusible solutes will diffuse out of the grape cells and water will diffuse into the cells. C Small diffusible solutes will diffuse out of the grape cells, followed by water. D Small diffusible solutes will diffuse into the grape cells and water will diffuse out of the cells.

Small diffusible solutes will diffuse into the grape cells, followed by water.

The figure above represents a rough endoplasmic reticulum. Which of the following best describes the role of the structure labeled Y? A Structure Y contributes the raw materials required for the synthesis of proteins. B Structure Y packages proteins for export from the cell. C Structure Y is the location where proteins are synthesized. D Structure Y contains enzymes that cut and activate proteins.

Structure Y is the location where proteins are synthesized.

Which of the following organelles modifies and packages for secretion the materials produced by the ribosomes? A The chloroplast B The Golgi apparatus C The nucleus D The nucleolus

The Golgi apparatus

Based on the model, the newly synthesized protein is transported directly from the endoplasmic reticulum to which of the following? A The nucleus B The plasma membrane C The Golgi complex D The extracellular space

The Golgi complex

Which of the following best describes the condition expected after 24 hours? A The bag will contain more water than it did in the original condition. B The contents of the bag will have the same osmotic concentration as the surrounding solution. C Water potential in the bag will be greater than water potential in the surrounding solution. D Starch molecules will continue to pass through the bag. E A glucose test on the solution in the bag will be negative.

The bag will contain more water than it did in the original condition.

Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data? A At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia. B The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases. C The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration. D In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.

The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.

In an experiment, the efficiency of oxygen exchange across the plasma membrane is being assessed in four artificial red blood cells. The table above lists some properties of those artificial cells. Other conditions being equal, which artificial cell is predicted to be the most efficient in exchanging oxygen with the environment by diffusion? A The cuboidal cell B The tetrahedral cell C The cylindrical cell D The spherical cell

The cuboidal cell

Which of the following, if true about the drug, best supports the alternative hypothesis that the new drug will exhibit simple diffusion across plasma membranes? A The drug is a small nonpolar molecule. B The drug is a small charged molecule. C The drug is a large polar molecule. D The drug is a large charged molecule.

The drug is a small nonpolar molecule.

Based on the data in Table 1, which of the following best evaluates the student's hypothesis? A The hypothesis is supported because the mass of the grape decreased in the grape juice. B The hypothesis is supported because the grape juice has a greater solute potential than the grape has. C The hypothesis is not supported because the grape was isotonic to the grape juice. D The hypothesis is not supported because the mass of the grape increased in the grape juice.

The hypothesis is not supported because the mass of the grape increased in the grape juice.

Muscle cells have high ATP demands. Which of the following is a scientific claim about how the structure of the mitochondria in muscle cells should be different than it is in other cells because of the high energy demands of mitochondria? A The inner membrane of the mitochondria in muscle cells should have more folds to increase the surface area, allowing more ATP to be synthesized. B The inner membrane of the mitochondria in muscle cells should be more permeable to large enzymes, allowing the same reactions to occur in both compartments of the mitochondria. C The outer membrane of the mitochondria in muscle cells should be thicker, allowing more rapid diffusion of molecules into the mitochondria. D The outer membrane of the mitochondria of muscle cells should have more folds, increasing the surface area for faster diffusion of molecules from the cytoplasm.

The inner membrane of the mitochondria in muscle cells should have more folds to increase the surface area, allowing more

Which of the following outcomes will most likely result from a loss of ion pump function in the cell's lysosomes? A The internal pH of the lysosomes will decrease, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food. B The internal pH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food. C The internal pH of the lysosomes will decrease, which will activate hydrolytic enzymes and enhance the intracellular digestion of food. D The internal pH of the lysosomes will increase, which will activate hydrolytic enzymes and enhance the intracellular digestion of food.

The internal pH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food.

Which of the following statements is most consistent with the data in the table? A In response to the hypotonic environment in which freshwater fish live, they excrete ammonia in concentrated urine or across their gills. B The kidneys of reptiles and birds are highly efficient because little water is needed to excrete uric acid. C Birds excrete ammonia in addition to uric acid, and the ratio of the two substances is independent of whether the birds are primarily terrestrial or aquatic species. D The similar regulation of extracellular fluid volume and composition in all the organisms suggests conservation of kidney structure throughout evolution.

The kidneys of reptiles and birds are highly efficient because little water is needed to excrete uric acid.

Which of the following best explains how molecules such as O2 and CO2 can move across the membrane of a cell? A The majority of the cell membrane contains protein channels that allow this type of molecule into the cell. B The majority of the cell membrane is nonpolar, which allows small, nonpolar molecules to freely cross. C The phospholipids of the membrane are tightly packed, so only small molecules and ions can fit between phospholipids. D ATP is hydrolyzed to provide energy to help O2 and CO2 move against their concentration gradient and across the membrane.

The majority of the cell membrane is nonpolar, which allows small, nonpolar molecules to freely cross.

A pathogenic bacterium has been engulfed by a phagocytic cell as part of the nonspecific (innate) immune response. Which of the following illustrations best represents the response?

The one with two dark lysosomes in the middle

The diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria? A The organism is surrounded by a cell wall. B The organism contains ribosomes. C The organism does not have a nuclear membrane surrounding its genetic material. D The organism is not capable of making or providing itself with ATP.

The organism does not have a nuclear membrane surrounding its genetic material.

If ADH secretion is inhibited, which of the following would initially result? A The number of aquaporins would increase in response to the inhibition of ADH. B The person would decrease oral water intake to compensate for the inhibition of ADH. C Blood filtration would increase to compensate for the lack of aquaporins. D The person would produce greater amounts of dilute urine.

The person would produce greater amounts of dilute urine.

Which of the following best explains how the phospholipid bilayer of a transport vesicle contributes to cellular functions? A The phospholipid bilayer allows the vesicle to fuse with the Golgi apparatus and the plasma membrane, allowing the exocytosis of proteins. B The phospholipid bilayer physically connects the nuclear envelope to the rough endoplasmic reticulum, thus increasing the rate of transcription and translation. C The phospholipid bilayer of a transport vesicle contains chemicals that digest the proteins made in the rough endoplasmic reticulum. D The phospholipid bilayer contains enzymes that catalyze the conversion of hydrogen peroxide to water and oxygen.

The phospholipid bilayer allows the vesicle to fuse with the Golgi apparatus and the plasma membrane, allowing the exocytosis of proteins.

From the initial conditions and results described, which of the following is a logical conclusion? A The initial concentration of glucose in the bag is higher than the initial concentration of starch in the bag. B The pores of the bag are larger than the glucose molecules but smaller than the starch molecules. C The bag is not selectively permeable. D A net movement of water into the beaker has occurred. E The molarity of the solution in the bag and the molarity of the solution in the surrounding beaker are the same.

The pores of the bag are larger than the glucose molecules but smaller than the starch molecules.

Which of the following best explains the advantage these projections provide the cell? A The projections increase the volume of the cell without affecting the surface area, which increases the metabolic needs of the cell. B The projections increase the surface area-to-volume ratio of the cell, which allows for more efficient nutrient exchange with the environment. C The projections increase the speed at which an individual molecule can move, resulting in faster nutrient exchange with the environment. D The projections increase the selectivity of the membrane because the small size of the projections limits the number of transport proteins that can be embedded in the membrane.

The projections increase the surface area-to-volume ratio of the cell, which allows for more efficient nutrient exchange with the environment.

Which of the following best explains why larger grapes have a different rate of water absorption per gram of mass than smaller grapes do? A The rate is slower because smaller grapes have a larger surface-area-to-volume ratio than the larger grapes do. B The rate is slower because larger grapes have a larger surface-area-to-volume ratio than the smaller grapes do. C The rate is slower because smaller grapes can expand more than larger grapes to hold excess water. D The rate is slower because larger grapes have more volume to hold excess water than smaller grapes do.

The rate is slower because smaller grapes have a larger surface-area-to-volume ratio than the larger grapes do.

Which of the following statements best explains the observations represented in Figure 1 ? A There was a net movement of sucrose out of the cell suspended in the sugar solution and a net movement of sucrose into the cell suspended in the distilled water. B There was a net movement of sucrose into the cell suspended in the sugar solution and a net movement of sucrose out of the cell suspended in the distilled water. C There was a net movement of water out of the cell suspended in the sugar solution and a net movement of water into the cell suspended in the distilled water. D There was a net movement of water into the cell suspended in the sugar solution and a net movement of water out of the cell suspended in the distilled water.

There was a net movement of water out of the cell suspended in the sugar solution and a net movement of water into the cell suspended in the distilled water.

Which of the following statements is true about the Krebs (citric acid) cycle and the Calvin (light-independent) cycle? A They both result in a net production of ATP and NADH. B They both require a net input of ATP. C They both result in a release of oxygen. D They both take place within the cytoplasmic matrix. E They both are carried out by enzymes located within an organelle matrix.

They both are carried out by enzymes located within an organelle matrix.

A mutation in the upland cotton plant causes the development of chloroplasts with a single outer membrane and no internal membranes. Which of the following would most likely be observed in chloroplasts of cotton plants with this mutation? A They would be unable to remove waste products, because internal transport proteins would not be present. B They would be unable to generate the ATP and NADPH needed to make sugars, because these processes occur on membranes within the chloroplast. C They would be unable to take up carbon dioxide, because CO2CO2 is transported into the chloroplast in membrane-bound vesicles. D They would be unable to move within the cell, because only organelles with double membranes are mobile.

They would be unable to generate the ATP and NADPH needed to make sugars, because these processes occur on membranes within the chloroplast.

The figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together? A To synthesize lipids and modify toxic substances in order to render them harmless B To synthesize and isolate proteins for secretion or for use in the cell C To catabolize nutrients and produce ATP for intracellular energy storage D To synthesize all ribosomal proteins

To synthesize and isolate proteins for secretion or for use in the cell

The student analyzed the data from the investigation and concluded that the estimate of the mean of one treatment group was unreliable. Which of the following identifies the treatment group most likely to have provided an unreliable estimate of the mean, and correctly explains why the estimate appears unreliable? A Treatment group II; it has a lower than expected mean absorbance and the largest standard error of the mean. B Treatment group III; it has a higher than expected mean absorbance and the largest standard error of the mean. C Treatment group IV; it has a higher than expected mean absorbance and the smallest standard error of the mean. D Treatment group V; it has a lower than expected mean absorbance and the smallest standard error of the mean.

Treatment group II; it has a lower than expected mean absorbance and the largest standard error of the mean.

Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane? A Increase the solute concentration in the solution B Use a small, nonpolar solute instead of a protein C Increase the temperature of the solution D Add artificial aquaporins to the membrane

Use a small, nonpolar solute instead of a protein

Which of the following best predicts which diagrammed microscope view the laboratory worker would see and best explains why? A View 1 because RBC membranes are freely permeable to water B View 2 because the RBCs use energy to allow sodium entry and to pump water out C View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells D View 3 because the sodium-potassium pumps in the RBC membranes use energy to keep the sodium out but allow water to freely flow into the cells

View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells

Which of the following scientific questions is most relevant to the model represented in the figure above? A Is ATP required for the transportation of sugars across the outer mitochondrial membrane? B Do the types of phospholipids in a membrane affect the rate at which molecules enter a cell by passive diffusion? C Which molecular substance is actively transported across the plasma membrane? D How does temperature affect the movement of molecules into lysosomes?

Which molecular substance is actively transported across the plasma membrane?

Based on the data from the investigation, which of the following is the best scientific question about organisms living in water that is polluted with organic solvents? A Do organisms without pigments have a selective advantage in polluted environments? B Will organisms living in polluted environments exhibit detrimental effects from an increased permeability of their cellular membranes? C Will organic solvents from the environment become incorporated into the cell membranes of organisms living in polluted environments? D Should governments place more stringent restrictions on the release of organic solvents into aquatic ecosystems?

Will organisms living in polluted environments exhibit detrimental effects from an increased permeability of their cellular membranes?

Site of glucose synthesis A B C D E

b. chloroplasts

The last part of the metamorphosis of a tadpole to an adult frog results in the disappearance of the tail. This stage of development most likely occurs by A cells of the tail dying and the nutrients being absorbed and reused by the body B shedding of the tail so energy is not spent on maintenance of an unneeded part C bilateral division of the tail and fusion with the developing hind limbs D individual cells of the tail migrating to the developing gonads

cells of the tail dying and the nutrients being absorbed and reused by the body

Simple diffusion and facilitated diffusion are related in that both A require protein carriers B depend on a concentration gradient C occur via contractions of cytoskeletal elements attached to membrane proteins D are endergonic processes and thus require the hydrolysis of ATP E occur in eukaryotic cells but not in prokaryotic cells

depend on a concentration gradient

All of the following changes would be likely to decrease the rate of transpiration at 8 A.M. EXCEPT A causing the stomata to close B increasing the humidity of the atmosphere C increasing the water potential of the atmosphere D increasing the water potential of the soil E placing the plant in total darkness

increasing the water potential of the soil

All of the following cell components are found in prokaryotic cells EXCEPT A DNA B ribosomes C cell membrane D nuclear envelope E enzymes

nuclear envelope

Water enters and leaves the plant cells primarily by A endocytosis B phagocytosis C osmosis D active transport E facilitated diffusion

osmosis