AP Bio Unit 2 Test
What feature is unique to both archaea and bacteria?
Bacterial cells walls contain peptidoglycan. Archaeal cells walls do not
Which of the following describes the most likely location of cholesterol in an animal cell?
Embedded in the plasma membrane
What part of the cell membrane is responsible for active transport?
Protein
What cube shaped cells would be most efficient in removing waste by diffusion?
10 um > 40 um
Simple diffusion and facilitated diffusion are related in that both...
Involve movement down the concentration gradient.
Cells contain smaller components called organelles that are necessary for a cells survival. Organelle functions have often been compared to components of larger systems. What following functional differences between the rough and smooth er is explained by the structural differences between them?
Rough ER can synthesize and package proteins for export and smooth ER can't
Grape Lab - A student peeled the skins from grapes, exposing cells with membranes that are only permeable to water and small diffusible solutes. The student measured the mass of the peeled grapes. The student then placed each peeled grape into one of five solutions. After 24 hours, the student removed the peeled grapes from the solutions, measured their final mass, and calculated the percent change in mass (Table 1). Based on Table 1, which of the following percentages is closest to the solute concentration of the grape?
5.5%
Based on the model, what will be the mean diameter of the phytoplankton cells that are found 25 kilometers from shore?
650 micrometers
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.
A researcher claims that the synthesis of ATP from ADP and inorganic phosphate (Pi) is essential to cellular function. Which of the following statements best helps justify the researcher's claim?
ATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy.
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?
Add more of the proteins to the plasma membrane and measure the rate of the particle movement.
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?
Cube
When a substance moves across the plasma membrane along a concentration gradient at a rate faster than would be expected by simple diffusion alone but without the expenditure of metabolic energy, the process is best described as
Facilitated Diffusion
Grape Lab - Based on Table 1, which of the following best explains the difference in water potential between certain solutions and the grapes?
Grape soda and NaCl have a lower water potential because these two solutions caused the grape to lose water.
The illustration shows the active transport of hydrogen ions through a membrane protein. Which of the following best predicts the effect of not having ATP available to supply energy to this process?
H+ ions will stop moving through the protein.
Which of the following best predicts the effect of not having ATP available to supply energy to this process (active transport)
Hydrogen ions will stop moving through the protein
Plant cell walls are composed of cellulose, while fungal cell walls are composed of chitin. Which of the following observations would best support the alternative hypothesis described above?
In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane.
Relative salinity of environment (x) ; Relative use of ATP (y) // which investigation can be used to determine when the cells are in an isotonic solution?
Increasing salinity of the environment a little at a time until the ATP usage reaches a minimum
The rate of transpiration, the flow of water through the stem, and leaf water potential are measured in a tree during a 24-hour period under normal environmental conditions. The results from these measurements are shown in the graphs below. (Diagram for #97-100)All of the following changes would be likely to decrease the rate of transpiration at 8 A.M. EXCEPT
Increasing the water potential of the soil
Dialysis Lab - If instead of the bag the potatoes were placed in the beaker of distilled water which of the following would be true of the potato slice?
It would gain mass
Dialysis Lab - Which of the following best describes the condition expected after 24 hours?
It would gain mass (24)
Which of the following processes is most likely to occur as a result of an animal cell receiving a signal to initiate apoptosis?
Lysosomes will release digestive enzymes into the cytosol.
Which of the following best supports the statement that mitochondria are descendants of endosymbiotic bacteria-like cells?
Mitochondria and bacteria possess similar ribosomes and DNA
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?
Na+ transport out of the cell requires ATP hydrolysis
If ATP breakdown (hydrolysis) is inhibited, which of the following types of movement across cell membranes is also inhibited?
Passage of a solute against its concentration gradient
Which of the following statements best explains the processes of passive and active transport?
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?
Placing salt water in chamber A and distilled water in chamber B
Define Plasmolysis
Plant cells exposed to low water potential. Water moves out causing it to shrink
Prokaryotic and eukaryotic cells generally have which of the following features in common?
Ribosomes
Dialysis Lab - Which of the following best represents the amount of starch water and glucose in the dialysis bag over the course of the investigation
Starch is constant, water increases, glucose decreases
Which of the following organelles modifies the packages for secretion the materials produced by the ribosomes?
The Golgi Apparatus
A cell is treated with drug that prevents formation of new lysosomes. cell continues to transcribe the genes that code for the hydrolytic enzymes that are normally found in lysosomes and continues to translate the mRNAs for those proteins on membrane-bound ribosomes. The hydrolytic enzymes are most likely to accumulate in which of the following cellular structures?
The Golgi Apparatus (hydrolytic enzymes)
Based on the information presented, which of the following is the most likely explanation for a buildup of cholesterol molecules in the blood of an animal?
The animal's body cells are defective in endocytosis.
Which of the following best describes the condition expected after 24 hours?
The bag will contain more water than it did in the original condition.
Intravenous (IV) solutions administered to patients are normally isotonic. Which of the following is most likely if an IV of distilled water is administered to a patient?
The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood.
A team of biologists develop a new drug, and one team member hypothesizes that the drug is incapable of freely passing across the plasma membrane and requires the help of membrane proteins to enter cells. Alternatively, another biologist on the team hypothesizes that the drug can diffuse passively across the plasma membrane like O2 and CO2 can. 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?
The drug is a small nonpolar molecule
The model below shows the structure of a portion of a plasma membrane in an animal cell.Which statement best explains the orientation of the phospholipid molecules in this model?
The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments.
Grape Lab - A student hypothesizes that the solute concentration of grape juice is higher than the solute concentration of the actual grape because the grape juice has added sugar. Based on the data in Table 1, which of the following best evaluates the student's hypothesis?
The hypothesis is not supported because the mass of the grape increased in the grape juice.
Researchers claimed that a particular organelle originated from a free-living prokaryotic cell that was engulfed by a larger cell, as shown in Figure 1. Which of the following provides evidence to best support the researchers' claim?
The organelle has a double membrane.
Dialysis Lab - from the initial conditions and results described, which of the following is a logical conclusion?
The pores in the bag are larger than the glucose molecules but smaller than the starch
Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes. Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?
They have highly folded membranes
A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell. Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane?
Use a small, nonpolar solute instead of a protein
Which statement best describes the effect on water transport across the cell membrane if the aquaporin in the figure ceases to function?
Water molecules will still be able to move across the cell membrane but at a slower rate.
Which of the following scientific questions is most relevant to the model represented in the figure above?
Which molecular substance is actively transported across the plasma membrane
CO2 enters the cell through...
simple diffusion
