Ap Biology Exam #2 (MCQ)

Researchers propose a model to explain variation in phytoplankton cell sizes in a marine environment. They base their model on the idea that smaller cells absorb nutrients more efficiently. The researchers predict that the mean diameter of phytoplankton cells will change by 50 micrometers for every 5-kilometer increase in distance from the shore because of a gradual decrease in nutrient availability. To test their model, the researchers determine that the phytoplankton cells found closest to shore have a mean diameter of 900 micrometers.

Based on the model, what will be the mean diameter of the phytoplankton cells that are found 25 kilometers from shore?

650 micrometers

A spherical bacterial cell has a radius of 3μm3μm. The human egg cell has a radius of 100μm100μm.

Which statement correctly indicates the cell that is able to more efficiently exchange materials with the external environment and provides a correct explanation?

The bacterial cell, because it has the largest surface-to-volume ratio.

Two different models of a living cell are represented in the figure.

Of the two cells represented in the figure, which would likely be more efficient at exchanging substances with the surrounding environment?

Cell A, because it has the larger surface-area-to-volume ratio.

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?

The cuboidal cell

A cell is treated with a drug that prevents the formation of new lysosomes. The 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?

Golgi apparatus

The figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together?

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

Glucose synthesis

B. Chloroplast

Site of conversion of chemical energy of glucose to ATP

A. Mitochondria

Site of modification and packaging of proteins and lipids prior to export from the cell

C. Golgi Apparatus

What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane?

Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores.

In a mesophyll cell of rule of a left the synthesis of atp occur in

mitochondria and chloroplasts

In the first step of an experiment, rat liver cells were exposed for 5 minutes to amino acids labeled with a radioactive isotope. The cells were then washed to stop any further incorporation of radioactive amino acids. The cells were sampled periodically thereafter, and the radioactivity of a certain protein (protein X) was measured in various cell components, as shown below.

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

Golgi apparatus

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 from it is in other cells because of the high energy demands of mitochondria?

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

Which statement best explains why correct protein folding is critical in the transmembrane protein shown above?

Interactions of the hydrophobic and hydrophilic amino acids help to anchor the protein in the membrane.

The student prepared identical samples of beet root tissue and incubated in the specific solution for that group. At the end of the incubation period, the student measured the absorbance of 460nm light. The results of the the experiment are shown in the table above.

Based on the data from the investigation, which of the following is the best scientific question about organisms living in water that's polluted with organic solvents.

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

Which of the following best describes the numbered areas?

Areas 1 and 3 are hydrophilic, since membrane molecules formed covalent bonds with water.

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.

A. II

B.

D.

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.
Figure 1. A model showing a cell engulfing a smaller cell
Which of the following provides evidence to best support the researchers' claim?

The organelle has a double membrane

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

Site of transport of materials into and out of the cell

D. Cell Wall