AP Bio Unit 4 Cell Biology

Mastering Biology Questions

A newspaper ad for a local toy store indicates that an inexpensive toy microscope available for a small child is able to magnify specimens nearly as much as the more costly microscope available in your college lab. What is the primary reason for the price difference?

1. The toy microscope usually uses a different wavelength of light source.

2. The toy microscope does not have the same fine control for focus of the specimen.

3. The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.

4. The college microscope produces greater contrast in the specimens.

3. The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.

Cell size is limited by ____.

1. the number of proteins within the plasma membrane

2. surface to volume ratios

3. the size of the endomembrane system

4. the surface area of mitochondria in the cytoplasm

2. surface to volume ratios

Prokaryotes are classified as belonging to two different domains. What are the domains?

1. Bacteria and Protista

2. Archaea and Protista

3. Bacteria and Archaea

4. Bacteria and Eukarya

3. Bacteria and Archaea

Which structure is common to plant and animal cells?

1. central vacuole

2. mitochondrion

3. centriole

4. chloroplast

2. mitochondrion

Which of the following macromolecules leaves the nucleus of a eukaryotic cell through pores in the nuclear membrane?

1. phospholipids

2. DNA

3. amino acids

4. mRNA

4. mRNA

A cell with an extensive area of smooth endoplasmic reticulum is specialized to _____.

1. synthesize large quantities of lipids

2. play a role in storage

3. actively export protein molecules

4. import and export protein molecules

1. synthesize large quantities of lipids

The Golgi apparatus has a polarity, or sidedness, to its structure and function. Which of the following statements correctly describes this polarity?

1. Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.

2. Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.

3. Transport vesicles fuse with one side of the Golgi and leave from the opposite side.

4. All of the listed responses correctly describe polarity characteristics of the Golgi function.

4. All of the listed responses correctly describe polarity characteristics of the Golgi function.

Which of the following is NOT true? Both chloroplasts and mitochondria _____.

1. are part of the endomembrane system

2. have their own DNA

3. have multiple membranes

4. are capable of reproducing themselves

1. are part of the endomembrane system

In a plant cell, DNA may be found _____.

1. only in the nucleus and chloroplasts

2. in the nucleus, mitochondria, chloroplasts, and peroxisomes

3. only in the nucleus

4. in the nucleus, mitochondria, and chloroplasts

4. in the nucleus, mitochondria, and chloroplasts

Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?

1. components of the cytoskeleton

2. membrane proteins of the inner nuclear envelope

3. cellulose fibers in the cell wall

4. free ribosomes and ribosomes attached to the ER

1. components of the cytoskeleton

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?

1. extracellular matrix

2. gap junctions

3. desmosomes

4. tight junctions

2. gap junctions

Which component is cholesterol?

1. B

2. C

3. D

4. E

4. E

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

1. It has no hydrophobic regions.

2. It works against diffusion.

3. It exhibits a specificity for a particular type of molecule.

4. It requires the expenditure of cellular energy to function.

3. It exhibits a specificity for a particular type of molecule.

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal.

Refer to the figure. Initially, in terms of tonicity, the solution in side A with respect to the solution in side B is ___.

1. hypotonic

2. saturated

3. isotonic

4. hypertonic

3. isotonic

The sodium-potassium pump is called an electrogenic pump because it _____.

1. contributes to the membrane potential

2. is used to drive the transport of other molecules against a concentration gradient

3. ionizes sodium and potassium atoms

4. pumps equal quantities of Na+ and K+ across the membrane

1. contributes to the membrane potential

The voltage across a membrane is called the _____.

1. chemical gradient

2. osmotic potential

3. membrane potential

4. electrochemical gradient

3. membrane potential

Ions diffuse across membranes through specific ion channels down _____.

1. their electrochemical gradients

2. their chemical gradients

3. the electrical gradients

4. their concentration gradients

1. their electrochemical gradients

The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane (more acidic outside the cell than inside the cell). Phosphate transport is an example of _____.

1. cotransport

2. passive diffusion

3. facilitated diffusion

4. active transport

1. cotransport

White blood cells engulf bacteria using _____.

1. osmosis

2. phagocytosis

3. receptor-mediated exocytosis

4. pinocytosis

2. phagocytosis

The diameter of a typical eukaryotic cell is approximately ten times the diameter of a typical prokaryote. What is the ratio of the volume of typical eukaryotic:prokaryotic cells?

1. 1000:1

2. 100:1

3. 10:1

1. 1000:1

Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER).

1. Rough ER consists of a network of membranous tubules and sacs called cisternae, whereas smooth ER is less complex.

2. The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.

3. Smooth ER is part of the endomembrane system of the eukaryotic cell, and rough ER is not.

2. The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.

Select the correct statement describing cellular structure or function.

1. Plant and animal cells both carry out cellular respiration, producing ATP.

2. Only plant cells contain chloroplasts, and only animal cells contain mitochondria.

3. Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell.

1. Plant and animal cells both carry out cellular respiration, producing ATP.

What happens when two solutions separated by a selectively permeable membrane reach osmotic equilibrium?

1. Water molecules no longer move between the solutions.

2. Water molecules move between the two solutions, but there is no net movement of water across the membrane.

3. Water molecules continue to move from the hypotonic solution to the hypertonic solution.

2. Water molecules move between the two solutions, but there is no net movement of water across the membrane.

Select the correct statement about osmosis.

1. Osmotic equilibrium cannot be reached unless solute concentrations equalize across the membrane.

2. Osmosis is the diffusion of water molecules across a selectively permeable membrane.

3. If a dead cell is placed in a solution hypotonic to the cell contents, osmosis will not occur.

2. Osmosis is the diffusion of water molecules across a selectively permeable membrane.

Which factors affect the rate of osmotic movement of water?

1. No factors have an effect; the rate of osmosis is constant.

2. Hydrostatic pressure applied to a hypertonic solution separated from a hypotonic solution by a selectively permeable membrane increases osmotic movement across the membrane.

3. The rate of osmosis increases with increasing differences in solute concentrations between two solutions separated by a selectively permeable membrane.

2. The rate of osmosis increases with increasing differences in solute concentrations between two solutions separated by a selectively permeable membrane.

Which statement is correct?

1. The contents of a red blood cell are hyperosmotic to distilled water.

2. A solution of distilled water is hypotonic.

3. A solution of seawater is hypertonic.

1. The contents of a red blood cell are hyperosmotic to distilled water.

Which of the following molecular movements is due to diffusion or osmosis?

1. The sodium-potassium pump pumps three sodium ions out of a neuron for every two potassium ions it pumps in.

2. Cells of the pancreas secrete insulin into the bloodstream.

3. When a plant cell is placed in concentrated salt water, water moves out of the cell.

3. When a plant cell is placed in concentrated salt water, water moves out of the cell.