Chapter 3

Question 1

What are the three types of protein fibers that make up the cytoskeleton?

Answer 1

microtubules, intermediate filaments, and microfilaments

Question 2

Which of the following statements about the cell theory is correct?

Answer 2

All living organisms are made up of one or more cells.

All cells arise from other, pre-existing cells

Question 3

Drugs called beta-blockers do all of the following except:
bind to the cytoplasmic side of a receptor protein.
reduce outward symptoms of anxiety.
block signaling through adrenaline receptors.
reduce high blood pressure.

Answer 3

bind to the cytoplasmic side of a receptor protein.

Question 4

In an experiment, you measure the concentration of a polar molecule inside and outside 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 is your best hypothesis for the process you are observing?

Answer 4

active transport

Question 5

Which of the following allows the passage of small molecules between animal cells?
	tight junctions
	desmosomes
	nucleoli
	black holes

Answer 5

gap junctions

Question 6

Which of the following types of human cells does NOT contain DNA?

Answer 6

red blood cells

Question 7

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

Answer 7

plasma membrane

Question 8

If the solution surrounding a cell contains the same amount of solute as the cytoplasm, the osmotic condition is said to be:

Answer 8

isotonic

Question 9

An ostrich egg is to a cell as:

Answer 9

a giant sequoia is to a tree.

Correct! The ostrich egg is the largest type of cell, whereas the giant sequoia is the largest type of tree.

Question 10

What cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings

Answer 10

plasma membrane

Question 11

______________ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells.

Answer 11

vesicles

Question 12

mitochondria have their own..

Answer 12

dna

Question 13

Which of the following is NOT true about prokaryotic cells?
They have a circular loop of DNA instead of multiple linear DNA molecules.
They are always single-celled organisms, and they never contain mitochondria.
They have a rigid cell wall instead of a plasma membrane.
They may have flagella, but they never have cilia.
They lack a nucleus, but they do have ribosomes.

Answer 13

They have a rigid cell wall instead of a plasma membrane.

Question 14

Which of the following statements is TRUE about a plasma membrane?
The molecules that make up the membrane are phospholipids.
It is a rigid structure that protects the cell like a shell.
The molecules that make up most of the plasma membrane are polar at their heads and tails.
It is composed of a single layer of phospholipids.
The molecules making up the plasma membrane are locked in place.

Answer 14

The molecules that make up the membrane are lipids.

Question 15

The transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as:

Answer 15

osmosis

Question 16

Which is NOT true about chloroplasts and mitochondria?
mitochondria break down food energy to make ATP
animal cells don’t have chloroplasts
chloroplasts produce food from sunlight energy
plants have chloroplasts instead of mitochondria
both mitochondria and chloroplasts are involved with energy transformation

Answer 16

plants have chloroplasts instead of mitochondria

Question 17

Which of the following statements is correct?
Centrioles are structures found in both plant and animal cells.
Centrioles are not found in plant cells, and chloroplasts, cell walls and vacuoles are not found in animal cells.
Animal cells and plant cells are entirely different types of cells, not even sharing a common ancestor.
Animal cells and plant cells share a common prokaryotic ancestor.
Animal cells contain ribosomes, but like prokaryotic cells, plant cells do not.

Answer 17

Centrioles are not found in plant cells, and chloroplasts, cell walls and vacuoles are not found in animal cells.

Question 18

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

Answer 18

bind to the cytoplasmic side of a receptor protein.

Question 19

The movement of molecules across a membrane from an area of high concentration to one of low concentration is best described as:

Answer 19

passive transport

Question 20

How do beta-blockers function to reduce anxiety?

Answer 20

The drugs bind to beta-adrenergic receptors and block adrenaline from having any function.

Question 21

The role of cholesterol in the plasma membrane of animal cells is to:

Answer 21

keep the plasma membrane flexible, especially at low temperatures.

Question 22

Endosymbiosis

Answer 22

According to this theory, mitochondria and chloroplast are thought to have originally been prokaryotes capable of cellular respiration and photosynthesis, respectively, that were engulfed by a cell that developed into a eukaryotic cell.

Question 23

invagination

Answer 23

the cell membrane folded in on itself to form inner compartments that specialized to become the membranous organelles

Question 24

why is it called a mosaic?

Answer 24

The plasma membrane behaves like a fluid because many membrane molecules can move around within their respective layer of the phospholipid bilayer, and it is described as a mosaic because it is composed of a variety of proteins, lipids, and carbohydrates

Question 25

2. 7. The Golgi apparatus:

Answer 25

processes and packages proteins, lipids, and other molecules.

Question 26

Diffusion across the cell’s outer membrane:

Answer 26

occurs without an input of energy

Question 27

Which statement is NOT part of the modern cell theory?

Answer 27

Cells are able to synthesize their entire complement of biomolecules.

Question 28

In Tay-Sachs disease, a genetic mutation causes a malfunction in a certain organelle that leads to a backup of molecules and proteins, ultimately interfering with the entire functioning of the cell. Which organelle is primarily affected by this disease?

Answer 28

Lysosomes

Question 29

A scientist tries to build a eukaryotic cell in her laboratory. She remembers to include most of the organelles, but forgets one. Among other abnormalities, her newly created cell cannot synthesize the enzymes needed to detoxify drugs and poisons. Which organelle is missing?

Answer 29

smooth er

Question 30

Which of the following is NOT true about prokaryotic cells?

Answer 30

all have a rigid cell wall instead of a plasma membrane

Question 31

The pH of the liquid inside a lysosome is acidic, about 4.5. The molecules normally found inside the lysosome are designed to work best at this pH. Which of the follow statements is the BEST explanation for why the pH of the lysosome interior is so low?

Answer 31

Protective: if the corrosive broth of a lysosome ever leaked out, the digestive enzymes in it would become non-functional in the higher pH of the cytoplasm

Question 32

Which of the following is NOT a correct statement about passive transport across the cell membrane?

Answer 32

Passive transport increases entropy in a system.

Question 33

Cellular “fingerprints”:

Answer 33

can help the immune system distinguish “self” from “non-self.

Question 34

Which of the following describes pinocytosis?

Answer 34

A cell performs endocytosis, bringing in dissolved particles and liquids.

Question 35

smooth er function

Answer 35

synthesizes lipids and detoxifies molecules.

Question 36

Facilitated diffusion of magnesium ions (Mg++) would occur OUT of a cell if the Mg++ concentration was ________ outside the cell than inside, and ________

Answer 36

lower, Mg++ could move directly through the phospholipid bilayer of the membrane

Question 37

The “fingerprint” found on the outsides of cells is the BEST underlying explanation for:

Answer 37

why you can’t catch HIV by casual contact

Question 38

In chemistry class we learn the rule “like dissolves like” when studying why polar substances dissolve in each other (like sucrose in water) and why non-polar substances dissolve in each other (like fats in oil). Which of the following statements illustrates this rule?

Answer 38

Transmembrane proteins remain in the plasma membrane even though they are not attached to anything.

Question 39

pinocytosis?

Answer 39

A cell performs endocytosis, bringing in dissolved particles and liquids.

Question 40

Which of the following organelles contains a small circular loop of DNA

Answer 40

mitochondria