exam 2 hw and review

Question 1

Which structure is NOT part of the endomembrane system?

Answer 1

Peroxisome

Question 2

Which structure is the site of the synthesis of proteins that may be exported from the cell?

Answer 2

rough ER

Question 3

Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?

Answer 3

Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.

Question 4

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?

Answer 4

smooth ER

Question 5

In a plant cell, DNA may be found _____.

Answer 5

in the nucleus, mitochondria, and chloroplasts

Question 6

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to _____.

Answer 6

separate chromosomes during cell division

Question 7

The fluid mosaic model of the membrane proposes that membranes _____.

Answer 7

consist of protein molecules embedded in a fluid bilayer of phospholipids

Question 8

The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.

Answer 8

increasing the percentage of unsaturated phospholipids in the membrane

Question 9

Some regions of the plasma membrane have a higher concentration of cholesterol molecules. At higher temperatures, these regions _____.

Answer 9

are less fluid than the surrounding membrane

Question 10

Why are lipids and proteins free to move laterally in membranes?

Answer 10

There are only weak hydrophobic interactions in the interior of the membrane.

Question 11

What is the role of chief cells within the stomach?

Answer 11

Secrete pepsinogen, an inactive form of the protease, pepsin

Question 12

The agents that help emulsify fats are stored in the ______.

Answer 12

gallbladder

Question 13

Digestion of fats occurs in the ____.

Answer 13

small intestine

Question 14

Stomach cells are moderately well adapted to the acidity and protein-digesting activities in the stomach by having _____.

Answer 14

a thick, mucous secretion and active mitosis of epithelial cells

Question 15

The highest rate of nutrient absorption occurs in the _____.

Answer 15

small intestine

Question 16

The absorption of fats differs from that of carbohydrates in that _____.

Answer 16

most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood

Question 17

In a healthy person, after a large meal, the production of _____ will increase. After fasting, the production of _____ will increase.

Answer 17

insulin; glucagon

Question 18

Constipation can result from the consumption of a substance that _____.

Answer 18

promotes water reabsorption in the large intestine

Question 19

All of the following are part of a prokaryotic cell EXCEPT _____.

• A chromosome
• A plasma membrane
• All are part of a prokaryotic cell
• Ribosomes

Answer 19

all are part of a prokaryotic cell

Question 20

The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you most likely expect to be the immediate consequence?

Answer 20

A change in the shape of the nucleus

Question 21

Which of the following is not a reason why we need to ingest and digest food?

• Obtain essential nutrients
• Provides chemical energy for the body
• To generate the raw materials need for the biosynthesis of large biological molecules
• All are reasons

Answer 21

all are reasons

Question 22

Which of the following is not an essential nutrient?

Answer 22

nucleic acids

Question 23

Certain nutrients are considered “essential” in the diets of some animals because _____.

Answer 23

these animals are not able to synthesize these nutrients

Question 24

Iron is an example of an essential _____.

Answer 24

mineral

Question 25

One a Day multivitamin for women contains only 21% of the daily recommended value of vitamin K. The most likely reason that is found at less than 100% is ____.

Answer 25

it is dangerous to overdose on fat-soluble vitamins

Question 26

Which of the following are not part of the alimentary canal?

Answer 26

liver

Question 27

The function of mechanical digestion is to break down large chunks of food into smaller pieces. Why is this important? Smaller pieces of food _____.

Answer 27

have more surface area for chemical digestion than do larger pieces of food

Question 28

In the digestive system, peristalsis is _____.

Answer 28

smooth muscle contractions that move food along the esophagus

Question 29

Which of the following is not a component of saliva?

Answer 29

proteases

Question 30

Which class(es) of large biological molecules undergo chemical digestion in the oral cavity?

Answer 30

carbohydrates