TEST DATE: __________
NAME:
Regents Biology
Homework Packet
Unit 11: Nutrition and Digestion

Use your Biology by Miller & Levine textbook to complete and help with the following homework
assignments.

(1) Read the assigned pages, (2) Define the vocabulary, and (3) Answer the questions.

Neatness counts. Number the definitions. Write the page and number of the questions. Do your work in
ink or even type the homework. Staple the definitions and questions to the HW packet.

The homework assignment is due the day before the test. We will use the HW packet as a test review.
The completed and corrected HW packet will be collected on the day of the test. Late homework
assignments receive no credit (0). If the assignment is not turned in by the last day of the quarter the
zero grade (0) will change to -5.
Ch 30: Digestive and Excretory Systems
Read pgs. 860 – 881; 889 – 893
Vocabulary
p. 862 (6)
p. 868 (6)
p. 875 (11)
p. 867 #2a, 2b
p. 873 #1a, 2a, 2b
p. 881 #1b, 2a, 3a, 3b, 4
Regents Review
891 – 893
#1, 3, 5, 6, 8, 10 – 20, 23 – 25
Food Irradiation
For months, Jill and Laura had been planning their camping trip to a remote
region of South America. It was going to be a serious trip - everything they might
need for the entire four weeks would be carried by them in backpacks. They chose
their equipment carefully, picking out just the right tent, clothes, shoes, and
cooking equipment. But, by far the most preparation went into selecting the food
they would bring. "We must make sure our meals are well balanced," said Laura.
"We need to include food from each of the major food groups."
After numerous trips to supermarkets, camping stores, and health food stores, Jill and Laura realized
that it was not easy to find nutritious food that would not spoil without refrigeration.
"l guess we just can't have fresh fruits, vegetables, meats, and dairy products during our trip," Jill said.
"Wouldn't it be great if there was a way to treat these foods so they wouldn't spoil so quickly?"
"Yes," replied Laura, "l hear there actually is a method that may accomplish just that. Some scientists
are now experimenting with a process known as irradiation, which they say increases the shelf life of many
products. But, others are very skeptical about it because they feel it may introduce dangerous new substances
into the food."
The Food Irradiation Process
In the 1940s, the United States Army began experimenting
with food irradiation as a possible solution to the problem of
feeding its troops in the field. Interest in this new process grew
rapidly. These early studies showed that irradiation was an
effective, economical, and relatively simple process to perform.
To irradiate a food, the food is placed inside a closed
chamber containing radioactive forms of the elements cesium
and cobalt. These elements emit radioactive gamma rays, most of
which pass through the food. Some of the rays are absorbed by
the food. It is this absorbed energy that slows down the aging
process and kills insects and some microorganisms present in the
food.
A Proposed Food Irradiation Unit. Boxed food
would move through a chamber enclosed by
thick concrete walls. Inside the chamber, food
would be exposed to cobalt'60 or cesium-137.
The amount of radiation a food receives is determined by the amount of time the food is exposed to
the radioactive elements. High levels of radiation will preserve some foods indefinitely; somewhat lower levels
will make it possible to keep items such as meats and poultry unrefrigerated for weeks. It is the role of the
Food and Drug Administration (FDA) to determine if irradiated food is safe for human consumption, and if so,
at what levels.
The FDA decided that irradiation is a safe process after about thirty years of research. Thus far, it has
approved irradiation of pork, fruits, vegetables, spices, teas, wheat and white flour, and white potatoes. A
major finding of the FDA's research was that this treatment does not make foods radioactive. But those who
oppose food irradiation claim this does not mean the food is safe. They are concerned about the chemical
changes that take place in food as a result of irradiation.
Scientists have identified various chemical substances that form in foods upon irradiation. Many of
these substances, called radiolytic products (RPs), now are known to exist also in foods that have been
canned, frozen, or dehydrated. While RPs are not believed to be harmful and some RPs are found in untreated
or cooled foods, irradiated foods contain some RPs that are not seen elsewhere. More than 40 of these
substances, which are known as Unique Radiolytic Products (URPs), have been found in irradiated foods thus
far. Many scientists claim that these URPs, like RPs, are not new substances. Other scientists are worried that
we know nothing about URPs, especially what effects they might have on humans who consume them over
long periods of time. They fear that URPs may trigger the development of cancer by damaging the body's
chromosomes
Scientific Studies
The FDA has evaluated hundreds of animal studies on food irradiation. In one extensive study done by
the U.S. Department of Agriculture, 300,000 pounds of irradiated chicken was fed to mice, rats, rabbits, and
beagles over a period of two years. The study evaluated effects on birth, reproduction, and the production of
toxic substances. It concluded that irradiation was a safe process.
Other scientific studies have led to very different conclusions. When ten human subjects were fed
irradiated wheat, some cells in their bodies developed abnormally. This condition gradually reversed itself
when this diet was stopped. Studies done on mice showed that groups fed irradiated foods had a higher death
rate and a higher incidence of tumors than did control groups. Fruit flies that were fed irradiated chicken
produced fewer offspring than the controls.
The FDA admits that the studies done so far have not been perfect. As one agency representative
remarked, "On the whole, you can find something wrong with every one of them." But, as the FDA also points
out, better studies are just not possible. In traditional animal feeding studies, high levels of the additive in
question are added to the food in order to exaggerate its effects. But with irradiation, the food and the
additive are essentially one and the same. To increase the amount, the animal would either have to be fed
more food than it ordinarily consumes or the dose of radiation would have to be increased so much that the
food's nutritional content would be destroyed.
Some scientists feel that animal studies, are simply not sufficient to resolve safety concerns. It is their
view that human epidemiological studies should be done. But as one scientist noted "Such a study is unlikely
to be done because it would require controlling the diets of at least 200,000 humans of various age groups for
at least 30 years, and following their health histories for at least 50 years." Without such a study, the FDA has
based its decisions on the studies that have been done.
Benefits of Food Irradiation
Those who favor food irradiation say it is the most important advance in dietary health since the
invention of pasteurization. Because currently 25 to 30 percent of the world's food supply is lost to spoilage
and pests, irradiation can help to fight global hunger. As of today, about twenty countries including Canada,
Japan, and the Netherlands allow the irradiation of a wide variety of foodstuffs.
The use of irradiation in the United States might enable us to expand the number of agricultural
products we export. Perishable foods could be shipped further distances without the risk of spoilage. By
providing more markets for their crops, irradiation might help alleviate many of the economic problems facing
the country's farmers today. At the same time, irradiation might make possible the exporting of perishable
foods to countries in need of them.
Another advantage of irradiation is its ability to protect human health by killing parasites like
salmonella, a bacterium that causes food poisoning, and the trichina worm in pork. It is believed that
trichinosis will soon be eradicated in the U.S. through the use of irradiation. In addition, food irradiation may
offer a safe alternative to many chemical pesticides, fumigants, and preservatives that are applied to stored
grains and fruits. One popular pesticide, ethylene dibromide (EDB), was banned recently by the FDA after it
was found to be carcinogenic. A few days after the ban on EDB, the Department of Health and Human Services
(which oversees the FDA) approved the use of low-dose radiation in its place.
Food irradiation also might provide a use for nuclear wastes. One of the byproducts of nuclear fuel
processing is radioactive cesium; currently, the disposal of nuclear wastes poses a major safety problem for
the world. By making use of this radioactive element in food processing, the risks and costs of nuclear wastes
disposal would be greatly reduced.
Drawbacks to Food Irradiation
There are many people who feel that the benefits of food irradiation do not outweigh its drawbacks.
Aside from the production of radiolytic products, they claim that irradiation alters the appearance, flavor,
texture, and nutritive value of many foods. Some nutritionists have noted that exposure to irradiation gives
milk a bad taste and causes soft foods, such as citrus fruits, to become mushy. In addition, they believe that
irradiation alters some amino acids and fats and destroys several vitamins, including A, some of the B group, C,
and E.
While irradiation may destroy many harmful pests, Clostridium botulinum (the bacterium responsible
for botulism) and aflatoxin (a poisonous substance produced by fungi) are resistant to irradiation. Some
scientists fear that if most of the organisms in a food sample are destroyed, the lack of microbial competition
might enable these resistant organisms to thrive. Alternatively, irradiation may produce dangerous variations
in some microorganisms, which then could be released into the environment.
Irradiation may not be the only alternative to many
pesticides, fumigants, and preservatives. Scientists currently are
testing aluminum phosphide, diatomaceous earth, and cold
storage of fruits as possible insecticides. In order to utilize nuclear
wastes in food irradiation, the wastes would have to be
transported great distances to and from irradiating facilities,
which are scheduled to be located in cities and farmlands. This
would greatly increase the risk of worker and public exposure to
these radioactive materials.
Logo to be Used to Indicate that Food Has
Been Irradiated.
Public Acceptance
Even if food irradiation gains widespread approval by the FDA, public acceptance of the process may
lag far behind. Supermarkets have the go-ahead to sell irradiated fruits and vegetables, but few have these
items on their shelves. More than 50 percent of people surveyed would not even try irradiated meats, poultry,
or seafood. When the respondents were asked for their reasons, they voiced fears of exposure to radiation. As
one person explained, "Radiation is a scary word." The food industry has set public education as one of its
immediate goals. Industry representatives hope to prove to the public that this process is as safe as freezing
and canning.
1. What is food irradiation?
2. How are foods irradiated?
3. Why does irradiation extend the shelf life of some foods?
4. Why are some people concerned about the radiolytic products that form upon irradiation?
5. The essay states that when 300,000 pounds of chicken were fed to a large number of mice, rats, rabbits,
and beagles, it was determined that food irradiation was safe for humans. However, when 10 human subjects
were fed irradiated wheat, the opposite conclusion was reached. Which of these studies do you think was
more valid? Explain your reasoning.
6. Even though they have not yet been studied, the safety of Unique Radiolytic Products (URPs) found in
irradiated foods is assumed by some scientists. This is because other radiolytic products have been found to
be safe. Is this conclusion valid? How certain can the scientists be?
7. Has your food been irradiated? Research which are the most likely foods you have been eating that have
possibly been irradiated.
Adaptations for Digestion
Organism:
Organism:
Organism:
Distinctive digestive
feature(s):
Distinctive digestive
feature(s):
Organism:
Organism:
Distinctive digestive
feature(s):
Distinctive digestive
feature(s):
Distinctive digestive
feature(s):
Know the Terms
Match the definition to the word. Some words have more than one definition.
a. Produces gastric juice
g. Produces bile
b. The end of the digestive system
h. Solid wastes
c. Emulsifies lipids
i. Connects pharynx to stomach
d. Digests carbohydrates in the
mouth
j. Absorbs water
k. Eliminates wastes
n. Grinds food, temporarily stores
food, and adds gastric juice
o. Part of the lymphatic system that
absorbs the
end products of lipid
digestion.
p. Fingerlike projections in small
intestine that absorbs nutrients
e. Lower part of large intestine
f. A measure of heat energy
l. Stores wastes
m. Finishes digestion and absorbs
nutrients
q. Digestive enzyme found in gastric
juice
___ 1. amylase
___ 6. feces
___ 11. pepsin
___ 2. anus
___ 7. lacteal
___ 12. rectum
___ 3. bile
___ 8. large intestine
___ 13. small intestine
___ 4. calorie
___ 9. liver
___ 14. stomach
___ 5. esophagus
___ 10. mouth
___ 15. villi
Understand the Concepts
1. Types of Nutrition
There are two basic ways that organisms obtain the organic nutrients they need. Some organisms are
capable of making, or synthesizing, these nutrients from simple inorganic substances. Such organisms are
autotrophs (atr:t-uh-trohfs). Green plants and green algae and various other types of microorganisms are
autotrophs. Most autotrophs are photosynthetic that is, they use energy from sunlight, and carbon dioxide and
water from the environment to make their own organic nutrients. These organisms are called phototrophs.
However, certain types of bacteria that are autotrophs do not use light as a source of energy. They are
chemosynthetic, i.e., they obtain energy from special types of chemical reactions. Such organisms are called
chemotrophs (kee-muh-trohfs).
Heterotrophs (het-uh-ruh-trohfs) are organisms that cannot synthesize their own organic nutrients. All
animals and certain types of microorganisms are heterotrophs. Such organisms must take in, or ingest, food
containing "ready-made" nutrients from other plants or animals.
Define:
a. autotroph:
b. chemotroph:
c. heterotroph:
d. What is the difference between an autotroph and a heterotroph?
e. What is the relationship between autotrophs and heterotrophs?
2. Digestion
For a nutrient to be used by the cells of an organism, it must pass through the cell membranes. In
general, the nutrient molecules in food are too large to pass through cell membranes. Thus, to be used by the
cells, most food molecules must be broken down into smaller, simpler forms. The process by which food
molecules are broken down is called digestion (dyjes-chun).
The term digestion usually refers to the chemical breakdown of food substances into simple
compounds. In many organisms, pieces of food are first cut, crushed, or broken into smaller particles without
being changed chemically. This treatment results in the mechanical breakdown of the food. Mechanical
breakdown increases the surface area of the food particles. Chemical digestion is carried out by digestive
enzymes, which act only on the surface of food particles. Thus, mechanical breakdown prepares the food for
more rapid chemical digestion by exposing more food surface to the action of the digestive enzymes. Chemical
digestion, like mechanical breakdown, takes place in stages. Large molecules are broken down into smaller
molecules, and these in turn are broken down into still simpler forms. The usable, simplest products of
digestion are the end products of digestion
a. Define digestion:
b. What are the end products of digestion?
3. Trace the path of food through the alimentary canal of the grasshopper.
4. Why are nutrients needed by the body?
5. Where does digestion take place in protozoa?
6. List the human accessory glands, what each produces, and what the product does to food.
GLAND
PRODUCT
EFFECT
7. How is a large surface area important in digestion and absorption?
8. What nutrients are required by living organisms? List them as organic and inorganic.
Large Intestine
Gall Bladder
Liver
Pancreas
Small Intestine
Stomach
Esophagus
Mouth
Name
Structure
Parts
Function
Human Digestive System
Enzymes / Chemicals
Digestive Chemicals
Chemical/ Enzyme
Salivary Amylase
Pepsin
Trypsin
Amylase
Lipase
Nuclease
Bile
Organ Made / Used
Digestion
Digestive System Disorders
Disorder
Ulcer
Gall Stones
Diarrhea
Constipation
Appendicitis
Anorexia
Bulimia
Acid Reflux
Description of
Problem
Organ(s) affected
Disruption of Homeostasis
Choose the best answer and write it on the blank.
Use the choices for questions 1 -5.
1. digestion
2. pepsin
3. peristalsis
4. heterotroph
___ 1. digestive enzyme in gastric juice
___ 2. alternate waves of relaxation and contraction in the walls of the alimentary canal
___ 3. organism that cannot synthesize its own organic nutrients
___ 4. substance that breaks down large protein molecules into polypeptides
___ 5. process by which food molecules are broken down
___ 6. Organisms that use carbon dioxide and water from the
environment and energy from sunlight to make their own
organic nutrients are called
1. phototrophs
2. chemotrophs
3. bacteria
4. heterotrophs
___ 7. A major difference in the digestive systems of the
earthworm and the grasshopper is that
1. only the earthworm has a tubular digestive system
2. both have a crop but only the earthworm has a gizzard
3. only the grasshopper has salivary glands
4. only the grasshopper digests food mechanically
___ 8. A major difference in digestion between the hydra and
the earthworm is that 13.
1. the hydra is an autotroph and the earthworm is a heterotroph 2. wastes pass out the hydra's mouth and the earthworm's anus
3. only the hydra has an alimentary canal
4. the earthworm can ingest food only after previous food has
been digested
Use the diagram to answer questions 9 -12.
___ 9. The sequence of food passing through the digestive
system is
1. 2, 1, 3, 5, 9, 6, 7
2. 1, 3, 5, 9, 6, 7
3. 1, 3, 4, 9, 6, 7
4. 1, 3, 5, 6, 9, 7
___ 10. In which of the following does water reabsorption
occur?
1. 3
2. 8
3. 5
4. 9
___ 11. In which of the following does mechanical digestion
occur?
1. 1, 2, and 11 only
2. 1, 3, and 5 only
3. 3, 9, and 10 only
4. 4, 5, and 6 only
___ 12. Which organ produces lipase?
1. 8
2. 5
3. 3
4. 4
___ 13. The amount of energy needed to raise the temperature
of one gram of water 1’C is
1. 1’C
2. 1 calorie
3. 1 gram
4. 1 kilocalorie
___ 14. The human epiglottis
1. closes during swallowing
2. closes during breathing
3. prevents food from passing through the esophagus
4. allows food to pass through the windpipe
___ 15 Which of the following are coenzymes that participate
with enzymes to catalyze reactions?
1. acids
2. mucus
3. vitamins
4. amylases
___ 16. Which life process is classified as autotrophic in some
organisms and heterotrophic in other organisms?
1. hormonal regulation
2. nutrition
3. anaerobic respiration 4. transport
___ 17. The diagram shown represents the cross section of an
earthworm. Which letter indicates a structure that provides an
increased surface area for the absorption of digestive end
products?
___ 22. Which structure indicated in the diagram of a
paramecium is used for the process of egestion?
1. A
1. A
2. B
3. C
4. D
___ 18. What does the process of photosynthesis produce?
1. starch, which is metabolized into less complex molecules by
dehydration synthesis
2. protein, which is metabolized into less complex molecules by
dehydration synthesis
3. glycerol, which is metabolized into more complex
carbohydrates by dehydration synthesis
4. glucose, which is metabolized into more complex
carbohydrates by dehydration synthesis
___ 19. Which statement correctly describes one characteristic
of the tube-like digestive system of an earthworm?
1. Various parts of the system perform different digestive
functions.
2. The shape of the system allows food to be processed by
intracellular digestion.
3. The shape of the system eliminates the need for egestion.
4. Digestive enzymes are not used in the system.
2. B
3. C
___ 23. Which structures are adaptations for nutrition in the
paramecium?
1. pseudopodia and food vacuoles
2. oral groove and cilia
3. flagellum and eyespot
4. contractile vacuoles and oral groove
___ 24. Two demonstrations were performed as described
below. The two demonstrations were most likely used to
illustrate the difference between
1. chemical and mechanical digestion
2. photosynthesis and hydrolysis
3. chemical digestion and hydrolysis
4. mechanical digestion and synthesis
___ 25. The diagram below represents a protist. Structure X is
most directly involved in the process of
___ 20. Which activity is illustrated in the diagram of an
ameba?
1. egestion
3. respiration
2. synthesis
4. ingestion
___ 21. A fungus is classified as a heterotroph rather than an
autotroph because it
1. grows by mitosis
2. absorbs food from the environment
3. manufactures its own food
4. transforms light energy into chemical energy
4. D
1. extracellular digestion 2. enzymatic hydrolysis
3. ingestion
4. transpiration
___ 26. The series of diagrams shown represents a process
carried out by a unicellular organism.
This process is known as
1. autotrophic nutrition
3. sporulation
___ 33. Which three processes are indicated by the arrows in the
accompanying diagram?
2. replication
4. phagocytosis
___ 27. Because mushrooms absorb nutrients from decaying
leaves, they are classified as
1. autotrophs
2. anaerobes
3. heterotrophs
4. protozoans
___ 28. The gizzard of an earthworm performs a digestive
function similar to that of the
1. small intestine in a human
2. crop in a grasshopper
3. anal pore of a paramecium
4. teeth of a cow
___ 29. The function of the gastric caecum in a grasshopper is
most similar to the function of the
1. nephridium in an earthworm
2. pancreas in a human
3. anal pore in a paramecium
4. nerve net in a hydra
1. ingestion, diffusion, and excretion
2. ingestion, digestion, and egestion
3. cyclosis, meiosis, and mitosis
4. diffusion, active transport, and cyclosis
Use the diagram to answer questions 34 – 36.
___ 30. Which two organisms represented are heterotrophic?
1. A and B
3. C and E
2. B and C
4. D and E
___ 31. Which chemical reaction is represented by the diagram?
___ 34. From which structure are glucose and amino acids
normally absorbed into the circulatory system?
1. F
2. H
3. C
4. E
___ 35. In which structure does extracellular chemical digestion
of protein begin?
1. G
2. B
3. C
4. E
1. dehydration synthesis of a dipeptide
2. hydrolysis of a polypeptide
3. dehydration synthesis of a lipid
4. hydrolysis of a disaccharide
___ 32. Which food would provide the most roughage for the
body?
1. baked fresh fish
2. lettuce-and-tomato salad
3. fried chicken breast
4. milk shake
___ 36. In which structure does the initial hydrolysis of
carbohydrates occur?
1. A
2. E
3. C
4. D
___ 37. Which substance is a nutrient in the human diet?
1. oxygen
2. carbon dioxide
3. water
4. roughage
___ 38. After food enters the small intestine, lipases, proteases,
and amylases are secreted into the small intestine by the
1. liver
2. gallbladder
3. salivary glands
4. pancreas
___ 39. In some regions of the world, children suffer from a
protein deficiency known as kwashiorkor. This deficiency
occurs when a child's diet is changed from high-protein breast
milk to watery cereal. Even though the child is receiving
calories, the child becomes sick and less active, and growth
ceases. These symptoms are probably due to
1. too many nucleic acids in the diet
2. an overconsumption of complete protein foods
3. not enough carbohydrates in the diet
4. a lack of essential amino acids in the diet
___ 43. Which structures secrete chemicals utilized for the
completion of digestion within the small intestine?
1. liver and pancreas
2. glomerulus and villi
3. esophagus and alveoli
4. gallbladder and pharynx
Base your answers to questions 44 - 47 on the diagrams and on
your knowledge of biology. The diagrams illustrate the pathway
and the time frame for the digestion of a hamburger consisting
of ground beef, ketchup, and a whole-wheat bun.
___ 40. In humans, chemical digestion is accomplished by
enzyme action that begins in the mouth and ends in the
1. esophagus
2. stomach
3. small intestine 4. gallbladder
___ 41. The graph shows the concentration of sugar (glucose) in
the blood of a human over a 24-hour period after an injection of
insulin. Which conclusion could be supported by these data?
1. Blood sugar concentration rises after the body uses up the
injected insulin.
2. Insulin raises blood sugar concentration in the liver.
3. Blood sugar concentration remained constant in the blood
throughout the 24-hour period.
4. Insulin lowers blood sugar concentration in the muscle cells.
___ 42. The diagram shows a particle of food being moved
along the human digestive tract by alternate waves of relaxation
and contraction of the muscular walls of the esophagus. Which
process causes the movement of the food down the esophagus?
___ 44. An irritant can cause an erosion in the lining of structure
C, leading to a disorder known as
1. constipation
2. ulcers
3. gout
4. appendicitis
___ 45. Chemical digestion of the whole-wheat bun begins after
hydrolytic enzymes are secreted by structure
1. A
2. B
3. C
4. D
___ 46. During which period does most of the digestive action
of bile and pancreatic juice occur?
1. 6:03 p.m. to 6:05 p.m.
2. 6:05 p.m. to 6:08 p.m.
3. 10:15 p.m. to 9:50 a.m.
4. 9:50 a.m. to 1:00 p.m.
___ 47. Hydrolysis of the proteins present in the ground beef
usually takes place in structures
1. A and E
2. B and C
3. C and D
4. A and D
1. circulation
3. peristalsis
2. active transport
4. osmosis
___ 48. An accumulation of hardened cholesterol deposits is
associated with the development of
1. gout
2. gallstones
3. constipation
4. appendicitis
___ 49. Which substance is normally absorbed by the large
intestine?
1. water
2. glycogen
3. protein
4. cellulose
___ 50. Which type of digestion occurs in the mouth when an
individual chews a piece of bread?
1. mechanical digestion, only
2. chemical digestion, only
3. both mechanical and chemical digestion
4. neither mechanical nor chemical digestion