New World American PVT School
‫مدرسة العالم الجديد األمريكية الخاصة‬
Name:.......................................................................................... Grade: 10
Section: .......... Date:...................................
Subject: Biology
Topic: Beneficial Roles of Prokaryotes.
I
Q1. Fill in the diagram below with the ways bacteria benefit from an animal host and the
ways a host can benefit from resident bacteria.
Bacteria receive:
1. ____________
2. ____________
3. ____________
Host receives:
4. ____________
5. ____________
bacteria
Mutualistic
symbiosis
host
6. ____________
Q2. Fill in the blanks in the chart with details about some of the roles prokaryotes play in
an ecosystem.
Role
Details
1. Atmosphere composition
Some prokaryotes, such as __________, produce
______________ through photosynthesis.
2. Element cycling
Bacteria help to recycle elements through the
ecosystem. Elements cycled by bacteria include:
_____________, nitrogen, hydrogen, and
___________.
3. Nitrogen fixation
Some cyanobacteria and other bacteria can convert
_____________ from the atmosphere into
______________ and other compounds that plants
can use.
Q3. Answer the following.
1. What are three ways we benefit by having prokaryotes living in our digestive tracts?
_________________________________________________________________
2. Why do you think that we do not get sick from eating foods such as yogurt that often contain
live bacteria cultures?
_________________________________________________________________
3. What are three important roles that prokaryotes play in an ecosystem?
_________________________________________________________________
4. What are two ways that prokaryotes help relieve pollution?
_________________________________________________________________
_________________________________________________________________
New World American PVT School
‫مدرسة العالم الجديد األمريكية الخاصة‬
Name:.......................................................................................... Grade: 10
Section: .......... Date:...................................
Subject: Biology
Topic: Beneficial Roles of Prokaryotes.
II
Q4. Choose the letter of the best answer.
1. Like photosynthetic plants, cyanobacteria produce
a. nodules.
b. nitrogen.
c. oxygen.
d. cyanide.
2. When microbes are applied to pollutants in order to break them down, the process is called
a. recycling.
b. fermentation.
c. photosynthesis. d. bioremediation.
3. How do bacteria benefit from living in a human digestive system?
a. They adapt to fluctuations in temperature.
b. They get food and a place to live.
c. They receive the vitamins they need.
d. They make nitrogen that they can use.
4. Bacteria impart flavor to cheese through the process of
a. vitamin production.
b. nitrogen fixation.
c. fermentation.
d. bioremediation.
5. Legumes have a mutualistic relationship with bacteria that live in
a. human intestines.
b. their root nodules.
c. air trapped in the soil.
d. ammonia.
6. Peas, beans, and other legumes have a mutualistic relationship with bacteria. Where do the
bacteria associated with these plants live?
a. in the plant’s leaves
b. in the plant’s stem
c. in the plant’s root nodules
d. in the plant’s chloroplasts
7. How do bacteria associated with legumes provide nitrogen to the plant in a usable form?
a. They use it in a chemical reaction, producing ammonia.
b. They make it into air bubbles and release it.
c. They dissolve it in water.
d. They get it from sunlight.
8. Some bacteria can digest oil. How are these bacteria helpful?
a. They can prevent the surface of a plant from being covered with natural oils.
b. They can be used to bioremediate oil spills at sea and on beaches.
c. They can be used to mine for oil and bring it to the surface more easily.
d. They can reduce the amount of oil that is normally present in the environment.
9. What does the term biodegradable mean?
a. If you leave it in nature, it will be there forever without decomposing.
b. If you leave it in nature, it will quickly rot due to the action of bacteria.
c. If you leave it in nature, it will remain sterile and will not be colonized by bacteria.
d. If you leave it in nature, it will eventually be scavenged by living things for their
own purposes.
New World American PVT School
‫مدرسة العالم الجديد األمريكية الخاصة‬
Name:.......................................................................................... Grade: 10
Section: .......... Date:...................................
Subject: Biology
Topic: Beneficial Roles of Prokaryotes.
III
Q5. Answer the following questions with proper reasoning.
1.Some prokaryotes live in animal digestive systems. What are three ways these prokaryotes are
helpful to the animals they live inside?
_________________________________________________________________
_________________________________________________________________
2. What are two ways animals help the prokaryotes that live in their digestive tracts?
_________________________________________________________________
3. What are examples of types of food we eat that are fermented by bacteria?
_______________________________________________________________
4. Peas, beans, and other legumes have a mutualistic relationship with bacteria. Where do the
bacteria associated with these plants live?
_________________________________________________________________
_________________________________________________________________
5. The bacteria associated with legumes provide nitrogen to the plant in a usable form. Describe
how they do this.
_________________________________________________________________
_________________________________________________________________
6. Some bacteria can digest oil. How are these bacteria helpful?
_________________________________________________________________
_________________________________________________________________
7. What does the term biodegradable mean?
_________________________________________________________________
8. What is a type of human-made material that is not biodegradable?
_________________________________________________________________