Grade 6 Science – Revision Worksheet Unit 7: Microorganisms in
the Environment
PART A. Multiple Choice Questions (Choose the best answer)
1. What is a microorganism?
A. A large plant
B. A small insect
C. A living thing too small to be seen without a microscope
D. A type of mineral
2. Which of the following is single-celled?
A. Mushroom
B. Bacteria
C. Toadstool
D. Leaf
3. Which item is used to grow microorganisms in the lab?
A. Thermometer
B. Measuring tape
C. Petri dish
D. Beaker
4. Which microorganism is used in baking?
A. Algae
B. Bacteria
C. Yeast
D. Protozoa
5. Which of these is a fungus?
A. Virus
B. Yeast
C. Algae
D. Bacterium
6. What do bacteria need to grow?
A. Metal
B. Water and nutrients
C. Plastic
D. Glass
7. What is agar jelly used for?
A. Cleaning tools
B. Growing microorganisms
C. Coloring slides
D. Preserving plants
8. What is a Petri dish used for?
A. Holding soil
B. Measuring temperature
C. Growing microorganisms
D. Mixing chemicals
9. Which of these is not a microorganism?
A. Bacterium
B. Yeast
C. Mushroom
D. Virus
10. Which is true about bacteria?
A. All bacteria are harmful
B. All bacteria can be seen with the eye
C. Bacteria are everywhere
D. Bacteria are viruses
11. What is a colony?
A. A plant
B. A group of microorganisms growing together
C. A food chain
D. A lab tool
12. What do fungi feed on?
A. Light
B. Sugar only
C. Organic matter
D. Rocks
13. Where can microorganisms be found?
A. Only in water
B. Only on food
C. Everywhere
D. Only in the air
14. Which of these is a decomposer?
A. Cat
B. Plant
C. Bacteria
D. Rock
15. What causes bread to grow mold?
A. Heat
B. Water only
C. Microorganisms
D. Wind
16. What happens when microorganisms decay matter?
A. They disappear
B. They clean the air
C. Nutrients are returned to the soil
D. Plants die
17. Which microorganism is used to make bread rise?
A. Algae
B. Fungus
C. Yeast
D. Virus
18. Why should a Petri dish be sealed?
A. To stop food getting in
B. To stop bacteria escaping
C. To protect it from light
D. To prevent evaporation
19. What are protozoa?
A. Plant-like organisms
B. Animal-like microorganisms
C. Bacteria
D. Fungi
20. Which microorganism lives in pond water?
A. Yeast
B. Protozoa
C. Virus
D. Mould
21. Which microorganism can be both useful and harmful?
A. Virus
B. Yeast
C. Bacteria
D. Mushroom
22. How many cells does a bacterium have?
A. Many
B. None
C. One
D. Two
23. What is the white substance on grapes?
A. Bacteria
B. Sugar
C. Yeast
D. Fungus threads
24. Which is smaller: virus or bacteria?
A. Virus
B. Bacteria
C. Both are same size
D. Algae
25. Which microorganism group includes algae?
A. Fungi
B. Protozoa
C. Plants
D. Microorganisms
26. Why are some fungi not microorganisms?
A. They are invisible
B. They are not alive
C. They are too big to need a microscope
D. They are animals
27. Which microorganism causes athlete's foot?
A. Bacteria
B. Fungus
C. Algae
D. Virus
28. What is the function of decomposers?
A. Make food
B. Eat animals
C. Break down dead things
D. Kill plants
29. What kind of environment helps fungi grow fastest?
A. Dry and cold
B. Wet and warm
C. Hot and dry
D. Sunny and dry
30. Why do we use sterile equipment in microorganism experiments?
A. To keep the lab cold
B. To stop bacteria from spreading
C. To avoid unwanted microbes
D. To make agar jelly last longer
PART B. Fill in the Blanks
1. Microorganisms are living organisms that are too _____ to be seen without a microscope.
2. Bacteria are made of a _____ cell.
3. Fungi feed on _____ matter.
4. Yeast is a type of _____ used in baking.
5. A _____ dish is used to grow microorganisms.
6. Agar jelly must be _____ before using.
7. Mushrooms and _____ are parts of fungi.
8. Decomposers help return _____ to the soil.
9. Viruses are _____ than bacteria.
10. Fungi like _____ and warm places.
11. Yeast cells feed on _____ to grow.
12. A _____ is a group of cells growing from one microorganism.
13. Algae are plant-like microorganisms found in _____ water.
14. Bacteria can be _____ or helpful.
15. The black spots on old bread are _____.
PART C. True or False
Write "True" or "False" for each of the following statements.
1. Bacteria can be seen easily with the naked eye.
2. All fungi are microorganisms.
3. Decomposers include bacteria and fungi.
4. Agar jelly is used to feed microorganisms in a Petri dish.
5. Algae are a kind of fungus.
6. Fungi grow well in cold and dry conditions.
7. Yeast is used to make dough rise.
8. Protozoa are animal-like microorganisms.
9. Microorganisms are not important in food webs.
10. Microorganisms help decompose dead animals and plants.
11. Producers make their own food from sunlight.
12. Consumers eat other organisms to get energy.
13. Herbivores eat only meat.
14. Carnivores are always at the start of food chains.
15. A food web shows more than one food chain.
16. Energy in a food web comes originally from the Sun.
17. Decomposers return nutrients to the soil.
18. Viruses are the largest type of microorganism.
19. Yeast cells reproduce by growing buds.
20. Mould on fruit is a sign of microorganism activity.
PART D. Short Answer Questions
Answer the following questions in complete sentences.
1. Describe what a microorganism is and give two examples.
2. Explain how microorganisms can be useful in everyday life.
3. Why is it important to use sterile tools in experiments with microorganisms?
4. Describe how to grow microorganisms on agar jelly.
5. List the steps of the Petri dish experiment and its safety rules.
6. What is the role of fungi in nature?
7. Describe how a decomposer works and why it is important.
8. Explain how microorganisms affect decay.
9. Give an example of a microorganism that helps humans and explain how.
10. Why are decomposers essential to ecosystems?
11. How does energy flow in a food chain?
12. Explain the difference between a food chain and a food web.
13. Draw and label a simple food chain that includes a microorganism. (Attach your drawing
below.)
14. Draw a food web that includes at least 5 organisms and one decomposer. (Attach your
drawing below.)
15. What safety measures must be taken when working with microorganisms in class?
