← Back to chapter
Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Microorganisms and Disease — Practice Worksheet
Chapter: Microorganisms and Disease
Topic: Microorganisms and Disease
Maximum Marks: 35
Time: 30 minutes
Name: ____________________ Roll No.: __________ Date: ____________

General Instructions

  • All questions are compulsory.
  • Choose the correct option (A, B, C or D) for each question.
  • The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each) 35 × 1 = 35 marks
1.
Microorganisms can be seen only with the help of a:
  • A.Telescope
  • B.Microscope
  • C.Magnifying mirror
  • D.Naked eye
2.
Which microorganism can reproduce only inside a living host cell?
  • A.Bacteria
  • B.Virus
  • C.Fungi
  • D.Algae
3.
Which group of microbes makes its own food by photosynthesis?
  • A.Algae
  • B.Protozoa
  • C.Bacteria
  • D.Viruses
4.
Amoeba and Paramecium are examples of:
  • A.Fungi
  • B.Algae
  • C.Protozoa
  • D.Viruses
5.
The fuzzy growth on stale bread is a:
  • A.Bacterium
  • B.Fungus
  • C.Virus
  • D.Protozoan
6.
The bacterium that fixes nitrogen in legume root nodules is:
  • A.Lactobacillus
  • B.Rhizobium
  • C.Yeast
  • D.Plasmodium
7.
Milk is converted into curd by:
  • A.Yeast
  • B.Algae
  • C.Lactobacillus
  • D.Virus
8.
Yeast makes bread rise by releasing the gas:
  • A.Oxygen
  • B.Nitrogen
  • C.Carbon dioxide
  • D.Hydrogen
9.
Penicillin, an antibiotic, is obtained from a:
  • A.Virus
  • B.Fungus
  • C.Protozoan
  • D.Alga
10.
Microbes that break down dead matter and recycle nutrients are called:
  • A.Producers
  • B.Decomposers
  • C.Predators
  • D.Vectors
11.
A disease-causing microorganism is called a:
  • A.Decomposer
  • B.Pathogen
  • C.Producer
  • D.Host
12.
Which disease is caused by a protozoan?
  • A.Tuberculosis
  • B.Cholera
  • C.Malaria
  • D.Typhoid
13.
Rust of wheat, a plant disease, is caused by a:
  • A.Virus
  • B.Fungus
  • C.Protozoan
  • D.Alga
14.
Eating spoiled food can cause food poisoning because microbes release:
  • A.Oxygen
  • B.Toxins
  • C.Vitamins
  • D.Minerals
15.
The common cold and influenza in humans are caused by:
  • A.Bacteria
  • B.Viruses
  • C.Fungi
  • D.Algae
16.
A disease that spreads from an infected person to a healthy one is called:
  • A.Non-communicable
  • B.Communicable
  • C.Deficiency
  • D.Hereditary
17.
Tuberculosis mainly spreads through:
  • A.Water
  • B.Air
  • C.Soil
  • D.Touch only
18.
Cholera and typhoid are commonly spread through:
  • A.Contaminated water
  • B.Magnets
  • C.Sunlight
  • D.Dry air
19.
The vector that spreads malaria is the:
  • A.Housefly
  • B.Anopheles mosquito
  • C.Cockroach
  • D.Honeybee
20.
Which is a good way to prevent water-borne diseases?
  • A.Drink unfiltered pond water
  • B.Boil drinking water
  • C.Leave food uncovered
  • D.Skip washing hands
21.
The body's defence network against microbes is the:
  • A.Digestive system
  • B.Immune system
  • C.Nervous system
  • D.Skeletal system
22.
Which is part of innate (inborn), non-specific immunity?
  • A.Skin barrier
  • B.A specific antibody
  • C.Memory cell
  • D.A vaccine
23.
A foreign substance that triggers an immune response is a/an:
  • A.Antibody
  • B.Antigen
  • C.Vaccine
  • D.Vector
24.
Proteins that lock onto a specific microbe to neutralise it are:
  • A.Antigens
  • B.Antibodies
  • C.Toxins
  • D.Enzymes only
25.
A vaccine protects us by making the body produce antibodies and:
  • A.Toxins
  • B.Memory cells
  • C.Mucus
  • D.Stomach acid
26.
Antibiotics are medicines used to fight diseases caused by:
  • A.Viruses
  • B.Bacteria
  • C.Vitamins
  • D.Allergies
27.
The first antibiotic, penicillin, was discovered by:
  • A.Edward Jenner
  • B.Alexander Fleming
  • C.Louis Pasteur
  • D.Robert Koch
28.
Penicillin is produced by a:
  • A.Bacterium
  • B.Fungus (Penicillium)
  • C.Virus
  • D.Protozoan
29.
Taking antibiotics for a viral cold is useless because antibiotics:
  • A.Are too strong
  • B.Do not work on viruses
  • C.Cause fever
  • D.Work only outside the body
30.
Overuse and misuse of antibiotics leads to:
  • A.Faster cure always
  • B.Antibiotic resistance (AMR)
  • C.More vitamins
  • D.Stronger immunity
31.
Food preservation mainly works by stopping the growth of:
  • A.Plants
  • B.Microbes
  • C.Insects only
  • D.Minerals
32.
Milk is made safe and longer-lasting by heating and quick cooling, a method called:
  • A.Pickling
  • B.Pasteurisation
  • C.Canning
  • D.Irradiation
33.
Refrigeration preserves food by:
  • A.Killing all microbes instantly
  • B.Slowing microbe growth with cold
  • C.Adding salt
  • D.Removing air
34.
Drying food (dehydration) preserves it because microbes cannot grow without:
  • A.Light
  • B.Water (moisture)
  • C.Salt
  • D.Sugar
35.
Sealing heated food in airtight tins for long storage is called:
  • A.Canning
  • B.Pickling
  • C.Refrigeration
  • D.Pasteurisation

Answer Key

Section A — Multiple Choice (1 mark each)
  1. (B) Microscope
  2. (B) Virus
  3. (A) Algae
  4. (C) Protozoa
  5. (B) Fungus
  6. (B) Rhizobium
  7. (C) Lactobacillus
  8. (C) Carbon dioxide
  9. (B) Fungus
  10. (B) Decomposers
  11. (B) Pathogen
  12. (C) Malaria
  13. (B) Fungus
  14. (B) Toxins
  15. (B) Viruses
  16. (B) Communicable
  17. (B) Air
  18. (A) Contaminated water
  19. (B) Anopheles mosquito
  20. (B) Boil drinking water
  21. (B) Immune system
  22. (A) Skin barrier
  23. (B) Antigen
  24. (B) Antibodies
  25. (B) Memory cells
  26. (B) Bacteria
  27. (B) Alexander Fleming
  28. (B) Fungus (Penicillium)
  29. (B) Do not work on viruses
  30. (B) Antibiotic resistance (AMR)
  31. (B) Microbes
  32. (B) Pasteurisation
  33. (B) Slowing microbe growth with cold
  34. (B) Water (moisture)
  35. (A) Canning
Generated by Vidaara.org · Assignment VID-M8-WS · vidaara.org