Viruses / Bacteria worksheet Answer key

Part 1: True or False

1. Viruses are considered living organisms.
2. Bacteria are smaller than viruses.
3. Viruses can replicate on their own without a host.
4. Antibiotics are effective against viruses.
5. Some bacteria are beneficial to humans.

Part 2: Fill in the Blanks

1. Viruses are made up of a ________ coat surrounding genetic material.
2. Bacteria reproduce through a process called ________ ________.
3. The study of bacteria is known as ________.
4. A virus that infects bacteria is called a ________.
5. The genetic material of a virus can be either ________ or ________.

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Part 3: Compare and Contrast

Fill in the table below with key differences between viruses and bacteria.

Feature	Viruses	Bacteria
Size
Structure
Reproduction Method
Response to Antibiotics

Part 4: Short Answer

1. Why are viruses not classified as living organisms?
2. Explain the importance of bacteria in ecosystems and human health.
3. Describe how vaccines work to prevent viral infections.

Part 5: Critical Thinking

1. You have a cold caused by a virus. Should you take antibiotics? Why or why not?
2. In what ways can bacteria become harmful, and how can we prevent bacterial infections?
3. Discuss one example of a beneficial virus or bacteria and its role.

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Part 6: Matching

Match the term to its description:

1. _____ Pathogen
2. _____ Host cell
3. _____ Binary fission
4. _____ Vaccine
5. _____ Antibiotic

A. Substance used to kill or inhibit the growth of bacteria.\
B. An organism or cell that a virus uses to replicate.\
C. A microorganism that causes disease.\
D. A preparation that stimulates an immune response.\
E. The process by which bacteria divide and reproduce.

Part 7: Multiple Choice

1. Which of the following is true about bacteria?
   A. They are always harmful.
   B. They can reproduce on their own.
   C. They cannot survive extreme environments.
   D. They require a host to replicate.
2. Which of the following is NOT a characteristic of viruses?
   A. They contain DNA or RNA.
   B. They are surrounded by a protein coat.
   C. They perform cellular respiration.
   D. They replicate using a host.
3. Which type of microorganism is used in making yogurt?
   A. Viruses
   B. Harmful bacteria
   C. Beneficial bacteria
   D. Archaea

Part 8: Case Studies

1. A patient has a sore throat caused by Streptococcus bacteria. What treatment would you recommend and why?
2. Scientists are using bacteriophages to treat antibiotic-resistant bacterial infections. Why might this be effective?
3. A community has an outbreak of influenza. Discuss how vaccination and public health measures can prevent its spread.

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ANSWER KEY

Part 1: True or False

1. False
2. False
3. False
4. False
5. True

Part 2: Fill in the Blanks

1. Viruses are made up of a protein coat surrounding genetic material.
2. Bacteria reproduce through a process called binary fission.
3. The study of bacteria is known as bacteriology.
4. A virus that infects bacteria is called a bacteriophage.
5. The genetic material of a virus can be either DNA or RNA.

Part 3: Compare and Contrast

Feature	Viruses	Bacteria
Size	Smaller than bacteria	Larger than viruses
Structure	Protein coat and genetic material	Cell wall, membrane, cytoplasm
Reproduction Method	Requires a host to replicate	Binary fission
Response to Antibiotics	Not affected	Can be killed or inhibited

Part 4: Short Answer

1. Viruses are not classified as living organisms because they cannot carry out life processes such as reproduction or metabolism without a host cell.
2. Bacteria play essential roles in ecosystems by decomposing organic material, cycling nutrients, and forming symbiotic relationships (e.g., gut bacteria aiding digestion). In human health, they produce vitamins, protect against harmful microbes, and assist in digestion.
3. Vaccines work by introducing a harmless part of a virus or bacteria, or a weakened version, to stimulate the immune system to recognize and fight the actual pathogen in the future.

Part 5: Critical Thinking

1. No, antibiotics should not be taken for a cold caused by a virus. Antibiotics target bacteria, not viruses, and their misuse can lead to antibiotic resistance.
2. Bacteria can become harmful when they invade and multiply in host tissues or release toxins. Preventing bacterial infections involves maintaining hygiene, cooking food thoroughly, and using antibiotics responsibly.
3. Example: Beneficial bacteria such as Lactobacillus help in food production (e.g., yogurt) and maintain gut health. Beneficial viruses, like bacteriophages, can be used to treat bacterial infections.

Part 6: Matching

1. C Pathogen
2. B Host cell
3. E Binary fission
4. D Vaccine
5. A Antibiotic

Part 7: Multiple Choice

1. B They can reproduce on their own.
2. C They perform cellular respiration.
3. C Beneficial bacteria

Part 8: Case Studies

1. Antibiotics should be prescribed, as Streptococcus is a bacterial infection. Ensuring proper antibiotic use prevents resistance.
2. Bacteriophages target specific bacteria, effectively killing them without harming human cells or beneficial bacteria.
3. Vaccination builds immunity against the virus, while public health measures (like mask-wearing and handwashing) reduce transmission.