Virus and Bacteria Worksheet | PDF - Free Printable
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Step-by-step solution for: Virus and Bacteria Worksheet | PDF
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Step-by-step solution for: Virus and Bacteria Worksheet | PDF
It looks like you've uploaded a worksheet titled "Viruses and Bacteria Worksheet", but the image is not fully visible or clear enough to extract all the questions and answers directly. However, based on the visible portion of the worksheet, I can help you solve and explain the problems that are partially visible.
Let’s go through what we can see and provide accurate answers with explanations:
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- Answer: A virus is made of nucleic acid (DNA or RNA) surrounded by a protein coat (capsid). Some viruses also have an outer envelope.
- What it does NOT have: Viruses do not have cellular structures like ribosomes, cytoplasm, or organelles. They also lack metabolic machinery and cannot reproduce on their own.
> 🔍 *Explanation*: Viruses are acellular—meaning they are not cells. They rely entirely on host cells to replicate.
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- Answer: No, viruses do not belong to any kingdom.
- Reason: Viruses are not considered living organisms because they lack key characteristics of life such as metabolism, growth, and independent reproduction.
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- Answer: Viruses need a host cell to replicate and carry out their life cycle.
- Explanation: They are obligate intracellular parasites—they must infect a living cell to reproduce.
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- Answer: Retroviruses (if they reverse transcribe RNA into DNA) or more generally, RNA viruses.
- Note: Not all RNA viruses are retroviruses. For example, influenza is an RNA virus but not a retrovirus.
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- Name of virus that attacks bacteria: Bacteriophage (e.g., T4 phage)
- Virus that causes "Mad Cow Disease": Prion (but note: prions are not viruses; they are misfolded proteins). The actual cause of Mad Cow disease is a prion, not a virus.
- However, if the question expects a virus, it might be a trick—no virus causes Mad Cow disease. It's caused by prions.
- But if it's asking for a viral disease in cows, then Bovine Viral Diarrhea Virus (BVDV) could be an example.
> 🚨 Clarification: "Mad Cow Disease" = Bovine Spongiform Encephalopathy (BSE) → caused by prions, not viruses.
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Assuming the diagram shows the viral replication cycle (e.g., lytic cycle):
| Step | Description | Letter |
|------|-------------|--------|
| 8. | Host nuclear acid is injected into host cell | A |
| 9. | The virus’ nucleic acid is copied | B |
| 10. | The host cell explodes, releasing C | C |
| 11. | The virus attaches itself to the host cell | D |
| 12. | Cell reproduces more viruses | E |
> 🔎 *Explanation*:
> - D: Attachment
> - A: Penetration (injection of genetic material)
> - B: Replication of viral genome
> - E: Assembly of new viruses
> - C: Release (lysis)
This follows the lytic cycle of a bacteriophage.
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#### 23. Kingdoms of true bacteria
- Answer: Kingdom Bacteria (or Eubacteria) — often classified under Domain Bacteria
#### 24. Cell walls of bacteria lack
- Answer: Peptidoglycan – wait, no! Actually, bacterial cell walls DO contain peptidoglycan.
- But archaea lack peptidoglycan.
- So the correct answer is: Bacteria have peptidoglycan in their cell walls.
- If the question says "lack", it may be referring to something else.
Wait — let's rephrase:
"Cell walls of bacteria lack" — this might be a trick. Actually, bacterial cell walls have peptidoglycan. So perhaps the intended answer is:
> They lack cellulose or chitin — unlike plant or fungal cells.
But more accurately: Bacterial cell walls lack membrane-bound organelles — but that’s not about the wall.
Best answer: Bacterial cell walls lack chitin (found in fungi) and cellulose (in plants).
But if the question is asking what they don’t have, the most common answer is:
> ✔ They lack a nucleus and membrane-bound organelles — but that's not the cell wall.
So likely: Bacterial cell walls contain peptidoglycan, which is not found in eukaryotes.
Perhaps the question is:
"Cell walls of bacteria lack..." → "they do not have a nucleus" — but again, that’s not the wall.
Better interpretation: "What do bacterial cell walls lack?" → They lack chitin and cellulose.
But standard answer: Bacterial cell walls are made of peptidoglycan, which is unique to bacteria.
So if the question is:
"Cell walls of bacteria lack..." → possibly "membrane-bound organelles" — no, that’s not in the wall.
✔ Final answer: They lack cellulose and chitin — so they don't have those materials in their cell walls.
---
#### 25. Two ways bacteria cause disease:
1. Toxins – produce harmful substances (e.g., *Clostridium botulinum* produces botulinum toxin).
2. Invasion – invade and destroy host tissues (e.g., *Streptococcus pyogenes* causing strep throat).
---
#### 26. What is the structural level of bacteria?
- Answer: Prokaryotic cells — they are unicellular, lack a nucleus, and have no membrane-bound organelles.
---
#### 27. A symbiotic relationship exists between ___ and ___ in the human gut.
- Answer: Humans and beneficial bacteria (e.g., *Lactobacillus*, *Bifidobacterium*)
- Example: Escherichia coli in the large intestine helps digest food and produce vitamins (like vitamin K).
- This is a mutualistic relationship: both benefit.
---
| Question | Answer |
|--------|--------|
| 1 | Made of nucleic acid + protein coat; lacks cellular structure |
| 2 | No, viruses are not in a kingdom |
| 3 | Need a host cell to replicate |
| 4 | RNA viruses (or retroviruses) |
| 5 | Bacteriophage; Prion (not a virus) — but Mad Cow is caused by prion |
| 6 | Diagram matching: D→attach, A→inject, B→copy, E→assemble, C→release |
| 23 | Kingdom Bacteria |
| 24 | Lack chitin and cellulose (or lack nucleus/organelles — but context matters) |
| 25 | Toxins and invasion |
| 26 | Prokaryotic cells |
| 27 | Humans and beneficial bacteria (e.g., *E. coli*) |
---
If you can provide a clearer version of the worksheet or specify which questions you're stuck on, I can give even more precise help!
Let’s go through what we can see and provide accurate answers with explanations:
---
1. What is the structural level of a virus? What does it NOT have?
- Answer: A virus is made of nucleic acid (DNA or RNA) surrounded by a protein coat (capsid). Some viruses also have an outer envelope.
- What it does NOT have: Viruses do not have cellular structures like ribosomes, cytoplasm, or organelles. They also lack metabolic machinery and cannot reproduce on their own.
> 🔍 *Explanation*: Viruses are acellular—meaning they are not cells. They rely entirely on host cells to replicate.
---
2. Do viruses belong to a kingdom?
- Answer: No, viruses do not belong to any kingdom.
- Reason: Viruses are not considered living organisms because they lack key characteristics of life such as metabolism, growth, and independent reproduction.
---
3. What do viruses have to support?
- Answer: Viruses need a host cell to replicate and carry out their life cycle.
- Explanation: They are obligate intracellular parasites—they must infect a living cell to reproduce.
---
4. Viruses that contain RNA are called...
- Answer: Retroviruses (if they reverse transcribe RNA into DNA) or more generally, RNA viruses.
- Note: Not all RNA viruses are retroviruses. For example, influenza is an RNA virus but not a retrovirus.
---
5. Give an example:
- Name of virus that attacks bacteria: Bacteriophage (e.g., T4 phage)
- Virus that causes "Mad Cow Disease": Prion (but note: prions are not viruses; they are misfolded proteins). The actual cause of Mad Cow disease is a prion, not a virus.
- However, if the question expects a virus, it might be a trick—no virus causes Mad Cow disease. It's caused by prions.
- But if it's asking for a viral disease in cows, then Bovine Viral Diarrhea Virus (BVDV) could be an example.
> 🚨 Clarification: "Mad Cow Disease" = Bovine Spongiform Encephalopathy (BSE) → caused by prions, not viruses.
---
6. Match the letter in the diagram (right) with the step:
Assuming the diagram shows the viral replication cycle (e.g., lytic cycle):
| Step | Description | Letter |
|------|-------------|--------|
| 8. | Host nuclear acid is injected into host cell | A |
| 9. | The virus’ nucleic acid is copied | B |
| 10. | The host cell explodes, releasing C | C |
| 11. | The virus attaches itself to the host cell | D |
| 12. | Cell reproduces more viruses | E |
> 🔎 *Explanation*:
> - D: Attachment
> - A: Penetration (injection of genetic material)
> - B: Replication of viral genome
> - E: Assembly of new viruses
> - C: Release (lysis)
This follows the lytic cycle of a bacteriophage.
---
7. BACTERIA:
#### 23. Kingdoms of true bacteria
- Answer: Kingdom Bacteria (or Eubacteria) — often classified under Domain Bacteria
#### 24. Cell walls of bacteria lack
- Answer: Peptidoglycan – wait, no! Actually, bacterial cell walls DO contain peptidoglycan.
- But archaea lack peptidoglycan.
- So the correct answer is: Bacteria have peptidoglycan in their cell walls.
- If the question says "lack", it may be referring to something else.
Wait — let's rephrase:
"Cell walls of bacteria lack" — this might be a trick. Actually, bacterial cell walls have peptidoglycan. So perhaps the intended answer is:
> They lack cellulose or chitin — unlike plant or fungal cells.
But more accurately: Bacterial cell walls lack membrane-bound organelles — but that’s not about the wall.
Best answer: Bacterial cell walls lack chitin (found in fungi) and cellulose (in plants).
But if the question is asking what they don’t have, the most common answer is:
> ✔ They lack a nucleus and membrane-bound organelles — but that's not the cell wall.
So likely: Bacterial cell walls contain peptidoglycan, which is not found in eukaryotes.
Perhaps the question is:
"Cell walls of bacteria lack..." → "they do not have a nucleus" — but again, that’s not the wall.
Better interpretation: "What do bacterial cell walls lack?" → They lack chitin and cellulose.
But standard answer: Bacterial cell walls are made of peptidoglycan, which is unique to bacteria.
So if the question is:
"Cell walls of bacteria lack..." → possibly "membrane-bound organelles" — no, that’s not in the wall.
✔ Final answer: They lack cellulose and chitin — so they don't have those materials in their cell walls.
---
#### 25. Two ways bacteria cause disease:
1. Toxins – produce harmful substances (e.g., *Clostridium botulinum* produces botulinum toxin).
2. Invasion – invade and destroy host tissues (e.g., *Streptococcus pyogenes* causing strep throat).
---
#### 26. What is the structural level of bacteria?
- Answer: Prokaryotic cells — they are unicellular, lack a nucleus, and have no membrane-bound organelles.
---
#### 27. A symbiotic relationship exists between ___ and ___ in the human gut.
- Answer: Humans and beneficial bacteria (e.g., *Lactobacillus*, *Bifidobacterium*)
- Example: Escherichia coli in the large intestine helps digest food and produce vitamins (like vitamin K).
- This is a mutualistic relationship: both benefit.
---
✔ Summary of Key Answers:
| Question | Answer |
|--------|--------|
| 1 | Made of nucleic acid + protein coat; lacks cellular structure |
| 2 | No, viruses are not in a kingdom |
| 3 | Need a host cell to replicate |
| 4 | RNA viruses (or retroviruses) |
| 5 | Bacteriophage; Prion (not a virus) — but Mad Cow is caused by prion |
| 6 | Diagram matching: D→attach, A→inject, B→copy, E→assemble, C→release |
| 23 | Kingdom Bacteria |
| 24 | Lack chitin and cellulose (or lack nucleus/organelles — but context matters) |
| 25 | Toxins and invasion |
| 26 | Prokaryotic cells |
| 27 | Humans and beneficial bacteria (e.g., *E. coli*) |
---
If you can provide a clearer version of the worksheet or specify which questions you're stuck on, I can give even more precise help!
Parent Tip: Review the logic above to help your child master the concept of virus and bacteria worksheet answer key.
