Plant Cell and Animal Cell Worksheet showing structural differences between plant and animal cells with labeled components.

Let's solve each question based on the Plant Cell and Animal Cell Worksheet diagram. We'll identify the labeled parts and answer each question with explanations.

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Diagram Overview:

- Diagram 1: Plant Cell
- Diagram 2: Animal Cell

Labeled structures:
- A → Cell membrane (common to both)
- B → Cell wall (plant cell only)
- C → Cytoplasm
- D → Vacuole (large in plant cells)
- E → Nucleus
- F → Centrioles (only in animal cells)
- G → Centrosome (includes centrioles)
- H → Mitochondrion
- I → Nucleus (with nucleolus)
- J → Endoplasmic Reticulum (ER) — rough ER (with ribosomes)

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Answers & Explanations

#### 1. Identify the structure labelled B, which is a justification for considering diagram 1 as a plant cell?
✔ Answer: Cell wall

🔹 Explanation:
The cell wall (labeled B) is a rigid structure outside the cell membrane found only in plant cells, fungi, and some bacteria. It provides structural support and protection. Its presence is a key feature distinguishing plant cells from animal cells.

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#### 2. The structure labeled A is present in all prokaryotic and eukaryotic cells. The structure is .....
✔ Answer: Cell membrane

🔹 Explanation:
The cell membrane (A) regulates the movement of substances in and out of the cell. It is present in all living cells, whether prokaryotic (like bacteria) or eukaryotic (plants, animals, fungi). It is a universal feature of life.

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#### 3. The organelle labeled H is responsible for life in this planet and animal cells lack this organelle. The organelle is.....
✔ Answer: Chloroplast

🔹 Explanation:
Wait! There’s a mistake in the labeling here.
In the diagram, H is pointing to mitochondria, not chloroplasts. But the clue says "animal cells lack this organelle" and "responsible for life on Earth" — that points to chloroplasts, which perform photosynthesis.

But looking closely:
- In plant cell, H is pointing to mitochondria (not chloroplasts).
- However, chloroplasts are missing from the labels.

This seems like a labeling error. Let's check again:

Actually, in the diagram:
- H is labeled near mitochondria in the plant cell.
- But chloroplasts are present in the plant cell but not labeled.

So likely, the question has a typo — it should say "structure labeled ???" instead of H.

But assuming H is mitochondria, then this question doesn’t make sense because:
- Mitochondria are in both plant and animal cells.
- Chloroplasts are only in plants and do photosynthesis.

Therefore, the correct organelle described ("responsible for life on Earth", absent in animal cells) is chloroplast.

But since H is not chloroplast, there might be an error in the diagram or label.

Wait — let's double-check the diagram:

Looking at the plant cell:
- The large oval structure with internal stacks is chloroplast — but it's not labeled.
- H points to mitochondria.

So unless H was meant to point to chloroplast, this is incorrect.

But given the context, likely the intended answer is chloroplast, even if mislabeled.

✔ Correct Answer: Chloroplast

🔹 Explanation:
Chloroplasts are the site of photosynthesis, converting sunlight into energy (glucose), which supports most life on Earth. They are unique to plant cells and some protists. Animal cells do not have chloroplasts.

> ⚠️ Note: If H is truly mitochondria, then this question is flawed. But based on content, the intended answer is chloroplast.

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#### 4. This is the physical basis of life where all organelles are present. The site labeled C is ...
✔ Answer: Cytoplasm

🔹 Explanation:
The cytoplasm (C) is the gel-like substance inside the cell membrane where all organelles are suspended. It's the medium in which cellular processes occur and is essential for maintaining cell structure and function.

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#### 5. The structure labeled E is called “CPU of the cell” where the genetic material resides. It is the ....
✔ Answer: Nucleus

🔹 Explanation:
The nucleus (E) contains DNA, the genetic material, and controls cell activities such as growth, metabolism, and reproduction. It's often called the "control center" or "CPU" of the cell.

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#### 6. The structure labeled G give rise to spindle fibers and exclusively seen in animal cell. The structure is called .....
✔ Answer: Centrosome

🔹 Explanation:
The centrosome (G) includes two centrioles and organizes microtubules during cell division. It forms the spindle fibers that separate chromosomes. It is found only in animal cells, not in plant cells.

> ✔ Note: Centrioles are part of the centrosome. So G = centrosome.

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#### 7. The organelle H is the “power house of the cell” in all eukaryotes where ATP is synthesized. The organelle .....
✔ Answer: Mitochondrion

🔹 Explanation:
The mitochondrion (H) is known as the "powerhouse" because it produces ATP through cellular respiration. It is present in all eukaryotic cells, including both plant and animal cells.

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#### 8. It is the site of synthesis of secretory proteins. The organelle labeled J is ...
✔ Answer: Rough Endoplasmic Reticulum (Rough ER)

🔹 Explanation:
The rough ER (J) has ribosomes attached to its surface. These ribosomes synthesize proteins that are either secreted from the cell or inserted into membranes. So, it's the site of secretory protein synthesis.

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#### 9. It is the site of lipid biosynthesis and drug detoxification. The organelle labeled J is ...
✘ Wait — this contradicts #8.

But J is one structure, so can't be both.

Let’s clarify:

- Rough ER (J) → protein synthesis
- Smooth ER → lipid synthesis, detoxification

But in the diagram, J is labeled on the rough ER (has ribosomes).

So this question is incorrect — smooth ER does lipid synthesis and detox.

But if J is rough ER, then this question is wrong.

Wait — maybe J is smooth ER?

Look at the diagram:
- J is labeled on a network of membranes without ribosomes? Or with?
- In the animal cell, J appears to be smooth ER (no ribosomes shown), while F is near the nucleus and may be rough ER.

Wait — actually, J is labeled on a structure without ribosomes — so it's smooth ER.

But in many diagrams, rough ER is shown with ribosomes.

Re-examining:
- J is labeled on a structure without ribosomes — so it's smooth ER.
- F is near the nucleus and has ribosomes — that’s rough ER.

But the label J is pointing to smooth ER.

So:
- J = Smooth ER

✔ Answer: Smooth Endoplasmic Reticulum (Smooth ER)

🔹 Explanation:
Smooth ER lacks ribosomes and is involved in:
- Lipid synthesis (e.g., phospholipids, steroids)
- Detoxification of drugs and poisons (especially in liver cells)

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#### 10. Unlike animal cells, plant cells possess cell wall and large vacuole. In the diagram, it is labeled as .....
✔ Answer: D

🔹 Explanation:
The large central vacuole (D) is a defining feature of mature plant cells. It stores water, maintains turgor pressure, and helps in waste storage. Animal cells have small vesicles, but not large central vacuoles.

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✔ Final Answers Summary:

| Question | Answer |
|--------|--------|
| 1 | Cell wall |
| 2 | Cell membrane |
| 3 | Chloroplast *(note: possibly mislabeled in diagram)* |
| 4 | Cytoplasm |
| 5 | Nucleus |
| 6 | Centrosome |
| 7 | Mitochondrion |
| 8 | Rough Endoplasmic Reticulum *(but J is smooth ER — contradiction)* |
| 9 | Smooth Endoplasmic Reticulum *(correct if J is smooth ER)* |
| 10 | D (Vacuole) |

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🔍 Clarification on Conflicts:

- Question 8 vs 9: Both refer to J, but describe different functions.
- Rough ER → protein synthesis
- Smooth ER → lipid synthesis and detox
- So J must be smooth ER for Q9 to be correct.
- But Q8 says J is for protein synthesis → implies rough ER.

➡️ Conclusion: Likely, J is labeled incorrectly in the diagram or questions.

But based on standard labeling:
- If J has no ribosomes → smooth ER → Q9 is correct.
- Then Q8 should refer to rough ER, which is not labeled.

Possibly, F is rough ER, and J is smooth ER.

So:
- Q8: "Site of secretory protein synthesis" → Rough ER → but not labeled as J → error
- Q9: "Lipid synthesis and detox" → Smooth ER → J → ✔

So perhaps Q8 has a typo — it should refer to rough ER, not J.

Alternatively, J is meant to be rough ER.

But visually, J appears to be smooth ER.

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🟩 Final Corrected Answers:

1. Cell wall
2. Cell membrane
3. Chloroplast
4. Cytoplasm
5. Nucleus
6. Centrosome
7. Mitochondrion
8. Rough Endoplasmic Reticulum (but likely not J — probably F or another unlabeled part)
9. Smooth Endoplasmic Reticulum (if J is smooth ER)
10. D (Vacuole)

> 💡 Recommendation: Check if the diagram labels are accurate. If J is smooth ER, then Q8 is incorrect. If J is rough ER, then Q9 is incorrect.

But based on typical diagrams and logic:
- J = Smooth ER → Q9 is correct
- Rough ER is unlabeled or labeled elsewhere

So Q8 likely refers to rough ER, but it's not labeled as J.

Thus, Q8 may have a mistake.

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✔ Final Answer Key (Assuming Diagram Labels Are Correct):

| Q | Answer |
|---|--------|
| 1 | Cell wall |
| 2 | Cell membrane |
| 3 | Chloroplast |
| 4 | Cytoplasm |
| 5 | Nucleus |
| 6 | Centrosome |
| 7 | Mitochondrion |
| 8 | Rough Endoplasmic Reticulum |
| 9 | Smooth Endoplasmic Reticulum |
| 10 | D |

> ⚠️ Note: Questions 8 and 9 may conflict if J is only one structure. Likely, J is smooth ER, so Q8 should refer to another structure (perhaps F or I). But without clearer labeling, we go by standard knowledge.

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Let me know if you'd like a corrected version of the worksheet!