Science - Grade 8 - QED - Free Printable

Let's solve the Plant Cell and Animal Cell Worksheet step by step, based on the diagram and questions provided.

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Diagram Overview:

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

We are given labeled parts (A–J) in both cells. Let’s identify each structure first:

#### Labeled Structures:

| Label | Structure Name |
|-------|----------------|
| A | Cell membrane |
| B | Cell wall |
| C | Cytoplasm |
| D | Vacuole |
| E | Nucleus |
| F | Ribosomes |
| G | Centrioles |
| H | Mitochondria |
| I | Chloroplasts |
| J | Endoplasmic Reticulum (ER) |

> Note: In plant cells, I is chloroplast, which is absent in animal cells.
> In animal cells, G is centrioles, which are not found in most plant cells.

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Now let's answer each question one by one:

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1. Identify the structure labelled B, which is a justification for considering diagram 1 as a plant cell?

✔ Answer: Cell wall

- The cell wall (labeled B) is present in plant cells but not in animal cells.
- It provides structural support and protection to plant cells.
- This 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

- The cell membrane (A) regulates what enters and exits the cell.
- It is present in all living cells, including prokaryotes (like bacteria) and eukaryotes (plants, animals, fungi, protists).

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3. The organelle labeled I is responsible for life in this planet and animal cells lack this organelle. The organelle is...

✔ Answer: Chloroplast

- Chloroplasts (I) are the site of photosynthesis in plant cells.
- They convert light energy into chemical energy (glucose), which supports most life on Earth.
- Animal cells do not have chloroplasts.

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4. This is the physical basis of life where all organelles are present. The site labeled C is...

✔ Answer: Cytoplasm

- The cytoplasm (C) is the gel-like substance inside the cell where organelles are suspended.
- It's the medium for biochemical reactions and supports cellular processes.

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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

- The nucleus (E) contains DNA (genetic material).
- It controls cell activities such as growth, reproduction, and protein synthesis — hence called the "brain" 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: Centrioles

- Centrioles (G) are involved in organizing the spindle fibers during cell division (mitosis).
- Found only in animal cells (not in most plant cells).
- They help in chromosome separation.

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7. The organelle H is the "power house of the cell" in all eukaryotes where ATP is synthesized. The organelle is...

✔ Answer: Mitochondria

- Mitochondria (H) produce ATP via cellular respiration.
- Known as the "powerhouse" because they generate energy for the cell.
- Present in 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: Endoplasmic Reticulum (ER)

- More specifically, the rough endoplasmic reticulum (RER) has ribosomes on its surface and is involved in protein synthesis.
- Secretory proteins are made here and then sent to the Golgi apparatus for packaging.
- J likely refers to the Rough ER.

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9. It is the site of lipid biosynthesis and drug detoxification. The organelle labeled J is...

⚠️ Wait! This is tricky — same label J, but different function?

Let’s clarify:

- Smooth ER (SER) is responsible for:
- Lipid synthesis
- Detoxification of drugs and poisons
- Calcium storage

So if J is labeled as endoplasmic reticulum, it can be either rough or smooth depending on context.

But since Question 8 refers to secretory proteins → Rough ER,
and Question 9 refers to lipid biosynthesis & detoxification → Smooth ER,

This suggests that J may represent the entire ER system, or possibly the diagram shows both types.

However, in many diagrams, J points to the endoplasmic reticulum generally.

But to answer correctly:

✔ Answer: Smooth Endoplasmic Reticulum (SER)

> But note: Since the label J is used for both functions, and typically one label can't refer to two different parts, we assume J = Endoplasmic Reticulum, and depending on the region, it can be rough or smooth.

So best answer:
✔ Endoplasmic Reticulum (specifically Smooth ER for this function)

But since the question says “The organelle labeled J is…”, and J is likely the entire ER network:

👉 Answer: Endoplasmic Reticulum (Smooth ER)

(Or more precisely: Smooth Endoplasmic Reticulum)

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

✔ Answer: B and D

- B = Cell wall
- D = Large central vacuole

Both are features unique to plant cells (in mature cells).

So the correct answer should include both:

👉 B and D

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✔ Final Answers Summary:

| Question | Answer |
|--------|--------|
| 1 | Cell wall |
| 2 | Cell membrane |
| 3 | Chloroplast |
| 4 | Cytoplasm |
| 5 | Nucleus |
| 6 | Centrioles |
| 7 | Mitochondria |
| 8 | Rough Endoplasmic Reticulum (or simply Endoplasmic Reticulum) |
| 9 | Smooth Endoplasmic Reticulum |
| 10 | B and D |

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🔍 Notes:

- Label J appears to point to the endoplasmic reticulum, which includes both rough and smooth regions.
- In some diagrams, J might be pointing to the Golgi apparatus, but here it's clearly connected to the ER network.
- Vacuole (D) is much larger in plant cells than in animal cells.

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✔ You can now check your answers at the provided link: [http://bit.ly/2hjBJmo](http://bit.ly/2hjBJmo)

Let me know if you'd like a labeled version of the diagram or further explanation!