Grade 7 - Worksheets - Integrated Science - Free Printable

Let's solve the worksheet step by step.

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A. Define the term "cell".

Answer:
A cell is the smallest unit of structure and function in living organisms. It is the basic building block of all living things. Cells carry out essential life processes such as growth, reproduction, response to stimuli, and metabolism.

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B. Name the parts of the plant cell below:

We are given a labeled diagram of a plant cell with numbers 1 to 15. Let's identify each part based on standard plant cell anatomy.

Here’s the identification:

1. Chloroplast – Green organelles that carry out photosynthesis.
2. Nuclear envelope (or nuclear membrane) – The double membrane surrounding the nucleus.
3. Nucleus – Contains genetic material (DNA) and controls cell activities.
4. Cell wall – Rigid outer layer that provides support and protection.
5. Vacuole – Large central sac that stores water, ions, and waste; helps maintain turgor pressure.
6. Cytoplasm – Gel-like substance where organelles are suspended.
7. Mitochondrion – Organelle responsible for cellular respiration (produces energy).
8. Golgi apparatus – Modifies, sorts, and packages proteins and lipids.
9. Ribosome – Site of protein synthesis (often seen attached to the rough ER).
10. Endoplasmic reticulum (Rough ER) – Network of membranes studded with ribosomes.
11. Smooth endoplasmic reticulum – Lacks ribosomes; involved in lipid synthesis and detoxification.
12. Plasma membrane (cell membrane) – Controls movement of substances in and out of the cell.
13. Lysosome – Contains digestive enzymes to break down waste materials.
14. Centriole – Involved in cell division (note: centrioles are typically absent in most plant cells, but may be shown here for comparison or error).
15. Microtubule – Part of the cytoskeleton that helps maintain cell shape and aids in transport.

> Note: In actual plant cells, centrioles (14) are generally not present. They are found in animal cells. However, since it's labeled in the diagram, we include it as per the image. This might be an error or included for comparative purposes.

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✔ Final Answers:

#### A. Define the term "cell":
A cell is the smallest structural and functional unit of life. It is the basic building block of all living organisms and carries out essential life processes like metabolism, growth, and reproduction.

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#### B. Labeling the Plant Cell:

| Number | Part |
|--------|------|
| 1 | Chloroplast |
| 2 | Nuclear envelope |
| 3 | Nucleus |
| 4 | Cell wall |
| 5 | Vacuole |
| 6 | Cytoplasm |
| 7 | Mitochondrion |
| 8 | Golgi apparatus |
| 9 | Ribosome |
| 10 | Rough Endoplasmic Reticulum (RER) |
| 11 | Smooth Endoplasmic Reticulum (SER) |
| 12 | Plasma membrane |
| 13 | Lysosome |
| 14 | Centriole *(Note: Not typically in plant cells)* |
| 15 | Microtubule |

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✔ Summary:
This worksheet tests foundational knowledge of plant cell structure and definitions. The key is recognizing each organelle and understanding its role. While some structures like centrioles are more common in animal cells, they may appear in diagrams for educational comparison.

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