A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular. Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall.

Introduction:
Plant and animal cells are the two basic types of eukaryotic cells, but they have several differences in terms of structure and function. Understanding these differences is essential to comprehend the diverse characteristics and roles of plant and animal cells.

1. Cell Wall and Cell Membrane:
- Plant cells have a rigid cell wall composed of cellulose that provides structural support and protection.
- Animal cells lack a cell wall but have a flexible cell membrane that regulates the movement of substances in and out of the cell.

2. Chloroplasts:
- Plant cells contain chloroplasts, which are responsible for photosynthesis, the process of converting sunlight into energy. Chloroplasts contain chlorophyll, giving plants their green color.
- Animal cells do not have chloroplasts as they obtain energy through the consumption of organic matter.

3. Vacuoles:
- Plant cells possess a large central vacuole that stores water, ions, and nutrients. It helps maintain the shape and turgidity of the cell.
- Animal cells have smaller and multiple vacuoles that are involved in the storage of waste materials and water regulation.

4. Shape and Size:
- Plant cells are generally rectangular in shape and have fixed sizes.
- Animal cells have more varied shapes and sizes, depending on the tissue type and function.

5. Lysosomes:
- Plant cells have fewer lysosomes, which are responsible for the breakdown of waste materials and cellular components.
- Animal cells contain numerous lysosomes that aid in digestion and recycling within the cell.

6. Centrioles:
- Plant cells lack centrioles, which are involved in cell division.
- Animal cells have centrioles, which aid in the formation of spindle fibers during cell division.

7. Plastids:
- Plant cells may contain other specialized organelles called plastids, such as leucoplasts (involved in the synthesis and storage of starch) and chromoplasts (responsible for pigment synthesis).
- Animal cells do not possess plastids.

Conclusion:
In summary, plant and animal cells differ in terms of cell wall, chloroplasts, vacuoles, shape, lysosomes, centrioles, and the presence of plastids. These variations enable plant and animal cells to perform their respective functions and contribute to the overall complexity and diversity of living organisms.