Astudent is observing a cell on a microscope slide and notices cell walls and membrane-bound organelles the student concludes that the cells a. must be animal cells b. must be bacteria cells c. must be plant cells d. could be all of the above

The right answer is C. must be plant cells.

The bacteria certainly have a wall but do not have organelles.

Animal cells have no wall.

The plant cells are the very numerous elementary units constituting the vegetable organisms.

They generally comprise a cell nucleus surrounded by a cytoplasm, various organelles or plastids, all protected by a cell membrane. They can measure between 10 and 200 μm.

Plant cells are living systems. They are very different from the cells of organisms belonging to other eukaryotes. The main distinguishing features are:

*Large central vacuole (surrounded by a membrane, the tonoplast), which maintains the turgor of the cell and controls the exchange of molecules between the cytosol and the sap. These vacuoles serve as bins for plant cells, at the end of cell life, these vacuoles take up 90% of the cell space.

*A pectocellulosic wall made of cellulose and proteins, as well as lignin in many cases, and deposited by the protoplast outside the cell membrane. It is opposed to the cell wall of fungi, made of chitin, and prokaryotes, made of peptidoglycans.

*Plasmodesms, connecting the pores of the cell wall, which allows each plant cell to communicate with adjacent cells. This system is different from the network of hyphae present in fungi.

*Plastids, especially chloroplasts, which contain chlorophyll, the pigment that gives plants their green color and is involved in the process of photosynthesis.

*The absence of centrosomes that are present in animal cells.

it cools slower in the earth meaning the crystals have more time to form than lava on the surface