What do you think the dark spot is in the middle of cheek ce

What do you think the dark spot is in the middle of cheek cells? Did onion cells have a similar feature? Bacterial cells? Why or why not?

Solution

dark spot is in the middle of cheek cells is the nucleus.

Onion cells also have the nucleus which is located peripherally owing to the presence of large vacuole.

Bacterial cells lack membrane bound nucleus, they carry a circular DNA instead in the cytosol. Since it is spread out naked in the cytoplasm it is not dense hence doesnot look like a dark spot.