Where in the cell do the reactions of glycolysis take place?

What are the four basic classes of organic molecules how do they differ structurally and functionally

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Chloroplasts and bacteria are in size. a. similar b. at different ends of the size range c. exactly the same d. none of these