Which structure in the cell shown in figure 7–2 above stores materials, such as water, salts, proteins, and carbohydrates?
a. structure a
b. structure b
c. structure c
d. structure d

The answer is C. These structures are vacuoles and are found in plants cell (you can tell it’s a plant cell because of the outer cell wall in the picture). Vacuoles have a variety of other functions storage of waste products, maintain turgor pressure  for plants support.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?