Answer:
constant = changes and control is used as the basis of comparison
Explanation:
Constant variables are variables that do not change
e.g such as the temperature ( if it's meant to be kept at a constant temp).
Control variables are meant to be kept constant to allow for a comparison and thus determine the effect of IV (independant variable) and DV ( dependant variable)
Cells lining the small intestine are specialized for absorption of nutrients. their plasma membrane <span>has </span><span>microvillus </span>(plural:<span> m</span>icrovilli)<span> which</span><span> increase cell surface area. These are cellular membranes that are microscopic in nature that increases the surface area of the cell for diffusion and minimize increase in volume.</span><span> </span>
Answer: Like fats, they are typically composed of fatty acid chains attached to a backbone of glycerol. Instead having three fatty acid tails, however, phospholipids generally have just two, and the third carbon of the glycerol backbone is occupied by a modified phosphate group.