Answer:
A. Move substances down a concentration gradient
Explanation:
Active transport is the process of transport of substances in an energy dependent manner. The process of active transport requires energy to transport the substances against their concentration gradient. This means that active transport moves the substances from the region of their lower concentration to that of higher concentration.
Answer: The three different types of protists are protozoa, algae and fungus-like protists. These types are categorized by how they obtain nutrition. Protists can be unicellular, colonial or multicellular. Each type of protist has its own phylums or divisions.
Answer:Myelin is a lipid-rich (fatty) substance that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon.
Explanation:
Water has those melting and boiling points.
