Q: What is the outer layer of an axon that acts like a layer of insulation, similar to the plastic that encases an electrical cord? Read this paragraph and choose the correct option from the provided answers: The axon of many neurons has an outer layer called a myelin sheath (see Figure above ). Myelin is a lipid produced by a type of a glial cell known as a Schwann cell. The myelin sheath acts like a layer of insulation, similar to the plastic that encases an electrical cord. Regularly spaced nodes, or gaps, in the myelin sheath allow nerve impulses to skip along the axon very rapidly. Choices: - lipids sheath - nerve sheath - layer sheath - myelin sheath A:
myelin sheath

Q: Where do most of the steps of cellular respiration take place? Read this paragraph and choose the correct option from the provided answers: Most of the steps of cellular respiration take place in the mitochondria. Choices: - ribosomes - nucleus - cytoplasm - mitochondria A:
mitochondria

Q: In single-celled organisms, what does the plasma membrane extensions help the organisms to do? Read this paragraph and choose the correct option from the provided answers: The plasma membrane may have extensions, such as whip-like flagella or brush-like cilia . In single-celled organisms, like those shown in Figure below , the membrane extensions may help the organisms move. In multicellular organisms, the extensions have other functions. For example, the cilia on human lung cells sweep foreign particles and mucus toward the mouth and nose. Choices: - increase - inspect - prevent - move A:
move

Q: What is the process when animals maintain an internal temperature? Read this paragraph and choose the correct option from the provided answers: Choices: - osmoregulation - bioaccumulation - homeostasis - thermoregulation A:
thermoregulation