Describe what convection currents are in detail.

Convection is a form of heat transfer.Convection currents uses mass motion to transfer heat. It moves free-moving particles of fluid (or gas)from one place to another. The process happens because of difference occurring in temperature between the two parts of fluid. The temperature difference causes the hot fluids to rise and the cold fluids to sink, creating a current.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u