An organism that lives in environmental conditions so extreme that few other species can survive there are .
1. extremophiles
2. extreme halophiles ("salt lovers")
2. extreme thermophiles ("heat lovers")

extremophiles

Explanation:

Extremophiles are living organisms that are adapted to survive extreme environmental conditions such as high pH, high temperatures or high pressure.

Examples of extremophiles include many Prokaryotes like bacteria and cyanobacteria, as they can be found in volcanic areas.

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:

answer: c.

explanation: