Which letter correctly identifies the 5 levels of organization from simplest to the most complex? A) person, muscle cell, heart, circulatory system, cardiac muscle tissue
B) muscle cell, heart, cardiac muscle tissue, circulatory system, person
C) muscle cell, cardiac muscle tissue, heart, circulatory system, person
D) person, circulatory system, heart, cardiac muscle tissue, muscle cell

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:

the answer to you question is   jet streams

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.