Answer:
An asteroid impact.
Explanation:
An asteroid impact is considered to have tossed rubble across the earth, killing off many species of plants and animals, 65 million years ago. Volcanic activity is involved in at least four mass extinctions, whereas an asteroid in just one.
Answer:
Animals get rid of nitrogen by converting it int urea uric, acid and ammonia.
Explanation:
Only known planet to have oceans of liquid water is Earth.
Answer:
DNA is being transcribed into mRNA
Explanation:
Methamphetamine is neurotoxic to dopaminergic neurons in the human’s midbrain. It increases the amount of the dopamine in the brain and as a result, produces the euphoria feeling that many people experience. It is also indicated that high-dose methamphetamine use can be neurotoxic to serotonin neurons (with the potential of damaging neurons)<span>.</span>