When you smoke a cigarette, the components; e.g. nicotine and carbon monoxide enter the lungs and are absorbed into the bloodstream. They are carried by the Red Blood Cells to the blood-brain barrier, here, nicotine binds to nicotinic acetylcholine receptors (nAChRs), resulting to a cascade that results to release of dopamine (good-feeling neurotransmitter).
B. They decrease. As more we use the sources of nature, the less is left.
B. sexual selection, which alters allele frequencies in the gene pool.
Answer:sea levels dropped 300 ft
Explanation:gang
