Increase with a stimulant and decrease with a depressant
Explanation:
Stimulants and depressants are observed using various organisms. The way a stimulant works is by increasing the dopamine levels in the body. This in turn causes increased heart rate as would be seen in the chick embryo heart. On the other hand a depressant would lower dopamine levels. This would reduce the neurotransmitter and cause the heart rate to slow down.
<em>The most common chemical sedimentary rock, by far, is limestone . Others include chert , banded iron formation , and evaporite</em><em>s</em><em>.</em>
