A) Active transport
Osmosis - active transport - substances move from low to high concentration
Cocaine appears to produce its effects largely by increasing the supply of the neurotransmitter dopamine at key neurons throughout the brain. The missing word is dopamine. I hope this is the answer that you were looking for.
The correct answer would be C.seasonal changes in the amount of daylight. Since leaves require sunlight in order to perform photosynthesis to keep the tree alive, when seasonal changes occur where there is not enough sunlight throughout the day, trees go dormant for the season until conditions are right.
What statement do you mean?
