Homologous
The fins of fishes and flipper of a whale are homologous structures since they have different structure but similar structure
Answer:
In the mentioned scenario, norepinephrine and acetylcholine are the neurotransmitters, which would have been present at the higher concentrations in Sean's brain. Norepinephrine signifies to a neurotransmitter that plays an important part in dreaming, emotions, sleeping, attentiveness, and learning.
It also gets released in the bloodstream as a hormone, where it augments the rate of heart and causes the blood vessels to contract. Another neurotransmitter called acetylcholine signifies the chemical that is released by the motor neurons to instigate the muscles.
Answer: lithosphere (land), hydrosphere (water), biosphere (living things), and atmosphere (air).
Explanation: Hope this helps!!!
