Nerve cells communicate by sending an electrical signal through an axon, from this molecules get released into the synapse this then binds itself onto receptor sites. With ion-linked channel receptors, the ligands get binded to a protein. The ion channels are then opened and the proccess gets repeated. Does that help?
2. A
3. D (got cut off but the others don’t seem right)
4. D
Hopefully these are correct
The polymerase chain reaction makes DNA fingerprinting more reliable because it allows scientists to quickly make many copies of DNA the answer is C
Answer:
Gas exchange between tissues and the blood is an essential function of the circulatory. The air contains oxygen that crosses the lung tissue, enters the bloodstream, and the alveoli are in direct contact with capillaries of the circulatory system. As water flows over the gills, oxygen is transferred to blood via the veins.
Explanation: