When the race is almost to begin, nervous system sends signals to the heart causing the respiratory rate to increase. since there is an increase in heart rate, breathing and sweating becomes increases in order to maintain a normal body temperature.
By tar, I think you mean nicotine. (I Hope). It affects the nerve signals that regulate breathing.
Answer: There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.
Explanation: It seems like that´s right
