C. 5 1/2 because <span>A sleep cycle lasts about 90 minutes and during that time we move through five stages of sleep </span>
Respiratory rate: A person's respiratory rate is the number of breaths you take per minute. The normal respiration rate for an adult at rest is 12 to 20 breaths per minute. A respiration rate under 12 or over 25 breaths per minute while resting is considered abnormal.
Cerebrum controls the higher brain function such as speech, writing, etc. The cerebellum controls the involuntary stuff such as your digestive track, breathing, etc. The other 2 control a branch of other stuff. C is your answer.
Answer:
The correct answer is- Immune system
Explanation:
There are physical, chemical and immunological barriers present in our body which helps us to protect from the foreign antigen. They all assist each other and helps in pathogen removal from our body.
The physical barrier includes skin, gastrointestinal tract, respiratory tract, etc which do not allow the microbe to enter the body. Chemical barriers include tear, saliva, acid in the stomach which kills microbes on the body surface.
Immune cells like macrophages, B cells kills microbes when it gets in the body. Lymphatic system also contain immune cells and helps in microbe removal.
So the immune system is assisted by physical barrier, chemical barrier, and lymphatic system.
