Yes it is necessary for the production of apt in your cells because apt needs oxygen to form correctly.
Answer:
Explanation:
It is called a double circulatory system because blood passes through the heart twice per circuit. The right pump sends deoxygenated blood to the lungs where it becomes oxygenated and returns back to the heart. The left pump sends the newly oxygenated blood around the body.
When you compare different organisms and see that they have the same or similar anatomic traits, it's reasonable to assume the organisms share a common ancestor where they would have gotten trait from. (evolution)
Answer:
The answer is hormones.
Explanation:
Two of the main systems that control almost every action in our body are our nervous system and endocrine system which have to have inner communications and communication with our brain.
As stated in the question, nervous system uses neurotransmitters for communication which are chemicals released by neurons to generate electrical signals that make the communication possible.
The main mean of communication that our endocrine system uses is substances that are called "Hormones" which are produced by certain glands and organs in our body and are usually released into our bloodstream to effect the functions of other organs and our body. Hormones can be used for both communication of the endocrine system itself and for the communication of other organs and our brain.
I hope this answer helps.