The *heart* is the main organ of the circulatory system.
The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The system is responsible for the flow of blood, nutrients, oxygen and other gases, and as well as hormones to and from cells.
<span>Most people's urine is darker in the morning as the kidneys work hard during the night to remove impurities and the urine is more concentrated.</span>
Answer:
to reproduce it's offspring
Answer;
Endocytosis process
The vesicular process involved in the toxin entering the neuron is endocytosis process.
Explanation;
Endocytosis is a vesicular process, that involves capturing a particle or a substance from the outside of a cell by engulfing it with the cell membrane, and bringing it into the cell.
Botulinum toxin binds to the neuronal cell membranes at the nerve terminus and enters the neuron by endocytosis.
B) The positive charge of the protons in the nucleus equals the negative charge in the electron cloud.
(I just took the test and it was right). :)
