Hormones because if you think about it. Vertebrates must have backbones and mammals have them. And, humans are basically mammals. And the glands secrete hormones.
Answer:
The living organisms in an ecosystem can be divided into three categories: producers, consumers and decomposers. They are all important parts of an ecosystem. Producers are the green plants The third type of living organism in an ecosystem is the decomposers.
Explanation:
no
The answer is <span>The respiratory system supplies the oxygen that the cardiovascular system transports to the different cells for the production of energy.
When air enters the lungs (part of the respiratory system), it passes all way to the alveoli, the smallest functional units of the lung. There, oxygen from the air enters the capillaries, the smallest blood vessels, next to the alveoli. Once in the blood stream, the cardiovascular system transports oxygen to different cells where it is used for the energy production.</span>
The first stage of cellular respiration is glycolysis. It does not require oxygen. During glycolysis, one glucose molecule is split into two pyruvate molecules, using 2 ATP while producing 4 ATP and 2 NADH molecules.
