<span>Activation energy refers to the amount of energy required by certain chemicals for them to have a reaction.
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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>
Clostridium, Bacteroides, and the methane-producing archaea (methanogens), are called obligate anaerobes because their energy-generating metabolic processes are not coupled with the consumption of oxygen.
I believe it is either B or A, personally i'm leaning towards B, but at the same time, i don't think that we would be obtaining materials via pollination, so it then causes A to make more sense.
Answer:
It is true that one-toed horse of today steadily evolved from its five-toed ancestor.
Explanation:
- Evolution is the law of nature.There is a continuous process of evolution in each biological species in nature.
- Similarly, horses had 5 toes millions of year back, but according to the theory of gradualism their use decreased and toes started fusing.
- Now, its only one toe at present but the vestigial left over provides the solid evidence for the fact that horses had 5 toes in the past.