Gases in Earth's Atmosphere. Nitrogen and Oxygen are by far the most common. Dry air is composed of about 78% Nitrogen (N2) and about 21% Oxygen (O2). Argon, Carbon Dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases.
So therefore Oxygen is the gas that makes up the largest portion of the Earths Atmosphere.
The control group is the part of an experiment that does not receive the variable and is used for comparison.
Answer:
- Respiratory system
- Nervous system
- Circulatory system
- Integumentary system
- Endocrine system
Explanation:
During excessive hard work or sports, the respiratory system acts to provide sufficient oxygen for energy supply (ATP) - a process takes place in mitochondria. At the very beginning, the respiratory system is active. If the person doesn't intake sufficient water, he will feel tired because of heavy breathing that increases body temperature and affects metabolic reactions. A supply of water would help decrease the respiration need and so support other systems.
The nervous system (hypothalamus) regulates the body temperature which is necessary for metabolic reactions taking place within the body, i.e. homeostasis. During and after exercise, the water intake was not sufficient, this means that the hypothalamus would work to maintain the temperature as well as other metabolic mechanisms. In the case of less water intake, the nervous system would be in stress.
The circulatory system acts to transport blood and oxygen to all parts of the body. During sports activities, the oxygen supply would be high to maintain energy supply. This takes place with the combined action of the circulatory system and respiratory system. For optimal functioning, the circulatory system needs fluids (water) intake because sufficient water is already lost during sports.
The integumentary system is the system that directly protects the body from damages including dehydration. Therefore, in this case, it will be highly active.
The endocrine system consists of glands that produce hormones to control body metabolism. The body metabolism, as mentioned before, is driven through water availability. The reduced water in the body would also put the endocrine system under pressure.
A neurotransmitter can have an excitatory or inhibitory effect on the postsynaptic cell, depending on <u>which of its </u><u>receptor(s</u><u>) are present on the </u><u>postsynaptic</u><u> (target) cell.</u>
<h3>How do excitatory and inhibitory neurotransmitters act?</h3>
Sometimes neurotransmitters can bind to receptors and cause an electrical signal to be transmitted through the cell (excitatory). In other cases, the neurotransmitter can prevent the signal from continuing, preventing the message from being carried (inhibitory).
With this information, we can conclude that a neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse.
Learn more about neurotransmitter in brainly.com/question/9725469
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