Answer:
<em>The correct option is d) once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.</em>
Explanation:
In the field of biology, the all-or-nothing law can be described as a principle which focuses on the strength with which a nerve or muscle fibre responds to a particular stimulus, this strength being independent of the strength of the stimulus. The functioning of the impulse is just like the trigger of a gun. The more the force of a stimulus, the more will be the intensity of the nerve impulse.
<span>Nervous tissue is specialised to react to stimulate and to conduct impulses to various organs in the body which bring about a response to the stimulus. Nerve tissue (as in the brain, spinal cord and peripheral nerves that branch throughout the body) are all made up of specialised nerve cells called neurons. Hope this helps! :D</span>
Answer: polyunsaturated fatty acid residues
Explanation: Unsaturated fatty acids have a lower melting point so arctic animals have these fatty acids in their membranes.
Answer:
Nervous system: This systems helps the five sense organs (eyes, ears, nose, tongue, skin) which all contain nerves that send messages to the brain about what is happening. The brain produces a response which it sends via other nerves to the muscles.
Digestive system: This system helps to break down food into simpler substances so it can be used and absorbed into the body. It takes place in the alimentary canal (food tube), mainly in the stomach and small intestine. The digested food is absorbed into the blood.
Respiratory System: This system helps take in oxygen and removing waste carbon dioxide. Air enters the lungs by movement of the rib muscles and diaphragm. The oxygen is absorbed into the blood.
Reproductive system: This helps produce offspring. Eggs are produces by ovaries in a female and the sperm is produced in the testes of a male. They then try and fertilise the eggs.
Note:
Hope this helped <33
Answer:
Since the industrial revolution, human activities have also resulted in an increase in natural greenhouse gases, especially carbon dioxide. An increase in these gases in the atmosphere enhances the atmosphere's ability to trap heat, which leads to an increase in the average surface temperature of the Earth.
Explanation:
