The essential amino acids cannot be produced in the human body and hence these amino acids have to be obtained through the diet. Hence these amino acids have this characteristic that these cannot be produced in the human body and have to be obtained through diet this makes them essential. Hence those nine amino acids are considered as the essential amino acids.
<span>The anterior end of an earthworm contains an organ that detects smells. Evidence of this is the way the earthworms responded to the ammonia. The earthworms backed away from the ammonia when it was waved near their anterior end, but they did not respond at all when the ammonia was waved near their posterior end.</span>
Answer:
Homeostasis is the process of maintaining a constant internal environment of the body with the help of certain mechanisms such as feedback loops.
Explanation:
Homeostasis refers to the maintenance of a relatively constant internal environment of the body. It includes maintaining several parameters such as acid-base balance, blood glucose level, body' temperature, etc. within the narrow range.
Homeostasis is mainly maintained with the help of negative feedback loops wherein the deviation of any parameter from the normal physiological range is counteracted and restored.
For example, the blood glucose level remains within the range of 70 and 110 milligrams of glucose per 100 milliliters of blood under normal physiological conditions. Any deviation from the range is restored with the help of pancreatic hormones insulin and glucagon.
The term that can be used to describe evolution by natural selection is SCIENTIFIC THEORY.
Theory means "the best explanation so far."
Scientific theory is a work in progress. It is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method, and repeatedly confirmed through observation and experimentation.