In humans, the maintenance of a stable internal temperature is a direct result of Homeostasis. Homeostasis is the ability of the body to maintain an equilibrium condition within it's internal environment even when dealing external changes. Homeostasis happens in human when there is an effort exerts by the body to regulate it's internal temperature around 98.6 degrees Fahrenheit. For example, during summer days we produce sweat for our body to cool off, and during winter we shiver for our body to produce heat.
Answer:
12
Explanation:
Suppose the four different strains are P, Q, R, S. Thus, the first infection can be from any of the four strains and it occurs in 4 ways.
Since an individual cannot be infected again with the strain from which he/she is been previously infected;
Then, at the second time;
The possible number of strain to be infected with = 4-1 = 3 ways
Thus; the number of possible different levels of severity can be viewed by forming two lettered word P, Q, R, and S without repetition which is:
= 4 × 3
= 12
C Fossils allow scientists to have an idea of the time scale that traits evolved.
The answer is a. the troposphere
