The five main external factors that must be present or provided t sustain life are:
1. Water
2. Oxygen
3. Food
4. Atmospheric temperature
5. Atmospheric pressure
<span>The human body needs water, food and oxygen in order the body functions to work properly.
</span>Not every temperature is temperature at which the human can live. For example: we can not stay alive long period of time at temperature of 60 degrees Celsius.
The second answer
Temperatures up high need to be warmer near the surface, surface air needs to be humid
Answer:
2nd one is the most realistic of what occurs in ecosyystems
Answer:
If both parents do not have sickle-cell anemia, than the possibility is low.
Explanation:
If both parents have the sickle-cell trait, their offspring has a 25 percent chance of getting sickle cell anemia and a 50 percent risk of them having sickle cell trait. Meanwhile, there is also a 25 percent chance of the child not getting it at all.
If one parent has sickle cell anemia and the other has sickle cell trait, then their offspring with have a 50 percent chance of getting sickle cell anemia and a 50 percent chance of getting a sickle cell trait.
When both parents have sickle cell anemia, their child will definitely have it.