Some reasons:
→ They're cheap and common animals.
→ They can be either a source of meat, skin (leather) or milk.
→ Farmers benefit a lot with them, since what they produce are things of everyday consumption.
→ You don't need to spend much to be able to have them (mostly only with land).
Hope it helped,
BioTeacher101
Lack of vitamin D has been linked to increased risk for autoimmune diseases.
Hope that helped you.
The cell wall and chlorophyll are not found in animal cells.
Hope this helps!
-Payshence
Density= mass/volume
volume=mass/density
mass= volume•density
Answer and Explanation: The excretory system helps the respiratory system by getting rid of carbon dioxide. The respiratory system helps the excretory system by getting rid of CO2 from the body. They both need each other and if one or the other did not exist, we might've not been able to survive. Tis demonstrates how vital they are for the human body.