Do you need specific sources on this for a paper? I️ would use easybib it is a great source to get bibliographies done quick.
Answer:
a.energy source ,either sunlight or chemicals
Explanation:
the animals using sunlight are known as photoautotrophs and the animals using chemicals are known as chemoautotrophs.
It is like a barrier, or wall. It helps infection and bacteria stay out. It can also help you indicate whether you are getting infection in the inside of your body. if you're skin is inflamed, that is a sign of disease or infection.
I hope this helped you!
Brainliest answer is always appreciated!<span />
Because that organism is really really small
