<span>A.
to fuel their chemical reactions</span>
It is called a Double Helix.
Answer:
C
Explanation:
You need to start with the simplest form and go to the most complex,
Small clump of cells -> having structure -> Basic feathers -> Yassificated feathers
Your cardiovascular system is made up of the heart and blood vessels (arteries, capillaries, veins).
Answer:
Mammals, insects, fish and plants all have different systems of exchanging gas. For mammals we breathe into our lungs, for fish they use gills and insects use spiracles.
Explanation:
hope it kind of helps sorry if it doesn't
