<span>The mitochondria in eukaryotic cells originated from prokaryotic cells, bacteria that were once free-living. The mitochondria have their own DNA, which is inherited from the mother in most species. Similarly, plant cells have organelles called plastids which contain their own DNA and originated from free-living bacteria. The chloroplasts in plant cells, which convert the energy of sunlight into chemical energy via photosynthesis, are a kind of plastid, and they originated from bacteria that could do photosynthesis.</span>
D. Calcium cycle
Biogeochemical cycles are not an important part of the Earth system.
Answer:
The answer is.. D. Brain :)
Reasoning:
Your brain stores info, allows you to get knowledge, process and think, including some responses such as sight, touch, hearing, and scents, and even things such as breathing, digestion, and much more. Your brain helps your heart keep pumping blood, gives control to muscles, and includes your memory.
