Cell membrane... i believe this to be the correct answer
With the beginning of the middle proterozoic comes the first evidence of oxgen build up in the atmosphere. with is catastrophe came eukaryotic forms. these include multicellular algae, and toward the end of the proterozoic the first animals
Answer:
contains vitamin A
Explanation:
its essential for improving eyesight
Proteins
Carbohydrates
Lipids
Nucleic Acids
