<span>4 molecules of oxygen. Haemoglobin is a protein found in the red blood cells, which carries oxygen to the cells to perform cellular respiration. Each red blood cell carries around 250 million haemoglobin. So the entire capacity of an RBC is around 1 billion oxygen molecules.</span>
It's B, Most them can make or produce their own food.
D nucleotides. which have nitrogen, carbon and a phosphate group
They are dangerous to the environment because they have no natural competition. That being said they have nothing to keep their population in check, therefore, taking away food, and habits from all the other species. Thus, causing species to die out, which in turn ruins the food chain.