Q: Which protein, that stores oxygen in muscle cells, has been purified from a number of organisms? Choices: - melanin - potassium - iodine - myoglobin A:
myoglobin

Q: What were the first photosynthetic organisms on earth? Choices: - mosses - trees - fungi - bacteria A:
bacteria

Q: Reducing the production of what gas, or removing it from the air, are practices that could reduce global warming? Choices: - helium - hydrogen - oxygen - carbon dioxide A:
carbon dioxide