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: Where are some of the greatest concentrations of species found? Choices: - at high altitudes - in the arctic - in mould colonies - in the tropics A:
in the tropics

Q: What sort of gas is found in balloons and blimps, and is used to make them float in the sky? Choices: - oxygen - hydrogen - radon - helium A:
helium

Q: The use of mercury-based dental amalgam has gone under question in recent years because of concerns regarding what? Choices: - the expense - the oxygen - the variability - the toxicity A:
the toxicity