Q: Which protein, that stores oxygen in muscle cells, has been purified from a number of organisms? Read this paragraph and choose the correct option from the provided answers: Myoglobin, a protein that stores oxygen in muscle cells, has been purified from a number of organisms. The protein from a sperm whale is composed of 153 amino acid units. What is the minimum number of nucleotides that must be present in the mRNA that codes for this protein?. Choices: - melanin - potassium - iodine - myoglobin A:
myoglobin

Q: Where are some of the greatest concentrations of species found? Read this paragraph and choose the correct option from the provided answers: 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? Read this paragraph and choose the correct option from the provided answers: Helium has long been used in balloons and blimps. Since it is much less dense than air, it will float above the ground. We can buy small balloons filled with helium at stores, but large ones (such as the balloon seen above) are much more expensive and take up a lot more helium. 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? Read this paragraph and choose the correct option from the provided answers: Perhaps the most familiar liquid-solid solution is dental amalgam, used to fill teeth when there is a cavity. Approximately 50% of the amalgam material is liquid mercury to which a powdered alloy of silver, tin and copper is added. Mercury is used because it binds well with the solid metal alloy. However, the use of mercury-based dental amalgam has gone under question in recent years because of concerns regarding the toxicity of mercury. Choices: - the expense - the oxygen - the variability - the toxicity A:
the toxicity