The earth is a unique planet in that it is covered by more than 70 percent water. there are several properties of water that make earth a suitable environment for life, including how the density of solid water (ice) is about nine percent less than the density of liquid water. which best explains why this feature of water is important for marine life?
ice forms from the bottom of the water column up, allowing organisms to freeze and enter hibernation.
ice forms from the top of the water column down, creating a protective barrier over the liquid water.
the higher-density liquid water shelters organisms from cold air better than the less-dense ice.
the higher-density liquid water traps nutrients for primary producers better than the less-dense ice.
scientists have been studying threats to coral reefs. some reefs around the southeast shore of australia have experienced increased threats while others in the northwest shore of australia have seen a decrease in threat. explain the most effective way that scientists could use this information to design a new study aimed at developing reef protections.
scientists could compare environmental conditions in the threatened australian reefs with other reefs near florida, since there would be little overlap in their characteristics.
scientists could compare environmental conditions in the two sets of australian reefs, because those reefs are more likely to be similar in many ways. this will highlight the difference that is causing the threat.
scientists could compare environmental conditions in two sets of reefs in florida and apply that data to the reefs in australia.
scientists could compare environmental conditions in reefs randomly selected from around the world to get the most variable set of conditions possible and to make good comparisons.