When rocks are altered by high heat and pressure deep in the Earth, they undergo metamorphism and become metamorphic rocks. This process rearranges minerals and often changes texture without melting, producing rocks that may have a layered (foliated) appearance or a more uniform texture. That’s exactly the scenario described—existing rocks changing form under heat and pressure. Shale can become slate, limestone can become marble, and granite can become gneiss, illustrating how the same original material can transform into different metamorphic forms under these conditions. Sedimentary rocks form from sediments that settle and are cemented together, so they aren’t defined by heat and pressure changing existing rocks. Igneous rocks form from molten rock that cools and solidifies, a different process altogether. Limestone is an example of a sedimentary rock (made largely of calcium carbonate), though it can become marble if subjected to metamorphism.

Preserving biodiversity based on both intrinsic and utilitarian value means recognizing that species exist for their own sake and also provide essential benefits to ecosystems and people. Intrinsic value is the idea that living beings have worth independent of how useful they might be. Utilitarian value, or ecosystem services, includes pollination, nutrient cycling, water purification, climate regulation, and cultural or recreational benefits. The best statement combines these ideas, saying biodiversity exists for its own sake and provides ecosystem services, and should be preserved. This dual view explains why protecting biodiversity matters: we respect the right of species to exist while also recognizing the practical benefits their diversity provides, like crops that depend on pollinators, forests that store carbon, and ecosystems that recover better from disturbances.

Convection is the process at work. When air is heated near a heat source, it becomes less dense than the surrounding cooler air, so it rises. As it rises, it cools, becomes denser, and sinks, creating a circular pattern called a convection current. In a room, this means warm air from a heater tends to rise toward the ceiling while cooler air moves in to take its place, sustaining the circulation. Conduction would transfer heat mainly by direct contact, warming nearby surfaces or air without creating the rising movement. Radiation transfers heat through waves from the source to objects, and doesn’t by itself describe the vertical rise of air. Reflection is just the bouncing of waves and isn’t a heat-transfer mechanism in this context.

A hypothesis is an educated, testable prediction about how changing one thing will affect another. It usually links the variable you change (the independent variable) with the outcome you measure (the dependent variable) and is often written as an If/Then statement: If I change the independent variable, then the dependent variable will respond in a certain way, because of what I know about the system. This uses background knowledge and prior observations to make a claim you can check with experiments. It's not just a guess or the data you collect, and it's not the conclusion you reach after analyzing results. This kind of statement is exactly what a hypothesis is.