Answer the following question given this paragraph: Convection is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earth's surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a convection current, like the one in Figure below . Convection is the most important way that heat travels in the atmosphere. Q: What is the transfer of heat by a current? Choices: - radiation - combustion - diffusion - convection A:
convection
Answer the following question given this paragraph: Did you ever see workers sandblasting a building to clean it? Sand is blown onto the surface to scour away dirt and debris. Wind-blown sand has the same effect. It scours and polishes rocks and other surfaces. Wind-blown sand may carve rocks into interesting shapes ( Figure below ). This form of erosion is called abrasion. It occurs any time rough sediments are blown or dragged over surfaces. Can you think of other ways abrasion might occur?. Q: Sandblasting a surface exemplifies what form of erosion? Choices: - wind - glacial - water - abrasion A:
abrasion
Q: Answer the following question given this paragraph: Q: Overharvesting is especially challenging for species with what type of habitat? Choices: - tundra - allowed - classified - restricted A:
A: restricted
Question: Answer the following question given this paragraph: Gases are less dense that either solids or liquids. Q: What is less dense then either solids or liquids? Choices: - plasma - ice - dark matter - gases A:
Answer: gases
*Question*
Answer the following question given this paragraph: View an animation (http://openstaxcollege. org/l/hexokinase2) of induced fit. When an enzyme binds its substrate, an enzyme-substrate complex is formed. This complex lowers the activation energy of the reaction and promotes its rapid progression in one of multiple possible ways. On a basic level, enzymes promote chemical reactions that involve more than one substrate by bringing the substrates together in an optimal orientation for reaction. Another way in which enzymes promote the reaction of their substrates is by creating an optimal environment within the active site for the reaction to occur. The chemical properties that emerge from the particular arrangement of amino acid R groups within an active site create the perfect environment for an enzyme's specific substrates to react. The enzyme-substrate complex can also lower activation energy by compromising the bond structure so that it is easier to break. Finally, enzymes can also lower activation energies by taking part in the chemical reaction itself. In these cases, it is important to remember that the enzyme will always return to its original state by the completion of the reaction. One of the hallmark properties of enzymes is that they remain ultimately unchanged by the reactions they catalyze. After an enzyme has catalyzed a reaction, it releases its product(s) and can catalyze a new reaction. Q: What is formed when an enzyme binds its substrate? Choices: - vessel - substrate complex - nucleus - substrate complex - lock and key model - enzyme - substrate complex A:
**Answer**
enzyme - substrate complex
(Q).
Answer the following question given this paragraph: hollow, sac-like organ that stores urine until it is excreted from the body. Q: What is the hollow sac like organ that stores urine until it is excreted? Choices: - kidney - ureter - tumor - bladder A:
(A).
bladder