pH.D.
Clue: A compound that releases hydrogen ions (H+) in solution and has a pH of less than 7.
Answer: What is an acid?
Clue: A compound made of carbon, hydrogen, and oxygen that is a main source of energy for the body.
Answer: What is a carbohydrate?
Clue: The process that changes or transforms one set of chemicals into another set of chemicals.
Answer: What is a chemical reaction?
Clue: The scientific study of interactions among organisms and between organisms and their environment.
Answer: What is ecology?
Clue: A living part of an environment is one type of factor, while a physical or nonliving part is another. Name both types.
Answer: What are biotic factors and abiotic factors?
Clue: A compound that releases hydroxide ions (OH-) in solution and has a pH of more than 7.
Answer: What is a base?
Clue: Fats, oils, and waxes belong to this group of macromolecules.
Answer: What are lipids?
Clue: The energy needed to get a reaction started.
Answer: What is activation energy?
Clue: A group of individuals of the same species that live in the same area.
Answer: What is a population?
Clue: An organism that captures energy from sunlight or chemicals and produces its own food is called this. It is also called a producer.
Answer: What is an autotroph?
Clue: A compound that prevents sharp, sudden changes in pH.
Answer: What is a buffer?
Clue: This macromolecule contains hydrogen, oxygen, nitrogen, carbon, and phosphorus.
Answer: What is a nucleic acid?
Clue: A substance that speeds up the rate of a chemical reaction.
Answer: What is a catalyst?
Clue: A group of different populations that live together in a defined area.
Answer: What is a community?
Clue: An organism that obtains food by consuming other living things is called this. It is also called a consumer.
Answer: What is a heterotroph?
Clue: One solution has a pH of 4 and another has a pH of 9. Classify each solution as an acid or a base.
Answer: The pH 4 solution is an acid. The pH 9 solution is a base.
Clue: This macromolecule contains carbon, hydrogen, oxygen, and nitrogen and is needed by the body for growth and repair.
Answer: What is a protein?
Clue: A protein catalyst that speeds up the rate of specific biological reactions.
Answer: What is an enzyme?
Clue: All the organisms that live in a place together with their physical environment.
Answer: What is an ecosystem?
Clue: One of these shows a series of steps through which organisms transfer energy by eating and being eaten, while the other shows a network of feeding relationships. Name both.
Answer: What are a food chain and a food web?
Clue: An organism must maintain a relatively stable internal pH. A substance prevents its pH from changing sharply when acid is introduced. What type of substance is doing this, and why is this important?
Answer: It is a buffer. Buffers prevent sharp changes in pH and help maintain stable internal conditions.
Clue: A student says, "Proteins and amino acids are the same thing." Explain the relationship between proteins and amino acids.
Answer: Amino acids are compounds that join together to form proteins. Proteins are macromolecules built from amino acids.
Clue: A chemical reaction inside a cell normally occurs too slowly to support life. Explain how an enzyme helps the reaction occur faster.
Answer: The enzyme acts as a catalyst and lowers the activation energy needed for the reaction, allowing the reaction to occur more quickly.
Clue: Put these levels of ecological organization in order from smallest to largest: biosphere, biome, ecosystem, population, community.
Answer: Population → Community → Ecosystem → Biome → Biosphere
Clue: Grass → grasshopper → frog → snake. Each step represents a trophic level. Explain what happens to the available energy as you move toward the snake and how an ecological pyramid represents this relationship.
Answer: The amount of available energy decreases at higher trophic levels. An ecological pyramid shows this by becoming smaller toward the top.