Answer the following question given this paragraph: The enzyme pepsin works only in the presence of acid. A strong acid is secreted into the stomach. It provides the acid that pepsin needs. You will learn about acids in the next chapter, "Chemistry of Solutions. " Vinegar and lemon juice are two common acids. Q: The enzyme pepsin works only in the presence of what? Choices: - carbohydrates - sodium - oxygen - acid A:
acid
Answer the following question given this paragraph: Q: Contour tillage helps slow water run-off and what process that causes topsoil loss? Choices: - water erosion - ice shelf erosion - plate tectonics - soil erosion A:
soil erosion
Q: Answer the following question given this paragraph: The digestive system has three main functions: digestion of food, absorption of nutrients, and elimination of solid food waste. Digestion is the process of breaking down food into components the body can absorb. It consists of two types of processes: mechanical digestion and chemical digestion. Q: What is the process of breaking down food into components the body can absorb called? Choices: - absorption - filtration - excretion - digestion A:
A: digestion
Question: Answer the following question given this paragraph: Q: What cannot exist between energy levels? Choices: - crystals - protons - cells - electrons A:
Answer: electrons
*Question*
Answer the following question given this paragraph: A community is made up of the relationships between groups of different species. For example, the desert communities consist of rabbits, coyotes, snakes, birds, mice and such plants as sahuaro cactus, ocotillo, and creosote bush. Community structure can be disturbed by such dynamics as fire, human activity, and over-population. Q: The relationships between groups of different species makes up a ___________. Choices: - species - family - food chain - community A:
**Answer**
community
(Question)
Answer the following question given this paragraph: repeating bony units that make up the vertebral column of vertebrates. Q: What do vertebrates possess that is made up of repeating bony units? Choices: - notochord - skull - spinal cord - vertebral column A:
(Answer)
vertebral column