Answer the following question given this paragraph: Cratonic rocks contain rounded sedimentary grains. Rounded grains indicate that the minerals eroded from an earlier rock. It also means that rivers or seas existed. Q: Rounded grains indicate that the minerals eroded from what? Choices: - iron - fossils - recent rock - earlier rock A:
earlier rock
Answer the following question given this paragraph: Q: During diastole, what happens to the elastic walls of the arteries? Choices: - they expand - they become hardened - they evolve - they snap back A:
they snap back
Q: Answer the following question given this paragraph: Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure below shows how peristalsis works. Q: What do the muscles of the gastrointestinal tract do? Choices: - break down food - secrete stomach acid - stop digestion - keep food moving A:
A: keep food moving
Question: Answer the following question given this paragraph: Unlike ethers, esters have a carbonyl group. Unlike carboxylic acids, esters have no acidic hydrogen atom; they have a hydrocarbon group in its place. Q: Carboxylic acids have an acidic hydrogen atom, but esters do not. what do esters have in place of an acidic hydrogen atom? Choices: - synthesis group - carbonation group - crystallization group - hydrocarbon group A:
Answer: hydrocarbon group
*Question*
Answer the following question given this paragraph: The first vertebrates evolved about 550 million years ago. The evolution of amphibians, reptiles, mammals, and birds occurred over the next 400 million years. The first vertebrates were ectotherms; endothermy evolved later. Modern fish, amphibians, and reptiles are ectotherms. Modern birds and mammals are endotherms. Q: Vertebrates differ from invertebrates because they lack this? Choices: - legs - head - neck - backbone or a spinal column A:
**Answer**
backbone or a spinal column
Q: Answer the following question given this paragraph: 1.5 Homeostasis Homeostasis is the activity of cells throughout the body to maintain the physiological state within a narrow range that is compatible with life. Homeostasis is regulated by negative feedback loops and, much less frequently, by positive feedback loops. Both have the same components of a stimulus, sensor, control center, and effector; however, negative feedback loops work to prevent an excessive response to the stimulus, whereas positive feedback loops intensify the response until an end point is reached. Q: What intensifies the response during homeostasis? Choices: - pressure loops - pure loops - negative feedback loops - positive feedback loops A:
A: positive feedback loops