Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: Carbohydrates include sugars, starches, and fiber. Sugars and starches are used by the body for energy. One gram of sugar or starch provides 4 Calories of energy. Fiber doesn't provide energy, but it is needed for other uses. At age 13 years, you need about 130 grams of carbohydrates a day. Figure below shows good food sources of each type. Answer: 4

Answer: How many calories of energy does one gram of sugar or starch provide?

Question: Passage: CHAPTER SUMMARY 11.1 Discovering How Populations Change Evolution by natural selection arises from three conditions: individuals within a species vary, some of those variations are heritable, and organisms have more offspring than resources can support. The consequence is that individuals with relatively advantageous variations will be more likely to survive and have higher reproductive rates than those individuals with different traits. The advantageous traits will be passed on to offspring in greater proportion. Thus, the trait will have higher representation in the next and subsequent generations leading to genetic change in the population. The modern synthesis of evolutionary theory grew out of the reconciliation of Darwin's, Wallace's, and Mendel's thoughts on evolution and heredity. Population genetics is a theoretical framework for describing evolutionary change in populations through the change in allele frequencies. Population genetics defines evolution as a change in allele frequency over generations. In the absence of evolutionary forces allele frequencies will not change in a population; this is known as Hardy-Weinberg equilibrium principle. However, in all populations, mutation, natural selection, genetic drift, and migration act to change allele frequencies. Answer: population genetics

Answer: What is the term for a theoretical framework for describing evolutionary change in populations through the change in allele frequencies?

Question: Passage: View the University of Michigan WebScope at http://virtualslides. umich. edu/Histology/EMsmallCharts/ 3%20Image%20Scope%20finals/054%20-%20Peripheral%20nerve_001. svs/view. apml?listview=1& (http://openstaxcollege. org/l/nervefiber) to see an electron micrograph of a cross-section of a myelinated nerve fiber. The axon contains microtubules and neurofilaments that are bounded by a plasma membrane known as the axolemma. Outside the plasma membrane of the axon is the myelin sheath, which is composed of the tightly wrapped plasma membrane of a Schwann cell. What aspects of the cells in this image react with the stain to make them a deep, dark, black color, such as the multiple layers that are the myelin sheath?. Answer: axolemma

Answer:
The axon contains microtubules and neurofilaments that are bounded by a plasma membrane known as what?