Q: What phenomenon sometimes causes harmful alleles to become fixed? Read this paragraph and choose the correct option from the provided answers: Choices: - natural selection - competition - spontaneous mutation - genetic drift A:
genetic drift

Q: Because the earth is covered with vegetation, cellulose is the most abundant of all what? Read this paragraph and choose the correct option from the provided answers: Cellulose Cellulose, a fibrous carbohydrate found in all plants, is the structural component of plant cell walls. Because the earth is covered with vegetation, cellulose is the most abundant of all carbohydrates, accounting for over 50% of all the carbon found in the vegetable kingdom. Cotton fibrils and filter paper are almost entirely cellulose (about 95%), wood is about 50% cellulose, and the dry weight of leaves is about 10%20% cellulose. The largest use of cellulose is in the manufacture of paper and paper products. Although the use of noncellulose synthetic fibers is increasing, rayon (made from cellulose) and cotton still account for over 70% of textile production. Like amylose, cellulose is a linear polymer of glucose. It differs, however, in that the glucose units are joined by -1,4-glycosidic linkages, producing a more extended structure than amylose (part (a) of Figure 16.11 "Cellulose"). This extreme linearity allows a great deal of hydrogen bonding between OH groups on adjacent chains, causing them to pack closely into fibers (part (b) of Figure 16.11 "Cellulose"). As a result, cellulose exhibits little interaction with water or any other solvent. Cotton and wood, for example, are completely insoluble in water and have considerable mechanical strength. Choices: - impurities - vegetables - rocks - carbohydrates A:
carbohydrates

Q: Q: Haumea, which is the third brightest kuiper belt object has an odd oval shape which is probably caused by what? Read this paragraph and choose the correct option from the provided answers: Haumea is the third-brightest Kuiper belt object. Haumea has two moons. Haumea's odd oval shape is probably caused by its extremely rapid rotation. It rotates in just less than 4 hours! Like other Kuiper belt objects, Haumea is covered by ice. Its density is similar to Earth's Moon, at 2.6 3.3 g/cm 3 . This means that most of Haumea is rocky. Choices: - unusually rapid rotation - particularly rapid rotation - Slow rotation - extremely rapid rotation A:
A: extremely rapid rotation

Question: Q: Which human body system is a complex network of nervous tissue that carries electrical messages throughout the body? Read this paragraph and choose the correct option from the provided answers: The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body. Its functions include controlling muscles, maintaining balance, sensing internal and external environments, controlling body systems to maintain homeostasis, preparing the body for emergencies, and allowing higher mental functions such as thinking. Choices: - the localized system - the lymph system - the bacterial system - the nervous system A:
Answer: the nervous system

*Question*
Q: What kind of power plant uses energy to heat water that becomes steam and spins turbines? Read this paragraph and choose the correct option from the provided answers: Nuclear power plants use the energy they produce to heat water. The water turns into steam, which causes a turbine to spin. This in turn produces electricity. Choices: - hydroelectric - coal - wind - nuclear power plants A:
**Answer**
nuclear power plants

*Question*
Q: What helps push the fetus from the uterus during birth? Read this paragraph and choose the correct option from the provided answers: Near the time of birth, the amniotic sac breaks in a gush of liquid. Labor usually begins within a day of this event. Labor involves contractions of the muscular walls of the uterus. With the mother's help, the contractions eventually push the fetus out of the uterus and through the vagina. Choices: - glands - tremors - Shaking - contractions A:
**Answer**
contractions