Answer the following question given this paragraph: All objects in the universe have an attraction to each other. This attraction is known as gravity ( Figure below ). The strength of the force of gravity depends on two things. One is the mass of the objects. The other is the distance between the objects. As an object's mass increases, the attraction increases. As the distance between the objects increases, the attraction decreases. Q: The attraction between all objects in the universe is known as ______. Choices: - variation - electricity - magnetism - gravity A:
gravity
Answer the following question given this paragraph: Temperate Forests Temperate forests are the most common biome in eastern North America, Western Europe, Eastern Asia, Chile, and New Zealand (Figure 20.18). This biome is found throughout mid-latitude regions. Temperatures range between 30oC and 30oC (22oF to 86oF) and drop to below freezing on an annual basis. These temperatures mean that temperate forests have defined growing seasons during the spring, summer, and early fall. Precipitation is relatively constant throughout the year and ranges between 75 cm and 150 cm (29.559 in). Deciduous trees are the dominant plant in this biome with fewer evergreen conifers. Deciduous trees lose their leaves each fall and remain leafless in the winter. Thus, little photosynthesis occurs during the dormant winter period. Each spring, new leaves appear as temperature increases. Because of the dormant period, the net primary productivity of temperate forests is less than that of tropical rainforests. In addition, temperate forests show far less diversity of tree species than tropical rainforest biomes. The trees of the temperate forests leaf out and shade much of the ground; however, more sunlight reaches the ground in this biome than in tropical rainforests because trees in temperate forests do not grow as tall as the trees in tropical rainforests. The soils of the temperate forests are rich in inorganic and organic nutrients compared to tropical rainforests. This is because of the thick layer of leaf litter on forest floors and reduced leaching of nutrients by rainfall. As this leaf litter decays, nutrients are returned to the soil. The leaf litter also protects soil from erosion, insulates the ground, and provides habitats for invertebrates and their predators (Figure 20.24). Q: Which type of tree loses its leaves each fall and remains leafless in the winter? Choices: - perennial - conifer - annual - deciduous A:
deciduous
Q: Answer the following question given this paragraph: Two nuclei must collide for fusion to occur. High temperatures are required to give the nuclei enough kinetic energy to overcome the very strong repulsion resulting from their positive charges. A nuclear reactor consists of the following: 1. A nuclear fuel. A fissionable isotope must be present in large enough quantities to sustain a controlled chain reaction. The radioactive isotope is contained in tubes called fuel rods. A moderator. A moderator slows neutrons produced by nuclear reactions so that they can be absorbed by the fuel and cause additional nuclear reactions. A coolant. The coolant carries heat from the fission reaction to an external boiler and turbine where it is transformed into electricity. Q: What must two nuclei do for fusion to occur? Choices: - explode - melt - repel each other - collide A:
A: collide
Question: Answer the following question given this paragraph: Streams often start in mountains, where the land is very steep. You can see an example in Figure below . A mountain stream flows very quickly because of the steep slope. This causes a lot of erosion and very little deposition. The rapidly falling water digs down into the stream bed and makes it deeper. It carves a narrow, V-shaped channel. Q: Where do streams often start? Choices: - valleys - oceans - plains - mountains A:
Answer: mountains
*Question*
Answer the following question given this paragraph: Female Hormones The control of reproduction in females is more complex. The female reproductive cycle is divided into the ovarian cycle and the menstrual cycle. The ovarian cycle governs the preparation of endocrine tissues and release of eggs, while the menstrual cycle governs the preparation and maintenance of the uterine lining (Figure 18.17). These cycles are coordinated over a 2232 day cycle, with an average length of 28 days. As with the male, the GnRH from the hypothalamus causes the release of the hormones FSH and LH from the anterior pituitary. In addition, estrogen and progesterone are released from the developing follicles. As with testosterone in males, estrogen is responsible for the secondary sexual characteristics of females. These include breast development, flaring of the hips, and a shorter period for bone growth. The Ovarian Cycle and the Menstrual Cycle The ovarian and menstrual cycles are regulated by hormones of the hypothalamus, pituitary, and ovaries (Figure 18.17). The ebb and flow of the hormones causes the ovarian and menstrual cycles to advance. The ovarian and menstrual cycles occur concurrently. The first half of the ovarian cycle is the follicular phase. Slowly rising levels of FSH cause the growth of follicles on the surface of the ovary. This process prepares the egg for ovulation. As the follicles grow, they begin releasing estrogen. The first few days of this cycle coincide with menstruation or the sloughing off of the functional layer of the endometrium in the uterus. After about five days, estrogen levels rise and the menstrual cycle enters the proliferative phase. The endometrium begins to regrow, replacing the blood vessels and glands that deteriorated during the end of the last cycle. Q: What two cycles make up the female reproductive cycle? Choices: - ovarian and cesarean - cervical and menstrual - digestive and menstrual - ovarian and menstrual A:
**Answer**
ovarian and menstrual
Q: Answer the following question given this paragraph: After a mass extinction, many habitats are no longer inhabited by organisms because they have gone extinct. With new habitats available, some species will adapt to the new environments. Evolutionary processes act rapidly during these times. Many new species evolve to fill those available habitats. The process in which many new species evolve in a short period of time to fill available niches is called adaptive radiation . At the end of this period of rapid evolution, the life forms do not look much like the ones that were around before the mass extinction. One example came after the extinction of the dinosaurs. Mammals underwent adaptive radiation and became the dominant life form. Although they lived in the habitats the dinosaurs had lived in, they didn't look much like the dinosaurs. Q: What is the process in which many new species evolve in a short period of time to fill available niches called? Choices: - adaptation - learned behavior - spontaneous mutation - adaptive radiation A:
A: adaptive radiation