Answer the following question given this paragraph: All redox reactions occur with a simultaneous change in the oxidation numbers of some atoms. At least two elements must change their oxidation numbers. When an oxidation number of an atom is increased in the course of a redox reaction, that atom is being oxidized. When an oxidation number of an atom is decreased in the course of a redox reaction, that atom is being reduced. Thus oxidation and reduction can also be defined in terms of increasing or decreasing oxidation numbers, respectively. Saylor URL: http://www. saylor. org/books. Q: When an oxidation number of an atom is decreased in the course of a redox reaction, that atom is being what? Choices: - replaced - increased - destroyed - reduced A:
reduced
(Question)
Answer the following question given this paragraph: Energy is passed up a food chain or web from lower to higher trophic levels. However, generally only about 10 percent of the energy at one level is available to the next level. This is represented by the ecological pyramid in Figure below . What happens to the other 90 percent of energy? It is used for metabolic processes or given off to the environment as heat. This loss of energy explains why there are rarely more than four trophic levels in a food chain or web. Sometimes there may be a fifth trophic level, but usually there's not enough energy left to support any additional levels. Q: What are the "levels" in a food chain or web called? Choices: - parts - root - gauges - trophic A:
(Answer)
trophic
Ques: Answer the following question given this paragraph: An explosive eruption produces huge clouds of volcanic ash. Chunks of the volcano fly high into the atmosphere. Explosive eruptions can be tens of thousands of times as powerful as an atomic bomb ( Figure below ). Hot magma beneath the surface mixes with water. This forms gases. The gas pressure grows until it must be released. The volcano erupts in an enormous explosion. Q: Explosive eruptions associated with what can be tens of thousands of times as powerful as an atomic bomb? Choices: - forest fires - hurricanes - earthquakes - volcanoes A:
Ans: volcanoes
(Q).
Answer the following question given this paragraph: Binary fission occurs when a parent cell splits into two identical daughter cells of the same size. Q: What occurs when a parent cell splits into two identical daughter cells of the same size? Choices: - linear fission - symbiotic fission - twin fission - binary fission A:
(A).
binary fission
Ques:Answer the following question given this paragraph: Sometimes two air masses stop moving when they meet. These stalled air masses create a stationary front . Such a front may bring clouds and precipitation to the same area for many days. Q: What weather phenomenon, which may bring clouds and precipitation, is created by stalled air masses? Choices: - susceptible front - cool front - Horizontal Front - stationary front A:

Ans:stationary front
Ques: Answer the following question given this paragraph: 17.2 Hormones Hormones are derived from amino acids or lipids. Amine hormones originate from the amino acids tryptophan or tyrosine. Larger amino acid hormones include peptides and protein hormones. Steroid hormones are derived from cholesterol. Steroid hormones and thyroid hormone are lipid soluble. All other amino acidderived hormones are water soluble. Hydrophobic hormones are able to diffuse through the membrane and interact with an intracellular receptor. In contrast, hydrophilic hormones must interact with cell membrane receptors. These are typically associated with a G protein, which becomes activated when the hormone binds the receptor. This initiates a signaling cascade that involves a second messenger, such as cyclic adenosine monophosphate (cAMP). Second messenger systems greatly amplify the hormone signal, creating a broader, more efficient, and faster response. Hormones are released upon stimulation that is of either chemical or neural origin. Regulation of hormone release is primarily achieved through negative feedback. Various stimuli may cause the release of hormones, but there are three major types. Humoral stimuli are changes in ion or nutrient levels in the blood. Hormonal stimuli are changes in hormone levels that initiate or inhibit the secretion of another hormone. Finally, a neural stimulus occurs when a nerve impulse prompts the secretion or inhibition of a hormone. Q: What kind of hormones are derived from cholesterol? Choices: - germs - Antibiotic - synthesis - steroid A:
Ans:
steroid