Answer the following question given this paragraph: Air temperature in the stratosphere layer increases with altitude. Why? The stratosphere gets most of its heat from the Sun. Therefore, it's warmer closer to the Sun. The air at the bottom of the stratosphere is cold. The cold air is dense, so it doesn't rise. As a result, there is little mixing of air in this layer. Q: Where does the stratosphere get most of its heat? Choices: - time - earth - volcanoes - sun A:
sun
(Question)
Answer the following question given this paragraph: Alveoli are tiny sacs in the lungs where gas exchange takes place. Q: What are the tiny sacs in the lungs where gas exchange takes place? Choices: - bronchi - ganglion - cilia - alveoli A:
(Answer)
alveoli
Ques: Answer the following question given this paragraph: Some animals change their depth by changing their density. Recall that things that are denser than their surroundings sink while those that are less dense than their surroundings float. Most fish have a swim bladder, a special sac that is filled with gases from their blood. When the fish's swim bladder is full, it is less dense than the surrounding water and the fish will rise towards the surface. Another property of water that affects lakes is the unique changes in density during phase changes. The density of most substances increases when a liquid becomes a solid. This is not so for water: Solid water is actually less dense than liquid water. It is for this reason that ice floats. Can you imagine a world where ice sank? Lakes would freeze from the bottom up, killing many fish. Frozen water in the Polar Regions would sink and change the ocean levels. The fact that ice floats is essential for the survival of many aquatic ecosystems and ultimately life on Earth. Besides the changes in density, there are other ways in which the phase changes of water have significant impacts. When water is trapped in small cracks in rocks, it will expand as it freezes and break up the rock causing weathering. The transpiration (evaporation) of water from a good-sized tree can move 1800 liters of water out of the ground in a single day. Sublimation, the phase change between solid and gas, is responsible for the formation of frost. As you can see, water has many special properties that make its role in nature unique. It is considered the "universal solvent" because its bipolar molecule enables it to dissolve a wide variety of substances. Water is the only substance that occurs naturally in all three states; solid, liquid, and gas. Water is truly a miracle for life!. Q: How do some animals change their depth? Choices: - mass migration - metamorphosis - spontaneous mutations - by changing their density A:
Ans: by changing their density
(Q).
Answer the following question given this paragraph: Gas Exchange across the Alveoli In the body, oxygen is used by cells of the body's tissues and carbon dioxide is produced as a waste product. The ratio of carbon dioxide production to oxygen consumption is the respiratory quotient (RQ). RQ varies between 0.7 and 1.0. If just glucose were used to fuel the body, the RQ would equal one. One mole of carbon dioxide would be produced for every mole of oxygen consumed. Glucose, however, is not the only fuel for the body. Protein and fat are also used as fuels for the body. Because of this, less carbon dioxide is produced than oxygen is consumed and the RQ is, on average, about 0.7 for fat and about 0.8 for protein. The RQ is used to calculate the partial pressure of oxygen in the alveolar spaces within the lung, the alveolar PO Above, 2 the partial pressure of oxygen in the lungs was calculated to be 150 mm Hg. However, lungs never fully deflate with an exhalation; therefore, the inspired air mixes with this residual air and lowers the partial pressure of oxygen within the alveoli. This means that there is a lower concentration of oxygen in the lungs than is found in the air outside the body. Knowing the RQ, the partial pressure of oxygen in the alveoli can be calculated:. Q: In the body, oxygen is used by cells of the body's tissues and carbon dioxide is produced as what? Choices: - oxygen - fuel - food - waste product A:
(A).
waste product
Ques:Answer the following question given this paragraph: Names of ionic compounds are derived from the names of the ions, with the name of the cation coming first, followed by the name of the anion. If an element can form cations of different charges, there are two alternate systems for indicating the compound's name. In the Stock system, a roman numeral in parentheses indicates the charge on the cation. An example is the name for FeCl2, which is iron(II) chloride. In the common system, the suffixes -ous and -ic are used to stand for the lower and higher possible charge of the cation, respectively. These suffixes are attached to a stem representing the element (which frequently comes from the Latin form of the element name). An example is the common name for FeCl2, which is ferrous chloride. The formula mass of an ionic compound is the sum of the masses of each individual atom in the formula. Care must be taken when calculating formula masses for formulas containing multiple polyatomic ions because the subscript outside the parentheses refers to all the atoms in the polyatomic ion. Q: The name of the cation comes first, followed by the name of the anion, in what kind of compound? Choices: - magnetic compound - localized compound - covalent bonds - ionic compound A:

Ans:ionic compound
Ques: Answer the following question given this paragraph: Xylem and phloem are the two types of vascular tissues in vascular plants. Q: What are the two types of vascular tissues found in vascular plants? Choices: - xylem and chloroplasm - cytoplasm and chloroplasm - ectoderm and phloem - xylem and phloem A:
Ans:
xylem and phloem