Answer: we can make observations directly by seeing, feeling, hearing, and smelling, but we can also extend and refine our basic senses with tools: thermometers, microscopes, telescopes, radar, radiation sensors, X-ray crystallography, mass spectroscopy, etc. And these tools do a better job of observing than we can!
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Answer</h2>
The monosaccharides is formed by just bounding of C, H and O.
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Explanation</h2>
Monosaccharides are simplest molecule or unit in the carbohydrates group which united with each other to form di, tri or polysaccharide structure. As these are the simplest unit in carbohydrates, they are only formed by numbers of carbon, oxygen and hydrogen atoms. The number of atoms in the chain of monosaccharides varies with changing required compound. for example in deoxyribose, one of hydrogen is not present in its structure but present in ribose.
Answer: B and D
Explanation: We can break down why the correct answers are choices B and D by understanding why A and C are incorrect.
Option A states that active transport utilizes channel proteins, and facilitated diffusion utilizes carrier proteins. This is incorrect. Active transport involves carrier proteins, and facilitated diffusion involves channel proteins. Carrier proteins are different from channel proteins in that, while channel proteins can only facilitate the passive diffusion of ions into or out of the cell along their concentration gradient, carrier proteins can also use ATP to move ions in or out of the cell against their concentration gradient.
This brings us to why option C is also incorrect. Option C states that both processes require the input of energy in the form of ATP. While active transport requires the use of ATP to transport ions with or against their concentration gradient, facilitated diffusion does not. This is easily remembered when we consider that active transport is called *active* transport because the cell is *actively* using energy to transport ions.
Hope this helped.
The study of tree rings is called dendrochronology. Trees produce a single growth ring each year and by studying the size and composition of each ring scientists can get information about the age of the tree, available nutrients in the area, and general climatic conditions. A relatively small ring may indicate a year when there was very little rainfall and a larger ring indicates favourable conditions for plant growth.
Ice cores hold information on past global volcanic activity and past atmospheric conditions. Tiny bubbles in the ice cores give information on the concentration of gases in the atmosphere. Ice core data plays a key role in linking the increase in carbon dioxide concentrations to present day global warming.
