Answer the following question given this paragraph: Protists are eukaryotes in the Protist Kingdom. Most are single-celled organisms. Protists are thought to be the oldest eukaryotes. They probably evolved when some prokaryotic cells invaded or were engulfed by others. Q: What is thought to be the oldest eukaryotes? Choices: - amoebas - prokaryotes - arthropods - protists A:
protists
(Question)
Answer the following question given this paragraph: Using Prokaryotes to Clean up Our Planet: Bioremediation Microbial bioremediation is the use of prokaryotes (or microbial metabolism) to remove pollutants. Bioremediation has been used to remove agricultural chemicals (pesticides and fertilizers) that leach from soil into groundwater. Certain toxic metals, such as selenium and arsenic compounds, can also be removed from water by bioremediation. The reduction of SeO 24 to SeO 23 and to Se0 (metallic selenium) is a method used to remove selenium ions from water. Mercury is an example of a toxic metal that can be removed from an environment by bioremediation. Mercury is an active ingredient of some pesticides; it is used in industry and is also a byproduct of certain industries, such as battery production. Mercury is usually present in very low concentrations in natural environments but it is highly toxic because it accumulates in living tissues. Several species of bacteria can carry out the biotransformation of toxic mercury into nontoxic forms. These bacteria, such as Pseudomonas aeruginosa, can convert Hg2+ to Hg0, which is nontoxic to humans. Probably one of the most useful and interesting examples of the use of prokaryotes for bioremediation purposes is the cleanup of oil spills. The importance of prokaryotes to petroleum bioremediation has been demonstrated in several oil spills in recent years, such as the Exxon Valdez spill in Alaska (1989) (Figure 13.10), the Prestige oil spill in Spain (2002), the spill into the Mediterranean from a Lebanon power plant (2006,) and more recently, the BP oil spill in the Gulf of Mexico (2010). To clean up these spills, bioremediation is promoted by adding inorganic nutrients that help bacteria already present in the environment to grow. Hydrocarbon-degrading bacteria feed on the hydrocarbons in the oil droplet, breaking them into inorganic compounds. Some species, such as Alcanivorax borkumensis, produce surfactants that solubilize the oil, while other bacteria degrade the oil into carbon dioxide. In the case of oil... Q: Use of oil-consuming bacteria to clean up an oil spill is an example of what? Choices: - generation - coagulation - biodegradation - bioremediation A:
(Answer)
bioremediation
Ques: Answer the following question given this paragraph: Earth is spinning as air moves over its surface. This causes the Coriolis effect. Winds blow on a diagonal over the surface due to Coriolis effect. From which direction do the northern trade winds blow?. Q: Earth spinning as air moves over its surface causes what? Choices: - seasons - centrifugal effect - axial tilt - coriolis effect A:
Ans: coriolis effect
(Q).
Answer the following question given this paragraph: Why must hadrons be white? The color scheme is intentionally devised to explain why baryons have three quarks and mesons have a quark and an antiquark. Quark color is thought to be similar to charge, but with more values. An ion, by analogy, exerts much stronger forces than a neutral molecule. When the color of a combination of quarks is white, it is like a neutral atom. The forces a white particle exerts are like the polarization forces in molecules, but in hadrons these leftovers are the strong nuclear force. When a combination of quarks has color other than white, it exerts extremely large forceseven larger than the strong forceand perhaps cannot be stable or permanently separated. This is part of the theory of quark confinement, which explains how quarks can exist and yet never be isolated or directly observed. Finally, an extra quantum number with three values (like those we assign to color) is necessary for quarks to obey the Pauli exclusion principle. Particles such as the , which is ++ composed of three strange quarks, sss , and the , which is three up quarks, uuu, can exist because the quarks have different colors and do not have the same quantum numbers. Color is consistent with all observations and is now widely accepted. Quark theory including color is called quantum chromodynamics (QCD), also named by Gell-Mann. Q: Quantum chromodynamics combines what property with quark theory? Choices: - mass - contrast - sound - color A:
(A).
color
Ques:Answer the following question given this paragraph: Continental crust is much thicker than oceanic crust. It is 35 kilometers (22 miles) thick on average, but it varies a lot. Continental crust is made up of many different rocks. All three major rock types igneous, metamorphic, and sedimentary are found in the crust. On average, continental crust is much less dense (2.7 g/cm3) than oceanic crust. Since it is less dense, it rises higher above the mantle than oceanic crust. Q: How thick is the earth's continental crust, on average? Choices: - 60 kilometers - 15 kilometers - 25 kilometers - 35 kilometers A:

Ans:35 kilometers
Ques: Answer the following question given this paragraph: The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. Q: What tube carries urine out of the body? Choices: - fallopian tube - uterus - kidney - urethra A:
Ans:
urethra