Answer the following question given this paragraph: The cell is the smallest unit of structure and function of all living organisms. A cell is also the smallest unit of life, with single-celled organisms present on this planet for over 3.5 billion years. Single-celled ( unicellular ) organisms like bacteria are obviously composed of just one cell, whereas multicellular organisms can be composed of trillions of cells. Multicellular organisms include protists (though single-celled protists also exist), fungi, plants and animals. Most plant and animal cells are between 1 and 100 m and therefore can only be observed under the microscope. Q: What is the smallest unit of structure and function of all living organisms? Choices: - chromosome - organelle - organ - the cell A:
the cell
Answer the following question given this paragraph: Chemical symbols are useful to concisely represent the elements present in a substance. The letters usually come from the name of the element. Q: Chemical symbols are useful to concisely represent the elements present in a substance. the letters usually come from the name of what? Choices: - month - scientist - discoverer - element A:
element
Q: Answer the following question given this paragraph: The new cells gradually move up through the epidermis toward the surface of the body. As they move, they produce the tough, fibrous protein called keratin. Q: What is the most common cause of lung cancer? Choices: - coal smoke exposure - restaurant smoke exposure - tree smoke exposure - tobacco smoke exposure A:
A: tobacco smoke exposure
Question: Answer the following question given this paragraph: ♦️ Many industrial processes for preparing compounds use "continuous-flow reactors," which are chemical reaction vessels in which the reactants are mixed and allowed to react as they flow along a tube. The products are removed at a certain distance from the starting point, when the reaction is nearly complete. The key operating parameters in a continuous-flow reactor are temperature, reactor volume, and reactant flow rate. As an industrial chemist, you think you have successfully modified a particular process to produce a higher product yield by substituting one reactant for another. The viscosity of the new reactant is, however, greater than that of the initial reactant. Q: Continuous-flow reactors are chemical reaction vessels in which the what are mixed and allowed to react as they flow along a tube? Choices: - reactives - generators - propellants - reactants A:
Answer: reactants
*Question*
Answer the following question given this paragraph: Isotopes of Hydrogen Hydrogen, the most abundant element in the universe, is the ultimate source of all other elements by the process of nuclear fusion. (For more information on nuclear fusion, seeChapter 20 "Nuclear Chemistry". ) Table 21.2 "The Isotopes of Hydrogen" compares the three isotopes of hydrogen, all of which contain one proton and one electron per atom. The most common isotope is protium (1H or H), followed by deuterium (2H or D), which has an additional neutron. The rarest isotope of hydrogen is tritium (3H or T), which is produced in the upper atmosphere by a nuclear reaction when cosmic rays strike nitrogen and other atoms; it is then washed into the oceans by rainfall. Tritium is radioactive, decaying to 3He with a half-life of only 12.32 years. Consequently, the atmosphere and oceans contain only a very low, steadystate level of tritium. The termhydrogen and the symbol H normally refer to the naturally occurring mixture of the three isotopes. Table 21.2 The Isotopes of Hydrogen. Q: What is the most abundant element in the universe? Choices: - carbon - helium - nitrogen - hydrogen A:
**Answer**
hydrogen
(Question)
Answer the following question given this paragraph: At the end of the Cretaceous Period, or 65 million years ago, all dinosaurs (except those which led to birds) went extinct. Some scientists believe a possible cause is a collision between the Earth and a comet or asteroid. The collision could have caused tidal waves, changed the climate, and reduced sunlight by 10-20%. A decrease in photosynthesis would have resulted in less plant food, leading to the extinction of the dinosaurs. Q: A comet striking the earth may have caused mass extinction, this would have decreased sunlight, which would have effected what plant process reducing food? Choices: - fertilization - decomposition - glycolysis - photosynthesis A:
(Answer)
photosynthesis