Human Biology Chapter 02 Chemistry of Life – Flashcards
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The smallest unit of an element that still retains the chemical and physical properties of that element is called A. an isotope. B. a nucleus. C. an atom. D. a molecular bond. E. a neutrino.
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C
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In an atom, the number of protons always equals the number A. of electrons. B. of neutrons. C. of neutron and protons. D. of quarks. E. of neutrinos.
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A
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Examine the section of the periodic table in Figure 2.1. Which element will behave similarly to C? A. Ca B. S C. Ar D. Si E. Mg
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D
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How many elements occur naturally? A. 112 B. 92 C. 64 D. 32 E. 6
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B
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The atomic number of an atom is determined by the number of A. protons. B. neutrons. C. electrons. D. protons and neutrons. E. protons and electrons.
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A
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True or False: An element cannot be broken down by chemical means.
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True
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Why is He over Ne in the periodic table? (Refer to Figure 2.1) A. They both have the same atomic mass. B. They both have the same number of electrons in their outermost orbital. C. They both have a full outermost orbital. D. They both have the same atomic number. E. They both have the same number of protons in their nuclei.
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C
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Be has an atomic number of 4 and an atomic mass of 9. How many protons does it have? A. 4 B. 5 C. 9 D. 13
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A
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What is the symbol for sodium? A. Na B. S C. So D. N E. Dm
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A
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An element has its outermost orbital full and contains more than 2 electrons. Which element is this? A. He B. Ne C. C D. N E. O
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B
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Isotopes of an element differ due to the number of A. protons. B. neutrons. C. electrons. D. both protons and electrons. E. neutrinos.
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B
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Carbon dating is a common method employed in dating certain kinds of fossils. It is based upon the radioactive decay of an isotope of carbon (C14). Referring to the atomic number of carbon attained from figure 2.1, how many neutrons does C14 have? A. 2 B. 4 C. 8 D. 12 E. 14
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C
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What is iodine 131, used in medicine to produce various images of organs and tissues, called? A. A mixture B. A tracer C. An emulsion D. A colloid E. A sensor
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B
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True or False: Radiation can produce both positive and negative effects for humans.
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True
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A combination of two or more atoms of the same type is called A. an atomic unit. B. a molecule. C. a compound. D. an isotope. E. an ion.
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B
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Ca3(PO4)2 represents a/an A. element. B. mixture. C. compound. D. isotope. E. atom.
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C
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Atoms that share electrons have what type of bonds? A. covalent B. neutral C. hydrogen D. colloidal E. ionic
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A
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CaCl2 is a salt that forms as the result of what type of bond? A. covalent B. hydrogen C. polar D. non-polar E. ionic
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E
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True or False: Water makes up 60-70% of total body weight.
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True
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Hydrogen bonds A. result from the loss of neutrons by an atom. B. result in the formation of salts. C. involve the loss and gain of electrons. D. involve the sharing of electrons. E. are relatively weak and can be broken rather easily.
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E
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The reason water is polar is because A. in polar molecules atoms share electrons evenly. B. the oxygen atom is larger than the hydrogen atom. C. hydrophilic molecules interact with water. D. hydrophobic molecules do not interact with water. E. there is a transfer of electrons from the hydrogen to the oxygen.
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B
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Which of the following characteristics of water is most responsible for the sinking of the Titanic? A. Water is liquid at room temperature. B. Water has a high heat of vaporization. C. The temperature of liquid water rises and falls slowly. D. Frozen water is less dense than liquid water. E. Water molecules are cohesive.
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D
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On a warm day in April, Tina jumped into the swimming pool. To her surprise the water was really cold. Which property of water did she discover? A. Water molecules are cohesive. B. The temperature of liquid water rises and falls slowly. C. Water possesses hydrogen bonds. D. Water is a polar molecule. E. Frozen water is less dense than liquid water.
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B
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William noticed blood mysteriously climbing up a capillary tube. This is an example of which property of water? A. Frozen water is less dense than liquid water. B. The temperature of liquid water rises and falls slowly. C. Water molecules are cohesive. D. Water has a high heat of vaporization. E. Water is a solvent.
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C
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In an acidic solution A. the number of H+ is less than the number of OH-. B. the number of H+ is greater than the number of OH-. C. the number of H+ is equal to the number of OH-.
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B
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True or False: A solution with a pH of 7 has 10 times as many H+ as a pH of 6.
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False
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A solution containing 0.00001 moles of H+ has a pH of A. 3 B. 5 C. 7 D. 9 E. 11
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B
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True or False: The presence of a buffer in our blood is an example of homeostasis.
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True
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Joining small molecules (monomers) together to form longer chains (polymers) requires a process called A. a hydrolysis reaction. B. a dehydration reaction. C. monomerization. D. emulsification. E. disassembly.
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B
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Which of the following is not one of the four classes of organic molecules found in cells? A. vitamins B. lipids C. proteins D. carbohydrates E. nucleic acids
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A
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True or False: NaCl is not an organic molecule.
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True
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True or False: A hydrolysis reaction involves the loss of water.
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False
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Sugars with three to seven carbon atoms are called A. monosaccharides. B. disaccharides. C. trisaccharides. D. polysaccharides. E. steroids.
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A
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Which of the following is not a monosaccharide? A. glucose B. fructose C. galactose D. maltose
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D
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What passes through the digestive tract as fiber or roughage? A. Chitin B. Glucose C. Glycogen D. Starch E. Cellulose
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E
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Which polysaccharide is branched the most? A. cellulose B. starch C. glycogen
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C
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True or False: The main function of carbohydrates is for long-term energy storage.
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False
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True or False: Our body is capable of converting starch into glycogen.
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True
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Starch, cellulose, and glycogen are alike in that A. they are all made of glucose. B. they contain the same number of side chains. C. they have the same types of bonds between the monomer units. D. they are all found in animals. E. they can all be digested by our bodies.
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A
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A fat contains how many fatty acids? A. 1 B. 2 C. 3 D. 4 E. 5
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C
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How are fats, phospholipids, and steroids alike? A. They are all solid at room temperature. B. They each contain a polar phosphate group. C. They each contain only 1 fatty acid. D. They do not dissolve in water. E. They all contain at least one carbon ring.
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D
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A fatty acid that contains only single bonds between the carbon atoms is considered A. saturated. B. unsaturated. C. trans unsaturated.
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A
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True or False: Fats are usually of animal origin while oils are usually of plant origin.
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True
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The sex hormones belong to which category of lipids? A. steroids B. fats C. oils D. triglycerides E. phospholipids
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A
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The membranes of cells are composed of A. phospholipids. B. fats. C. oils. D. steroids. E. triglycerides.
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A
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True or False: Fats and oils function well as energy-storage molecules because they contain carbon.
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False
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The monomer unit of a protein is A. fatty acids. B. amino acids. C. monosaccharides. D. polysaccharides. E. nucleic acids.
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B
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What makes each amino acid unique? A. the central carbon B. the R group C. the amino group D. the carboxyl group
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B
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Which of the following is not a function of proteins? A. quick energy B. support C. transport D. enzymes E. motion
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A
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An alpha helix or a beta sheet are examples of what level of protein structure? A. secondary B. primary C. tertiary D. quaternary
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A
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When two amino acids combine via a dehydration reaction, A. a peptide bond is formed. B. the R groups are lost. C. water is added to begin the reaction. D. the carboxyl group of each join together. E. the amino group of each join together.
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A
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True or False: All amino acids are alike in that their R groups are polar.
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False
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The sides of the DNA ladder (backbone) are A. alternating carbons and nitrogens. B. the R groups. C. the nitrogenous bases. D. alternating nitrogens and phosphates. E. sugars and phosphates.
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E
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When an ATP molecule is used to supply energy, which of the following occurs? A. a phosphate bond is added B. a phosphate bond is broken C. oxygen is removed D. oxygen is added E. an adenine is added
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B
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Which of the following nitrogenous bases is NOT found in DNA? A. cytosine B. thymine C. uracil D. guanine E. adenine
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C
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Which of the following is not present in a nucleotide? A. phosphate B. nitrogenous base C. 5 ring sugar D. an R group E. a pentose
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D
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A species has 29% of its DNA composed of the nucleotide containing guanine (G). What percent does the nitrogen base thymine (T) equal? A. 58% B. 42% C. 21% D. 67% E. 29%
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C
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ATP carries energy in the form of high-energy A. carbohydrate bonds. B. peptide bonds. C. lipid bonds. D. phosphate bonds. E. hydrogen bonds
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D
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True or False: The function of RNA in the body is to store the genetic information in the nucleus.
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False
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True or False: ATP is called the energy currency of the body because it is a type of electricity
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False
