Introduction to Life Science BSC 1005 Fall 2011 Homework 1 Connect Due Date: 9/18/2011 11:59PM Instructions Complete this homework assignment as the material is covered in class. You may refer to any of the course resources including the text, lecture notes, and Connect. In order to receive credit for this homework assignment you must enter and submit your final answers online through Connect before the due date. Multiple Choice Portion 1.Science is a. an organized study of information. b. impossible to define. c. a process for collecting and organizing knowledge. d. the study of life. 2.A hypothesis is best described as a. a general principle. b. a logical explanation that can be tested. c. a theory. d. a generally accepted concept. 1
3.An experimental group a. is the same as the control group. b. differs from the control group by one variable. c. differs from the control group by several variables. d. is not necessary if an experiment contains a control group. 4.If one group is given some medicine that may cure a disease and the other group is given a sugar pill, the group who got the medicine is the a. Hypothetical group. b. Scientific group. c. Control group. d. Experimental group. 5.A control group differs from an experimental group a. in the number of test organisms used. b. by the independent variable. c. by the dependent variable. d. in no way. 6.In an experiment that has a control and experimental group, the dependent variable is a. observed in the experimental group. b. not observed in the control group. c. the result of the independent variable. d. All of these statements are true. 7.If you want to set up a controlled experiment to determine the effects of caffeine on sleeping behavior in mice, you take a group of mice and divide it into two groups. Both are fed the same food, both are watered, both have 12 hours daylight, and 12 hours dark. Group one is given caffeine. What is appropriate to give to group two? a. 2 amount of caffeine b. 1/2 amount of caffeine c. No caffeine d. Caffeine in different form 2
8.Controls are necessary in scientific experiments because they a. serve as a basis for comparison with the experimental results. b. enable the investigator to control the results. c. always confirm your observation. d. allow the investigator to develop experience in science. 9.A good experimental design should a. be designed to prove a hypothesis is correct. b. be able to be repeated. c. not have an independent variable. d. All of these statements are true. 10."All adult women in the experiment responded favorably to the medication. However, young girls did not." In this situation a. age was the dependent variable. b. the way adult women responded was the dependent variable. c. age was the independent variable. d. girls were the dependent variable. 11.Which of the following has the LEAST general acceptance? a. Theory. b. Law. c. Hypothesis. d. Theory, law, and hypothesis have equal acceptance. 12.Which sequence correctly lists levels of organization from simple to more complex? a. Biosphere, ecosystem, community, population b. Atoms, cell, molecules, tissue, organism c. Organ system, organ, organisms, cell d. Cell, tissue, organ, organ system 3
13.Which term BEST describes populations of trees, insects, mammals, fungi, bacteria, and many other organisms that interact in any location? a. biosphere b. ecosystem c. bioregion d. community 14.The process of maintaining a constant internal environment is called a. homeostasis. b. metabolism. c. induction. d. deduction. 15.All of the chemical reactions that take place within your body are known as a. organismal structure. b. metabolism. c. irritability. d. adaptation. 16. are the fundamental structural units of all living things. a. Molecules b. Atoms c. Cells d. Protons 17.Populations of different kinds of organisms that interact with one another in a particular place are known as a. ecosystems. b. communities. c. a biosphere. d. a commune. 4
18.Evolution is the a. slow change in the genetic makeup of a population of organisms over many generations. b. fast change in the genetic makeup of a population of organisms over many generations. c. slow change in the genetic makeup of an individual over a lifetime. d. fast change in the genetic makeup of an individual over a lifetime. 19.An atom that has gained electrons is a a. reactant. b. negative ion. c. positive ion. d. compound ion. 20.A carbon atom that has gained a proton is a. an ion b. an anion c. a nitrogen ion d. a cation 21.An atom with twelve electrons, twelve protons, and fourteen neutrons has a mass number of a. fourteen. b. twenty-four. c. thirty-eight. d. twenty-six. 22.A hydroxide ion has an oxygen atom a. only. b. and an extra electron. c. and a hydrogen atom, and an extra electron. d. and a hydrogen atom, and an extra proton. 5
23.Solutions are always comprised of a. solvents and solute. b. liquids and solids. c. water and salts. d. compounds and ions. 24.A covalent bond is a. the attraction that one atom has for another atom. b. the attraction between two atoms, formed by the sharing of electrons. c. formed between the positive charge of a hydrogen atom in one molecule and the negative charge of a nitrogen atom in another nearby molecule. d. the attraction between a positive ion and a negative ion. 25.An acid is a substance that, in solution, releases a. oxygen ions in H2SO4. b. hydrogen ions, for example, HCl. c. COOR ions from beer. d. chloride ions from NaCl. 26.A base can be defined as a. a hydroxide ion acceptor. b. an attraction between a positive ion and a negative ion. c. a substance that gives up hydrogen ions when dissolved in water. d. a substance that gives up hydroxide groups in a solution. 27.An isotope is an atom of an element that varies in mass number due to variation in the number of a. atoms. b. protons. c. neutrons. d. electrons. 6
28.A solution that contains an excess of protons is(are) a. hydroxide ions. b. an acid. c. a base. d. the ph. 29.An isotope shows which of the following? a. A change in atomic number b. Inability to form compounds c. A change in mass number d. More electrons 30.Which of the following is a chemical reaction that is also known as digestion? a. phosphorylation b. dehydration synthesis c. acid-base d. hydrolysis 31.Which kind of chemical reaction involves the attachment or removal of a phosphate group? a. oxidation-reduction b. acid phosphorylation c. phosphorylation d. hydrolysis 32.Which of the following is an acid? a. K2SO4 b. NaNO3 c. CaCO3 d. H3PO4 7
33.6CO2 + 6H2O C6H12O2 + 6O2. In this reaction O2 is a. a reactant. b. a product. c. a reactant and a product. d. neither a reactant nor a product. 34.Which kind of attractive force holds two molecules together? a. ionic bond b. hydrogen bond c. covalent bond d. sticky bond 35.A solution with a high concentration of hydrogen ions could have a ph of a. 2 b. 6 c. 9 d. 11 36.The attraction between a positively charged atom and a negatively charged atom within the same molecule is a. ionic bonding. b. hydrogen bonding. c. covalent bonding. d. ions. 37.The reaction C6H12O6 + O2 CO2 + 6H2O is which type of chemical reaction? a. hydrolysis b. transfer c. dehydration synthesis d. oxidation-reduction 8
38.HCl + NaOH NaCl + H2O. This reaction is an example of a(n) a. oxidation/reduction reaction. b. hydrolysis reaction. c. phosphorylation reaction. d. acid-base reaction. 39.The atomic number for carbon is 6. The isotope 14 C has neutrons. a. 6 b. 8 c. 14 d. 20 40.A neutral atom with an atomic number of 15 will have electrons in its outermost energy level. a. 3 b. 5 c. 8 d. 15 41.The higher the ph, a. the greater the hydroxide ion concentration. b. the more acidic the solution. c. the greater the hydrogen ion concentration. d. the lower the ph number. 42.A magnesium ion contains twelve protons and ten electrons. A chloride ion contains seventeen protons and eighteen electrons. Given this information, the chemical formula for magnesium chloride is a. MgCl. b. Mg2Cl. c. MgCl2. d. Mg2Cl2. 9
43.Which combination of elements is most likely to form an ionic bond based on their positions in the Periodic Table of the Elements? a. Na and Cl b. Na and Mg c. F and Ne d. All would react. 44.When you add a salt such as NaCl to an aqueous solution, the salt a. ionizes. b. dissociates. c. forms covalent bonds with the food. d. undergoes an acid-base reaction. 45.Which of the following is a base or alkaline material? a. NaOH b. HCl c. H2SO4 d. NaCl 46.Which of the following is a salt? a. NaOH b. HOH c. H2SO4 d. MgCl2 47.Why is the following reaction considered to be dehydration synthesis? H-NH3C2O-OH + H-NH3C2O-OH H-NH3C2O- NH3C2O-OH + H-OH a. Water molecules are hidden in the products H-NH3C2O-NH3C2O-OH. b. This is the same reaction that occurs during digestion and water is required. c. Water molecules are formed as a result of the breakdown of H-NH3C2O- NH3C2O-OH. d. Water molecules are formed as a new, more complex end product is formed. 10
48.When electrons in a covalent bond are not equally shared, the molecule is said to be a. polar. b. nonpolar. c. lopsided. d. unable to form hydrogen bonds. 49.These are mixtures of weak acids and the salts of weak acids that tend to maintain constant ph. a. buffers b. oxidants c. electrolytes d. soft drinks 50.Saturated fats differ from unsaturated fats in that saturated fats a. are longer. b. lack carbon-carbon double bonds. c. have fewer double bonds. d. cannot be used for an energy source. 51.A subunit of protein is a(n) a. amino acid. b. nucleic acid. c. fatty acid. d. phospholipid. 52.Which of the following types of molecules contain the most energy per gram? a. sugar b. carbohydrate c. saturated fat d. starch 11
53.CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-COOH is a(n) a. fatty acid. b. amino acid. c. glycerol. d. steroid. 54.Storage of energy is a MAJOR function of a. protein. b. fats. c. steroids. d. nucleic acids. 55.Triglycerides contain three fatty acids and a. one glycerol. b. two glycerols. c. three glycerols. d. four glycerols. 56.An example of an inorganic molecule is a. C6H12O6. b. HCl. c. C4H8O4. d. C12H22O11. 57.An example of a carbohydrate is a. C7H14O7. b. C7H12O7. c. C7H14O28. d. C7H7O7. 12
58.This is a(n) reaction. C12H22O11 + H2O C6H12O6 + C6H12O6 a. hydrolysis b. dehydration synthesis c. acid-base d. ionic 59.Molecules that resemble fats but contain phosphate functional groups are called a. steroids. b. polypeptides. c. phospholipids. d. nucleic acid. 60.Carbohydrates are a source of a. protein. b. energy. c. glycerol. d. fatty acids. 61.A protein a. is a macromolecule. b. consists of many linked amino acids. c. may be made of two or more polypeptides. d. is correctly described by all three of these answers. 62.glycerol + 3 fatty acids triglyceride + 3 H2O This is a(n) reaction. a. hydrolysis b. dehydration synthesis c. unbalanced d. acid-base 13
63.Which of the following shows the correct linkage of amino acids in a protein? a. amino group of one bonded to the amino group of the next b. acid group of one bonded to acid group of the next c. acid group of one bonded to amino group of the next d. All of these answers are correct. 64.Which is NOT a major function of proteins? a. Provides cell structure. b. Stores energy for the cell. c. Functions as regulator molecules in cellular activity. d. Functions as carrier molecules. 65.The molecule below is a(n) a. glycerol. b. polypeptide. c. saturated fatty acid. d. unsaturated fatty acid. 66.The molecule below is a(n) a. amino acid. b. carbohydrate. c. lipid. d. nucleic acid. 67. is a sugar. a. Sucrase b. Pentose c. C27H46O d. COOH-CH2-NH3 14
68.The pleating or coiling of a protein is known as the protein's structure. a. primary b. secondary c. tertiary d. quaternary 69.Which of the following statements is FALSE concerning the bonding of amino acids? a. The bond formed between two amino acids is called a peptide bond. b. When two amino acids combine, the amino group of one molecule will combine with the acid group of the second molecule. c. The addition of one water molecule is required to combine two amino acids. d. A series of amino acids bonded together is a polypeptide. 70.Which of the following rows correctly matches organic molecules with their subunits? a. Row 1 b. Row 2 c. Row 3 d. Row 4 71.The bonding of four simple sugars will a. produce three water molecules. b. produce four water molecules. c. utilize three water molecules. d. utilize four water molecules. 72. contains double bonds. a. CH4 b. H2O c. CO2 d. NH3 15
73.A nucleotide contains a. glycerol and fatty acids. b. a base, sugar, and phosphate group. c. amino acids. d. an acid, base, and salt. 74.A lipid molecule composed of interlocking carbon rings belongs most likely in which group? a. phospholipid b. steroid c. unsaturated fat d. glycerol 75.Molecules with the same empirical formula but different structural formulas are a. polymers. b. steroids. c. isomers. d. enzymes. 76.Which one of the following is a correct molecular formula? a. b. c. d. 16
77.Which components must be removed during a dehydration synthesis reaction? a. -H and -OH b. -N= and -OH c. -OH and COOH d. COOH and -H 78.When four polypeptides are joined together by covalent bonds, they form a new, biologically active molecule that displays structure. a. primary b. secondary c. tertiary d. quaternary 79.In a nucleotide, the nitrogenous base is bonded to a. an acid. b. a sugar. c. a phosphate. d. itself. 80.Which of the following best describes the structure of DNA? a. single helix b. protein coil c. double helix d. globular RNA 81.The backbone of a double helix is a. sugar-phosphate. b. hydrogen bonds. c. base-pairing. d. All of these answers are true. 17
82.Fats are a. polar molecules. b. nonpolar molecules. c. hydrophilic. d. amphiphilic. 18