HW Problem Set 1 Chpts 1 6 Spring 2015 1 Which of the following is are good example s of an hypothesis A Living organisms evolve by natural selection B Students in Bio 118 who engage more with the subject matter do better on exams C All organisms are made from cells and all cells come from preexisting cells D A rock is made of cells E B D 2 Which part of the cell theory is NOT supported by the appearance of the first living cells A The pattern component of the cell theory All organisms are made of cells B The pattern component of the cell theory All cells come from pre existing cells C The process component of the cell theory All organisms are made of cells D The process component of the cell theory All cells come from pre existing cells E None of the above select E if none of the above are correct 3 In Louis Pasteur s famous experiment to test whether cells arise spontaneously from non living materials or whether cells come from other cells he used straight necked flasks versus swan necked flasks see Figure below Which of the following statements about this experiment is INACCURATE A The results of this famous experiment provide crucial evidence in support of the Cell Theory B In terms of the experimental design the single most important reason to have flasks open to the air and not stoppered is to allow water vapor to escape while boiling C No cell growth in the swan necked flasks REJECTS the spontaneous generation hypothesis because otherwise cells were expected to grow D No cell growth in the swan necked flask SUPPORTS the cells come from other cells hypothesis because the trap that was created by the swanshaped neck resulted in no cells getting into the broth E None of the above This means select Answer E if all four answers A D are ACCURATE about this experiment and none are INACCURATE 4 What is the fundamental difference between covalent and ionic bonding A In a covalent bond the atoms have identical electronegativity in an ionic bond one of them is more electronegative B Covalent bonding involves only the outermost electron shell ionic bonding also involves the next electron shell inside the outermost shell C In covalent bonding both atoms end up with filled outer electron shells in ionic bonding one atom does and the other does not D In a covalent bond the atoms share a pair of electrons in an ionic bond one atom accepts electrons from the other E Covalent bonds form between atoms of the same element ionic bonds form between atoms of different elements 5 Most polar covalent bonds involve nitrogen or oxygen because A nitrogen and oxygen are highly electronegative and they repel electrons B nitrogen and oxygen have low electronegativity and they attract electrons C nitrogen and oxygen have low electronegativity and they repel electrons D nitrogen and oxygen are highly electronegative and they attract electrons E None of the above This means select E if none of the above accurately complete the sentence 6 Which of the following statements is are TRUE about the bond developed between atoms that form bonds with themselves such as hydrogen gas H2 or Oxygen gas O2 A electronegativity of the two atoms within such molecules are identical hence sharing of electrons is equal This results in the formation of a nonpolar covalent bond B electronegativity of the two atoms within such molecules are identical hence sharing of electrons is equal This results in the formation of a polar covalent bond C electronegativity of the two atoms within such molecules are different hence sharing of electrons is unequal This results in the formation of a nonpolar covalent bond D electronegativity of the two atoms within such molecules are different hence sharing of electrons is unequal This could result in the formation of a polar covalent bond E B D This means select E if both answers B and D are TRUE 7 Which of the following statements about the chemical structure of water is TRUE A Water is a polar molecule because of its hydrogen bonds B The partial positive charge of water s oxygen atom results in the bent form of the water molecule and is involved in the formation of hydrogen bonds between adjacent water molecules C Because of its polarity water passes easily through lipid plasma membranes D Because hydrogen is less electronegative than oxygen electrons spend less time near the hydrogen resulting in a polar covalent bond forming between the hydrogen and oxygen atoms 1 E All of the above This means select answer E if all of the above are TRUE 8 When electrons are shared equally between atoms they form A a polar covalent bond B a non polar covalent bond C an ionic bond D a hydrogen bond E van der Waals forces 9 How do R groups of amino acids differ from one another A size B shape C polarity D reactivity E All of the above This means select E if all of the above are ways in which they might differ 10 Which of the following is true of carbon A It forms only polar bonds B It forms only non polar bonds C It can form both polar and non polar bonds D It is highly electronegative E It can from a maximum of 3 covalent bonds with other elements 11 When considering whether an amino acid falls into one of the three major groups non polar polar or electrically charged which of the following is accurate A You must look at the amino group B You must look at the carboxyl group C You must look at the side chains D You must look at the carbon backbone E All of the above This means select E if all of the above are correct 12 Based on the molecular formulas provided below and your knowledge of function groups see figure place the following molecules in descending order starting with that which has the largest number of polar covalent bonds to that having the least number of polar covalent bonds 1 acetic acid C2H4O2 carboxyl functional group 2 amino acid glycine C2H5NO2 amino and carboxyl functional groups 3 glycerol C3H8O3 hydroxyl functional group 4 acetaldehyde C2H4O carbonyl functional group 5 ethanol C2H6O hydroxyl functional group A B C D E Some functional groups 3 2 5 4 1 2 3 1 5 4 3 1 2 4 5 3 2 1 5 4 2 3 5 1 4 13 Which of the following molecules would you predict to have the largest number of polar covalent bonds based on their molecular formulas A C2H4O acetaldehyde B C2H5NO2 glycine C C2H6O ethanol D C2H4O2 acetic acid E none of the above have polar covalent bonds 2 Refer to the accompanying figure to answer the following question 14 At which bond would water need to be added to achieve hydrolysis of the