This has been the 2162nd visit to this site since September 2, 1996.

GENERAL INSTRUCTIONS:
1. Print name, section number, and student ID number in the ID portion of your machine-graded answer sheet and fill in the corresponding circles.
2. Use a #2 pencil to mark the answer sheet.
3. Mark only ONE answer per question.
4. Return the answer sheet and the question sheet.

1. An electrically neutral atom has as many protons as
A) neutrons
B) valence electrons
C) electrons
D) none of these

2. Acetone (C3H6O) is
A) an aldehyde
B) a hydrocarbon
C) an alcohol
D) a ketone
E) none of these

3. Nucleotides are composite molecules consisting of
A) hexoses, phosphates, and glycerol
B) nitrogenous bases, phosphates, and amino acids
C) fatty acids, phosphates, and a nitrogenous bases
D) pentoses, phosphates, and nitrogenous bases

4. Tritium is an isotope of hydrogen. Which of the following is true?
A) Tritium can form one more covalent bond than hydrogen.
B) Tritium and hydrogen have the same atomic number.
C) Tritium and hydrogen have the same number of neutrons.
D) Both B and C.

5. Nucleotides, amino acids and simple sugars are the respective monomers for which of the following polymers?
A) proteins, DNA, and polysaccharides
B) DNA, proteins, and polysaccharides
C) polysaccharides, proteins, and DNA
D) none of these

6. Polar molecules are likely to be
A) hydrocarbons
B) hydrophilic
C) hydrophobiC
D) A and B

7. A carbon atom can form ________ bonds with four hydrogen (H) atoms.
A) 4 covalent
B) 4 ionic
C) 4 hydrogen
D) all of these

8. Stromatolites
A) are composed of eukaryotic cells
B) are the oldest known fossils, being found in 5 billion year-old rocks
C) cover the ocean floor near hydrothermal vents
D) no longer occur on the earth
E) none of these

9. The original Miller-Urey experiments showed that
A) life can be created in a test tube
B) nucleic acids were present in the early atmosphere
C) amino acids could have formed in the early atmosphere
D) aliens from outer space once visited the earth
E) none of these

10. The arrangement of hydrogen atoms around the carbon atom in methane can be best approximated by a
A) square
B) box
C) circle
D) tetrahedron
E) quadrahedron

11. Most unicellular eukaryotes are placed in the kingdom
A) Monera
B) Animalia
C) Protoctista (Protista)
D) Plantae
E) none of these

12. Water beads on wax because....
A) wax is very hydrophobic.
B) water molecules adhere very strongely to wax molecules.
C) water is very cohesive due to hydrogen bonds.
D) A an C

13. A chain of glucose molecules linked together by alpha-1,4-glycosidic linkages could be called...
A) a storage polysaccharide
B) amylose
C) a starch
D) all of these

14. Unlike the atmosphere today, the primordial atmosphere
A) contained carbon dioxide
B) filtered out less ultraviolet radiation
C) had more oxygen
D) none of these

15. What are the most common elements in living organisms?
A) C, N, and K
B) C, P, and K
C) C, O, and H
D) C, S, and Ca

16. Which of the following is true of a double strand of DNA?
A) T forms hydrogen bonds with U
B) A forms covalent bonds with T
C) G forms hydrogen bonds with C
D) G forms ionic bonds with C

17. An atom of deuterium has one proton, one neutron, and an atomic mass of
A) 1
B) 3
C) 2
D) 4
E) None of these

18. Amino acids always contain which of the following functional groups?
A) amino
B) sulfhydryl
D) A and B
C) carbonyl
E) all of these

19. Ionic bonds require the.......
A) sharing of electrons.
B) lose of neutrons.
C) transfer of electrons.
D) A and C

20. An example of the secondary structure of a protein is.....
A) a polypeptide chain
B) a BETA-pleated sheet
C) a chain of nucleotides
D) an enzyme containing 2 subunits

21. Sidney Fox did the "drying puddle" experiments to demonstrate
A) that nucleic acids existed in the early atmosphere
B) that life evolved on land
C) how polypeptides may have been formed

22. A glass of water from the tap has a pH of 6. What is the concentration of
hydrogen ions (H+) in that water?
A) 10^6 M
B) 10^8 M
C) 10^-8 M
D) 10^-6 M
E) none of these

23. If an animal contains 1000 atoms of 14C when it dies, how many atoms of 14C will it contain 11,200 years after it dies? (half-life of 14C is 5600 years)
A) 4000
B) 500
C) 125
D) 2000
E) 250

24. A carbon atom is most stable when its outer energy level contains
A) 8 electrons
B) 4 protons
C) 6 electrons
D) 14 neutrinos
E) 8 neutrons

25. Monosaccharides such as fructose and glucose are isomers of one another and contain which functional groups?
A) amino and hydroxide
B) phosphate and carbonyl
C) carbonyl and hydroxide
D) hydroxide and carboxyl

26. A single water molecule is held together by _______ bonds.
A) nonpolar ionic
B) polar covalent
C) nonpolar covalent
D) polar ionic

27. Theories are
A) indisputable facts.
B) written in stone.
C) subject to change if new facts are discovered.
D) hypotheses that have been disproven.

28. A carboxyl group has acidic behavior because
A) it releases hydroxide ions
B) carbon can form 4 covalent bonds
C) oxygen is more electronegative than hydrogen

29. The first (lowest) energy level of an atom has one orbital and can contain a maximum of....
A) 1 electron
B) 4 electrons
C) 2 electrons
D) 8 electrons

30. Two fatty acids have chain lengths of 16 carbon atoms. One is saturated and one is unsaturated. Which has more double bonds?
A) the saturated fatty acid
B) the unsaturated fatty acid
C) neither of these

31. Monomers such as monosaccharides are bonded together to form polymers by
A) hydrolytic reactions
B) dehydration reactions
C) hydrophobic interactions
D) denaturation reactions

32. Which hydrocarbon has a double bond in its carbon skeleton?
A) C4H10
B) C2H6
C) C3H8
D) C3H6
E) none of these

33. Which functional groups are important in the formation and function of phospholipids?
A) phosphate and carbonyl
B) hydroxide and phosphate
C) phosphate and carboxyl
D) hydroxide and amino

34. Cows are able to thrive on a diet of grass because they
A) grow very slowly
B) have amylases in their rumens
C) contain microorganisms that can digest hexoses
D) do not need protein
E) none of these

35. Hydrogen bonds are _________ than covalent bonds.
A) stronger
B) weaker
C) more stable than
D) A and C
E) none of these

36. When sodium chloride dissolves in water, which of the following are released?
A) sodium cations
B) sodium anions
C) Cl+
D) all of these

37. Which of the following are structural polysaccharides?
A) starch
B) glycogen
C) cellulose
D) all of these
E) amylose

38. The binomial system of naming organisms was first used by
A) Oparin
B) Plato
C) Linnaeus
D) Darwin
E) none of these

39. Methane (CH4) is a very __________ molecule.
A) polar
B) oxidized
C) assymetrical
D) none of these

40. An individual water molecule has a partial positive charge
A) at the oxygen end of the molecule
B) in the middle of the molecule
C) due to a hydroxide functional group
D) near the two hydrogen atoms