Name: _____________________ Bioscience 140 Midterm SSN/ID:   _____________________




Directions: This exam is open book, open calculator, and closed notes. All questions are worth 5 points each so if you get stuck on a problem, move on and come back to it later. Although there are 21 questions in all, you only need to answer 20 of them. Any extra questions you answer will be counted as extra-credit if you get them right (up to a maximum score of 100). You will be allowed the entire two hours to finish this exam so take your time. Just settle back into your chair, take a deep breath, and relax... Best of luck!



  1. Actinosphenia elegans is a unicellular, photosynthetic, eukaryotic organism. To which domain does it belong?
    Answer:
    C. Eukarya (Eukaryotes)
    See Ch. 1
    1. Bacteria (Eubacteria)
    2. Archaea (Archaebacteria)
    3. Eukarya (Eukaryotes)
    4. Plantae
    5. none of the above





  2. T/F: A theory is a well-supported concept that has broad explanatory power.
    Answer:
    True.
    See Ch. 1





  3. Natural selection requires a ________________ variation and ___________________ reproductive success. Please describe what this means in your own words.
    Answer:
    heritable, differential
    See Ch. 1





  4. Science itself is NOT capable of:
    Answer:
    D. addressing questions of ethical dilemmas
    See Ch. 1
    1. determining the physical causes for physical phenomena
    2. formulating testable hypotheses
    3. explaining naturally occurring events
    4. addressing questions of ethical dilemmas
    5. determining the efficacy of a diet





  5. Discovery science is based on ______________ reasoning whereas experimental science is based on _______________ reasoning.
    Answer:
    inductive, deductive
    See Ch. 1





  6. T/F: Experimentation is only one part of the scientific process, but it is a very important step because it ensures that hypotheses can be confirmed with certainty.
    Answer:
    False
    gives the investigator a systematic, unbiased result (also, can't prove hypotheses to be true, only false)
    See Ch. 1





  7. T/F: A hypothesis must be testable to be scientifically valid. Being testable means that if the hypothesis is disproven the experiment was a failure.
    Answer:
    False
    only a controlled experiment can indicate whether the hypothesis is correct or incorrect
    See Ch. 1





  8. Radon is a radioactive gas that seeps into homes from the soil. It is thought to be a leading cause of lung cancer. A research team investigates this theory. They gather large amounts of data on basement radon concentrations and lung cancer rates and conclude that the more radon there is, the more likely is lung cancer. After the study is published, other researchers criticize it by asserting that the studied neighborhoods with higher radon concentrations also have a higher percentage of old people and a higher percentage of cigarette smokers than the low-radon neighborhoods. Both advanced age and cigarette smoking increase the risk of lung cancer. This criticism, if correct, shows that the radon study suffered from:
    Answer:
    C. uncontrolled variables
    See Ch. 1
    1. a lack of replication
    2. an unfalsifiable hypothesis
    3. uncontrolled variables
    4. nonsystematic observation
    5. a small sample size





  9. Why are biologists so interested in chemistry?
    Answer:
    Chemicals are the fundamental parts of all living things.
    See Ch. 2





  10. A particular carbon isotope has an atomic number of 6 and an atomic weight of 14. What is the respective number of neutrons, protons, and electrons it has? Two atoms of the same element must have the same number of ____________.
    Answer:
    8,6,6
    protons
    See Ch. 2





  11. T/F: An uncharged atom of nitrogen (atomic number = 7) has 7 protons and 7 electrons.
    Answer:
    True
    See Ch. 2





  12. The chemical bonding and reactivity characteristics of an element depend mostly on the:
    Answer:
    A. number of electrons in its outer shell
    See Ch. 2
    1. number of electrons in its outer shell
    2. number of electron shells present in the atoms
    3. mean energy level of its electrons
    4. degree to which it has more or fewer electrons than protons
    5. number of protons plus the number of neutrons





  13. For most atoms, a stable configuration of electrons is attained when the atom:
    Answer:
    D. has 8 electrons in its outermost shell
    See Ch. 2
    1. has as many protons as neutrons
    2. has moved all its electrons to its outermost shell
    3. achieves a zero net charge
    4. has 8 electrons in its outermost shell
    5. none of the above





  14. Please describe the difference between an ionic bond, a covalent bond, and a hydrogen bond.
    Answer:
    ionic bond: attraction between atoms that have opposite charges
    covalent bond: Two or more atoms share electron pairs.
    hydrogen bond: The partial charges on a water molecule cause electric attraction/repulsion
    partial opposite charges on molecules come close enough to attract each other
    Water molecules have a polarity that allows them to bond to each other with loose bonds
    See Ch. 2





  15. What is the process by which cells link monomers together to form polymers? Is water consumed or produced in this reaction? What is the process by which cells break polymers up to form monomers? Is water consumed or produced in this reaction?
    Answer:
    dehydration synthesis, produced
    hydrolysis, consumed
    See Ch. 3





  16. Generally, animals cannot digest the linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?
    Answer:
    Microorganisms in their digestive tracts hydrolyze the cellulose to glucose.
    See Ch. 3





  17. The four main categories of macromolecules in a cell are:
    Answer:
    C. proteins, nucleic acids, carbohydrates, and lipids
    See Ch. 3
    1. proteins, DNA, RNA, and steroids
    2. monosaccharides, lipids, polysaccharides, and proteins
    3. proteins, nucleic acids, carbohydrates, and lipids
    4. nucleic acids, carbohydrates, monosaccharides, and proteins
    5. RNA, DNA, proteins, and carbohydrates





  18. A glucose molecule is to starch as:
    Answer:
    D. a nucleotide is to a nucleic acid
    See Ch. 3
    1. a steroid is to a lipid
    2. a protein is to an amino acid
    3. a nucleic acid is to a polypeptide
    4. a nucleotide is to a nucleic acid
    5. an amino acid is to a nucleic acid





  19. In what polysaccharide form do plants store sugar to be available later for energy? In what polysaccharide form do animals store sugar in their muscles and livers to be available later for energy?
    Answer:
    starch, glycogen
    See Ch. 3





  20. A fatty acid containing at least two double bonds is called _______________. Please describe how fatty acids are related to fats (in particular, describe the chemical makeup of fat).
    Answer:
    poly-unsaturated
    triglyceride: glycerol + 3 fatty acids = fat
    See Ch. 3





  21. Although, like Calvin, you may choose to refuse to answer this question, if you do decide to answer it for the extra-credit, then please list three things that you like about the course so far (and want to see more of) AND list three things you don't like about this course so far (and don't want to see any more of).
    Answer:
    Student answers only.
    Student answers only.