SCI 135 - Second Exam Spring 2016
Links connect to relevant parts of the online book.


On the line to the left, place the letter of the choice that best answers the question.
Three Points Each. NOTE: "e" answers are never the correct answer.

            1.  In which bond are electrons shared?

__________    a. Hydrogen         b. Ionic        c. Covalent         d. Osmotic
                                       e. Handcuffs for two wired to a battery

            2.  An unsaturated molecule would have

_______    a. More water             b. A double bond            c. Less water
                d. All single bonds            e. A definite lack of saturation

            3.  Which chemical process is essential in the digestion (breakdown) of food?

_______    a. Hydrolysis             b. Dehydration synthesis            c. Osmosis
                d. Ionic bonding                e. The creation of special sauce

            4.  The fluid mosaic model applies to

_______    a. DNA expression             b. Surface tension            c. Cell membranes
                d. Electron sharing                    e. Something really fancy

            5.  Which of the following is not a polymer?

_______    a. Protein         b. Nucleic acid         c. Starch        d. Sugar
                                e. Eenimer, meenimer, mynimer, mo...

            6.  An atom is most stable as an ion with a negative one ( - ) charge. How many
                            electrons should it have in its outer orbital?

________   a. 1         b. 8         c. 7         d. 3        e. Oh, that's what it meant.....

            7.  Which is best described as a phospholipid bilayer?

________   a. DNA         b. Cell membrane        c. Cell wall         d. Ribosome
                                                        e. A Twinkie

            8.  Steroid hormones belong to which class of organic molecule?

________   a. Lipids         b. Proteins         c. Carbohydrates        d. Nucleic Acids
                                            e. Pumped-up molecules

            9.  The pH of digestive juices in the intestine is between 7.5 and 8.5. Compared with a
                            neutral pH,
the concentration of  H+ ions should be

________ a. Higher         b. Lower        c. Equal         d. There's no way to tell
                            e. I saw this in the book - guess I should have figured it out...

            10. Sectioning involves

_______   a. Cell chambers         b. Cell walls         c. Thin slicing        d. DNA distribution
                                                    e. Our brains falling to pieces

            11. Polydehydrogenase would belong to which class of organic molecule?

________ a. Oils         b. Enzymes        c. Starches         d. Nucleic Acids
                        e. No, you're not supposed to recognize the word.

            12. In what kind of reaction could a molecule pick up 2 electrons?

_______   a. Hydrolysis         b. Dehydration synthesis        c. Oxidation         d. Reduction
                                                    e. A trip to the Atom Tavern


Answer any eight of the following questions for 4 Points Each.

Note: if you answer more than eight, only the first eight will be corrected.
You can get partial credit on these answers.

1.  In a container of pure water, explain what happens to the molecules as the temperature drops from 10o to 1o C.

2.  In photosynthesis, light energy is converted into what other form of energy?

3.  Non-coding DNA is actually a lot of different things. What are two?


4.  Lipid molecules are constructed from two basic parts. What are these molecule subunits?


5.  What exactly makes a molecule polar? (Not necessarily bipolar!)

6.  Explain what a codon is.

7.  What are two Kingdoms where virtually every species has a cell wall?


8.  What are the primary proteins that make our muscles move?


9.  For what two different, major reasons do plants produce starches?


10. Given here is one side (strand) of DNA. Starting with this strand, show:
Strand    T  A  A  T  C  G  A  C  C  T  A  T  C  T  C  A  A  T  T  G  C

                                                      Other DNA strand

11. Briefly explain why radicals are so chemically reactive.

12. You stir sugar into a glass of water.  What is the -

13. Label the following chemical reaction with the general terms for each part –
       A            +         B                      x           >                C

__________            ___________          ______________             _____________

14. Define these terms -


15. What, technically, is a gene?

16. Which property of water is it when water is "soaked up" by the cellulose of a paper towel?


Answer any four of the following questions for Eight Points Each.
Note: if you answer more than four, only the first four will be corrected.
You can get partial credit on these answers.

1.  Name the two basic types of cells, and give three sets of differences between them:




2.  Microscopes can be split into two main groups based upon either listed feature. For each feature, name the groups.
Nature of the
Imaging Beam
Interaction of Beam
with specimen

3.  Name and give a brief description for the four levels of protein structure.





4.  Give four rules from the Cell Theory.



5.  Using the numbers of bonds as a guide, fill in the symbols for either Carbon, Hydrogen, Nitrogen, or Oxygen.
          O                     O                                                            O

          O                     O                    O                     O

                                  O                    O                                         O

                                  O                     O

6.  What are three different biological uses for lipids?



7.  Give four different functions for some of the proteins found embedded in cell membranes.



Link to Answer Key


Answer as many as you are able. Wrong answers will not result in points being lost from the main exam. You can get partial credit on these answers.

Why are electron levels called shells? Three Points.

What’s the common term for ionically-bonded solids? Three Points.

In what ways can taking extra anti-oxidants be bad for us? Three Points each.

Why is it called pH? Three Points.

Why are insecticide molecules often similar to sex hormones? Three Points.

How might a plant respond to an alarmone signal? Three Points.

Most “traits” are multiple-gene traits. Why? Three Points.

One type of molecule has had many new functions discovered in the past 10 years or so – what molecule is it? Three Points.

Why did they call it junk DNA? Three Points.

When it was first discovered that sick people had lots of bacteria, where did folks think the bacteria had come from? Three Points.

What sort of commercial use is made with plasmids? Three Points.



SCI 135 

Michael McDarby