SCI 135 - First Exam Spring 2020
Answer Key


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 order to be scientifically useful, a hypothesis should

___B___                    a.  Be completely logical                 b.  Lead to predictions
                                  c.  Give measurable results             d.  Be clear to everybody
                                                e.  Get you lots and lots of money

                     ...the other features are useful, but if you can't make predictions, you can't test.

                        2.  Evolution is mostly driven by

___C___                    a.  Changes in genetics                    b.  Continuous improvement
                                  c.  Changes in conditions                d.  Whatever is needed
                                                            e.  Nasty evil scientists

           's the conditions that select the features that will help the survivors to survive
                             and reproduce, and so on in offspring that inherit useful features...

 3.  Molecular clocks get their time gaps using   

___D___                    a.  Radioactive materials                 b.  Changes in chemistry
                                  c.  Numbers of generations             d.  DNA point mutations
                                                            e.  Tiny little stopwatches

                     ...when populations stop breeding together, over time each group accumulates
                         its own unique mutations over time - more time = more mutation differences.

4.   The classification system called cladistics puts its “branchings” on
                        family trees at the point of

____B_____              a.  Common ancestors                     b.  Critical feature appearances    
                                  c.  Changes in DNA codes              d.  New Kingdom formation
                                                            e.  Where the splits are

           's just a different way of seeing how evolution of new groups can be put together.

                  5.   Which is an example of spontaneous generation?

____D_____              a.  Turkeys appearing in the Northeast            b.  Bacteria spreading through a hospital  
                                  c.  New leaves growing in the springtime       d.  Rotting compost turning into slugs
                                                          e.  Isn’t that where things catch on fire-?

            things from non-living sources - the compost is dead stuff.


                  6.  Why is it a mistake to take results as proof?    (assuming a well-designed experiment)

                                  a.  You might have measured it wrong
                                  b.  Another hypothesis might explain the same results
___B___                    c.  Your test might not be reproducible
                                  d.  Peer review will not support that interpretation
                                  e.  You’ll be scolded by the Science Police

           're basically testing an explanation, and there could be a better one...


                   7.  Using lots of subjects in an experiment reduces the effect from

___D___                    a.  Quantitative factors                     b.  Qualitative factors
                                  c.  Artifacts                                       d.  Chance
                                                            e.  Not enough subjects

                     ...the fewer subjects, the better chance that you can get a very unlikely result that will
                          skew everything.


                   8.  Generally, in a food chain

____B_____              a.  Both energy and material get recycled          b.  Material only gets recycled
                                  c.  Energy only gets recycled                             d.  Neither energy nor matter gets recycled
                                                                             e.  Um, there’s food-?

                     ...materials get used, broken down, and the pieces can be put back together.  Energy gets lost on
                           every transfer as heat, until it's all gone...


                        9.  In an ecosystem, which is a first-level energy transformation?

___A___                    a.  Photosynthesis                            b.  Aerobic respiration
                                  c.  Anaerobic respiration                 d.  Glucose breakdown
                                             e.  Whatever’s at the top of the list

            takes energy from the environment (first level, in this case light) and transforms it into more usable
                               energy (the bond energy holding glucose together).


                        10.  Homology in molecules is based upon comparing

___C___                    a.  All of the atoms                           b.  Overall charge
                                  c.  The sequences                             d.  Their toxicity
                                                            e.  Their…bones?

                     ...homology compares internal structure - in proteins and DNA, that's the sequence of the components.


                        11.  All of the energy-using chemical reactions in a system are together called

____D_____              a.  Reproduction                                b.  Production
                                  c.  Digestion                                      d.  Metabolism
                                                            e.  A big pile o’ stuff

                     ...match the definition with the term.


                        12.   Butterflies and birds both fly with wings, but the wings’ structures are
                                                totally different, making them

____B_____              a.  Homologous only                            b.  Analogous only
                                  c.  Both homologous & analogous       d.  Neither homologous nor analogous
                                         e.  Ennielogous, meenielogous, minielogous, mologous...

                     ...matching function = analogous, but not similar structures = not homologous.

SHORT ANSWER.   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.  What is the current best definition of a species?

       ...a group that, in natural conditions, only breeds within that group.

2.  For two of the three basic levels in food chains (consumers, decomposers, producers), tell which one you’ve picked and briefly explain its role in the chain.

PRODUCERS Moves environmental energy into usable fuel molecules
CONSUMERS Gets their energy from already-made fuel molecules


Recycle material components to producers

3.  Give two different reasons why a hypothesis would need a field test to be tested.

Too expensive to duplicate conditions

Not possible to duplicate conditions

Not ethical to remove specimens

4. Put the following groups in order from the largest to the smallest:  Class, Family, Genus, Kingdom, Order, Phylum, Species, Subphylum, Superfamily.

1 Kingdom

4 Class

7 Family

2 Phylum

5 Order

8 Genus

3 Subphylum

6 Superfamily

9 Species

5.  Briefly explain the hypothesis of ontogeny recapitulates phylogeny.

       ...the development stages of an embryo (ontogeny) replays (recapitulates) the evolutionary stages of the species (phylogeny).

6.  A gene is a code made of DNA.  What exactly is made using the code?

       ...particular types of proteins.

7.  Briefly explain how basic respiration works in any living system. is moved from the bonds of one molecule (usually glucose) to the bonds of more usable molecules (usually ATP).

8.  In an experiment, what is an artifact?'s a result not from the hypothesis but produced by something in the design of the experiment itself.

9.  Put this list in order so that each level contains the previous one - cells, organs, organism, tissue.





10.   Briefly explain how each would work in a human drug trial:

Blind        People receiving treatment don't know if it's
         real or a placebo

Double     Blind, but also people administering treatment
Blind            don't know if it's real or placebo.

11.  Two different types of ways to make indirect observations (NOT looking for examples here!) -

Using someone else's observations

Using devices to bserve things beyond human senses

12.  In academic science, what is the most common form of peer review?

       ...reviewers go over the written article when it's submitted for publication.

13.  Give the definition of colonial organism.

       ...species that is always found as groups where individuals in the groups do different jobs to support the groups.

14.  What are the two beneficial effects that asexual reproducers get from producing huge numbers of offspring?

Can spread them out so changes don't reach them.

If significant changes are mostly mutations, increases the odds that rare useful mutations will happen.

 15.  If a scientist believes that a group is not classified properly -

What are            Change the classification
they easily               level / group designation.
to do?

What are they     Change the name
generally not
        given to the group.
allowed to do?

16.   What is a basic purpose of a control test?  (Don’t give a definition here!) uses a comparison to see if your variable is really doing something to the results.


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.  Answer for sexual reproduction -

BASIC                     Offspring are a genetic mix from 2 sources
           (Does not require 2 parents or male-female mating)

STRENGTH            Much more variation in offspring
(COMPARED          (Good when responding to changing conditions)

WEAKNESS           Can't actually make copies of well-adapted individuals
(COMPARED           (Not actually reproduction)

2.  For four of the six basic Kingdoms of Life, give the name of the Kingdom and enough features to clearly set that Kingdom's members apart from those of the other five.


Prokaryotes found in most "normal" environments


Prokaryotes found mostly in "extreme" environments


Eukaryotes, single-celled or very simple multicelled algae


Eukaryotes, multi-celled photosynthesizers

Eukaryotes, multi-celled, digest and absorb from internal spaces.  Usually can move.

Eukaryotes, usually multi-celled, digest and absorb across outer surface.  Usually a network of thin fibers.

3.  Put these in order so that each later level contains the earlier ones: 
            Community, Ecosystems, Individuals, Populations.






4.  Give two different rules that apply to each specifically in binomial nomenclature:


The Genus name

Always capitalized


Means nothing

by itself

Never capitalized


Considered "foreign" -

italicized or underlined

Abbreviated with first

initial and second word

5.  All for the most common isotope –

How many            9 -matches Atomic
       protons?           Number.




Number 9

How many        10 - rounded off Atomic
neutrons?         Weight minus protons.

How many         9 - matches protons.
electrons? (Uncharged form)

Column 7  Normally a minus-one ion,
needs and electron to fill outer shell to 8


6.   For viruses -

2 Features they have that are also found in all living things -



2 Features all living things should have that viruses do NOT have -


Metabolism in free form.

Interaction with environment.

Growth and development.


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.

Where were environments based on chemosynthesis discovered?  Three Points.

What is the main “working fuel” of pretty much ALL living things, actually USED to supply energy when needed in cells?  Three Points.

What generally determines what the “typical” number of offspring produced at a time for a species?  Three Points.

Redi’s first experiment set-up – what did folks say was wrong with it?  Three Points.

What particularly makes a study triple blind?  Three Points.

Who was Karl von Linne?  Three Points.

What basic body form shows up in a huge number of unrelated groups?  Three Points.

What level is now considered above Kingdom?  Three Points.

Where did Mendeleev (the Periodic Table guy) start out as a kid?  Three Points.

Why did chemists invent the atomic mass / weight measurements?  Three Points.

SCI 135 

Michael McDarby