Dr. Reichler’s Bio 301M MWF 9-10am Print
Exam #1 February 14, 2007
Read each question carefully and don’t hesitate to
ask if a question seems unclear. If possible, answer each
question in the space provided, but if needed, continue on the
back. If you use a drawing as part of your answer, be sure to
also include a written explanation. These questions have specific
answers, although for some, more than one answer is possible. To
receive full credit you must clearly and fully answer the question
being asked. This exam is worth 103 points with the points for
each question noted in parentheses.
1. Using rules one and two of Strong Inference answer the following
question: Who are people in the Middle East most closely related
Should propose at least two
hypotheses and one experiment to eliminate the hypotheses. For
example: Hypos- Middle Easterners are most closely related to
Europeans. Middle Easterners are most closely related to
Asians. Middle Easterners are most closely related to
Africans. Expt- Compare the mtDNA od people from these regions
and see who has the fewest differences with Middle Easterners.
2. You read a report stating that introducing wolves into Yellowstone
NP has increased the number of fish in the streams. The
researchers measured the number of fish currently in the streams.
Did these researchers use Strong Inference? Why or why not? (6pts)
No. Because they did not try to
disprove any hypothesis, they only have data from the current
time. OR They did not get reliable results because they
have no controls. OR They only had a single hypothesis.
3. Why do you have more of your mom’s DNA than your dad’s DNA? (6pts)
MtDNA is inherited only from mom, so
each of us inherits just a little more DNA from her.
4. Some organisms have much more DNA than humans do. Does this
mean that they can make a greater diversity of proteins than humans
can? Why or why not? (8pts)
Not necessarily. They may have
more non-coding DNA.
5. Differently from most people, you find that the time it takes Frank
to find a snake in a background of flowers is the same as the time it
takes him to find a flower in a background of snakes. Can this
difference between Frank and most other people be attributed to a
difference in DNA? Why or why not? (6pts)
Yes. Most humans have some
inherent ability, some genes that are inherited, to more rapidly detect
certain threats such as snakes or spiders. Frank must lack some
of these genes.
6. Both humans and wolves live in groups. How is the advantage
gained from forming groups different between humans and wolves? (8pts)
Human groups give protection,
probably from other humans. Wolf groups are better able to
capture prey- obtain food.
7. Can measuring how long an individual lives be used to determine
their evolutionary success? Why or why not? (8pts)
No. Evolutionary success is
measured by passing on genes- having offspring and those offspring
reproducing etc. Living a long time may or may not be an
indication od number and fertility of offspring.
8. If the mutation rate of mitochondrial DNA were 1 mutation every
500,000 years (this is much longer than the actual rate), would you be
able to determine the difference between the “out of Africa” and
multiregional hypotheses? Why or why not? (8pts)
No. The out of Africa
hypothesis states that humans have a common ancestor about 100,000
years ago. If the mutation rate was 1 per 500,000 years, then
there would be no way to detect recent differences in people’s DNA.
9. When researchers compared individual’s mitochondrial DNA, they found
people from different geographic locations with similar mitochondrial
DNA sequences. What does this indicate about our ancestors’
They must have commonly
migrated. The spread of different DNA throughout the planet shows
this pattern of ancient migration.
10. In the experiment where the researchers shocked the participants
depending on which picture they were shown. Did individuals of
the same skin color give similar results to snakes or flowers?
As flowers. For flowers, fear
irrelevant, and people of the same skin colors, the nervousness
desisted after the shocking, negative reinforcement, stopped.
11. When researchers were studying the effects of the reintroduction of
wolves, why did they measure the depth of gullies where streams were
They were looking to see if wolves
had changes the elks behavior by changing where the elks were
feeding. Deep gullies are considered high risk areas for the elks
as they can be easily ambushed by the wolves in deeper gullies.
12. Would you expect there to be more wolves or elk in Yellowstone
NP? Why? (6pts)
Elk. They are secondary
consumers, so the elks eat plants, use most of that energy for living
and only a fraction of the energy the elks eat is available for the
wolves. So less energy available limits the wolf carrying
13. How could researchers determine an animal’s response to the mirror
test without needing to manipulate the animal (by simply observing the
By observing if they act differently
than when presented with a “stranger”. If the individual
recognizes themselves, they would act differently than when they see
14. How could we increase the carrying capacity of humans on earth?
By reducing the resources we use, OR
by more effectively removing waste products.
Bonus: Over the same period of time, why would the number of
mutations present in nuclear DNA be higher than in mitochondrial
DNA? (3 pts)
Because the nuclear DNA has more
non-coding DNA. Mutations in coding regions are typically fatal,
and therefore not passed on. So since mtDNA has very little
non-coding DNA, the number of mutations for a given time that get
successfully passed on would be lower.