Dr. Reichler’s Bio 301M MWF 9-10am Print
Exam #3 May 3, 2006
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. What part of human fear is genetically determined, and what part is
environmentally determined? (8 pts)
Experiments show that we have an
ingrained, genetically determined, fear of certain shapes, and other
experiments show that what we fear can be manipulated by what we learn
2. If adopted children have similar abilities for playing Scrabble as
their adopted parents, would this indicate a genetic or environmental
basis for Scrabble ability? (8 pts)
Environmental, with no genetic
relationship to their parents, the children must be picking up these
skills from the environment.
3. Give a specific example of an environmental factor that affects
human behavior but cannot be changed by the individual. (8 pts)
Things that occur in the womb or
early childhood such as the number of older brothers.
4. Does the gap at the ends of DNA occur on the leading or lagging
strand? Explain. (4 pts)
Lagging strand. DNA polymerase
moves away from the ends on the lagging strandmaking it unable to
replace the RNA primer.
5. Could insurance companies use telomere length as a reliable
determining factor when issuing life insurance? Why or why not?
Yes, studies in humans showed that
people with shorter telomeres were more likely to die. Telomeres
get shorter by age, but also by DNA damage.
No, while there is a general
correlation within one person’s lifetime of telomere length and age, it
is difficult to make comparisons between people. Also, different
parts of the body have different length telomeres.
6. Describe two situations that would cause someone to have short
telomeres. (8 pts)
Age causes shorter telomeres due to
repeated DNA replication. Damage to DNA also leads to short
7. Would a virus that infected a cell with very short telomeres be able
to replicate? Why or why not? (4 pts)
No, a cell with short telomeres would
be inhibited from replicating DNA.
Yes, an RNA virus could get its
genetic material copied because short telomeres would not effect RNA
8. Is access to plentiful food enough to increase the carrying capacity
of a species? Why or why not? (8 pts)
No, removal of waste and available
space are also critical factors in determining carrying capacity.
9. What evidence indicates that the avian flu is not being transmitted
by wild migrating birds? (4 pts)
Avian flu movement has moved across,
or in different directions, from many migration patterns. While
some migration patterns go from Asia to the US, the avian flu has not
moved into the US.
10. Why is someone who is infected with both human and avian flu
strains especially dangerous for the rest of the human population? (8
When two strains of the flu infect
the same cell, the strains can exchange genetic information, and in
this case, might form a highly virulent flu with easy transmission
11. Why would cutting down trees increase global warming? (8 pts)
Plants use CO2 from the
atmosphere. Removing plants would decrease the removal of CO2
from the atmosphere.
12. What does data about past climate change tell us about our current
situation? (8 pts)
Samples from ice cores have shown
several coincidences of increased CO2 levels and temperature.
13. Would you expect there to be more elk or wolves in Yellowstone
NP? Explain. (8 pts)
Elk. The wolves are secondary
consumers, and the elk primary consumers. Because of the loss of
energy as it moves through each consumer there are typically less
consumers at higher levels.
14. When studying the effects of reintroducing wolves to Yellowstone
NP, why did researchers measure the depth of creek and river gullies?
They hypothesized that the wolves
were causing the elk to avoid areas with low visibility such as deep
Bonus: Are differences in
finger length thought to be related to a cause or effect of sexuality?
Since these differences occur in the
womb, they cannot be an effect of sexuality.