BIOL 1114
Exam #2 (Preview) March 5, 2012
Use a #2 pencil to fill in the information on your NCS answer sheet. Put your O-Key Account Username in the
boxes indicated for LAST NAME and darken the appropriate circles. Write your Name (Last, First) and “Star” or
“NoStar” in the space above the boxes containing your O-Key Account Username. Darken the (S) or (N) in the
last column of the name circles. Enter the number 1212 and darken the corresponding circles in the first 4
columns of the “Student ID.” Failure to perform this correctly will incur a -10pt handling fee. Read all questions
and answers carefully before choosing the single BEST response for each question. Feel free to ask the instructor
for clarification.
Mosquito: http://www.umaa.org/images/mosquito.jpg source: http://www.umaa.org
Toxins: http://www.kingsnake.com/toxinology/images/neurotoxin_sites_of_action.jpg
source: http://www.kingsnake.com/toxinology/venomdoc/Venomdoc.html
Scientists wanted to determine whether mosquitoes have been bioengineered to produce toxins that affect normal
functioning of the nervous system. They start by collecting mosquitoes from several locations in the U.S. and identify all
the toxins found in them. After identifying all the toxins in American mosquitoes, the researchers consult the scientific
literature and choose four suspicious toxins for further study, and determination of their effects on the nervous system.
They expose rats to similar concentrations of the four toxins found in mosquitoes and measure the neuronal response.
Their data are summarized in the table below:
Toxin name
Neuronal effect
Maculotoxin
Blocks sodium channels
Latrotoxin
Increases acetylcholine release
Crotoxin
Reduces acetylcholine release
Phrixotoxin
Blocks potassium channels
A lab technician accidentally cuts his hand during the experiment, and is exposed to two toxins simultaneously. He reads
the labels of the toxins, and sighs in relief.
Madagascar is an island of the east cost of Africa. Among its plants, Madagascar is famous for its Baobab trees in the
genus Adansonia. Baobabs store water inside the swollen trunk (up to 120,000 litres) to endure the harsh drought
conditions particular to each region of the world where each species lives. All species occur in seasonally dry areas, and
are deciduous, shedding their leaves during the dry season. Eight species are known in the genus, six native to
Madagascar, one to mainland Africa and one to Australia. Within the Adansoni there is a striking diversity in floral
morphology. The continental African species is bat-pollinated, and has long flower stalks that only bats can reach;
whereas the Madagascar and Australian species are pollinated by hawkmoths and have long cylindrical flower buds that
are erect and therefore are only accessible by the long proboscis of hawkmoths.
Map: http://www.eoearth.org/files/124101_124200/124104/Website.Tsingy-Location-Map.jpg
Source: http://www.eoearth.org/article/Tsingy_de_Bemaraha_Strict_Nature_Reserve,_Madagascar
Tree: http://upload.wikimedia.org/wikipedia/commons/thumb/a/a8/Adansonia_grandidieri04.jpg/200px-Adansonia_grandidieri04.jpg
Source: http://en.wikipedia.org/wiki/File:Adansonia_grandidieri04.jpg
A single African species of Adansonia is ancestral to the six species of Madagascar Baobabs. One hypothesis suggests
that the ancestor of the six Madagascar species of Baobabs rafted over to Madagascar from Africa as seeds. Ecological
studies on the six species of Madagascar Baobab trees indicate that they live in distinct habitats on the island, occupy
distinct niches, and are isolated from other Baobab species on the island. Studies on the genetic diversity among these
species indicate that all six species diverged from their common ancestor at approximately the same time. Each species of
Baobab trees are pollinated only by a single species of hawkmoth, which specializes on eating a single species of Boabab
tree. Many Baobab trees use their swollen trunks to store water during dry conditions.
Rider, cactus, horse: http://writinghorseback.com/wp-content/uploads/2011/01/Rancho-de-los-Caballeros-CowgirlsSaguaro-cactus.jpg
Source: http://writinghorseback.com/2012/01/luxury-dude-ranch-vacation-at-rancho-de-los-caballeros-arizona/
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A saguaro cactus, a rider and a horse are shown in the Sonoran Desert. The rider is wearing sunglasses, and proclaims that
the green saguaro cactus appears reddish to him.
The summer’s average daytime high temperature in this southwestern desert is 42o C; the average nighttime temperature is
19o C. A saguaro cactus has a very shallow root system and can store up to 160 liters of rainwater. Excess time in the
desert sun presents a greater hazard (due to water loss) for the horse and rider than for the saguaro cactus plant. The ability
of the saguaro cactus to retain so much water in the desert heat is significant because water has a very high specific heat
(i.e., it can absorb a very high amount of heat before the actual temperature within the plant cells rises).
White-winged doves are prominent pollinators of the saguaro cactus. A new dataset finds that doves preferentially choose
cacti that are bright green in color over those that have a paler green color.
Doves: http://www.marietta.edu/~biol/biomes/images/desert/white-winged_dove_6368.jpg
Sources: http://bio.department.marietta.edu and http://schools.cajonvalley.net/webpages/tlee/science.cfm?subpage=253162
As you may recall, during our last evaluation episode, Star Fleet’s Department of Astrobiology was studying some alien
life forms (ALFs) discovered during their voyages to other planets. Along with the humanoid ALF’s, the scientists also
collected what appeared to be alien plant life forms (APLFs). The specimens thus far revealed that these too have a
metabolism and biochemistry that follow the same principles as Earth’s plants. You may also recall that the
atmosphere/climate of the planets Yap and Yam were:
Atmospheric/Climate Characteristic
Yap
(Home of ALF/APLF-1)
Yam
(Home of ALF/APLF-2)
Average temperature
37oC
32oC
Average O2 Concentration
21%
1%
650
510
Sun’s Primary wavelength (most plentiful)
Red Spectrum: http://science-edu.larc.nasa.gov/EDDOCS/images/Erb/Red_Spectrum.jpg
Green Spectrum: http://science-edu.larc.nasa.gov/EDDOCS/images/Erb/Green_Spectrum.jpg
Image Source: http://science-edu.larc.nasa.gov/EDDOCS/Wavelengths_for_Colors.html
The pitcher plant is insectivorous. In 1906 it was introduced from Canada into Ireland at several locations, all quite similar
in habitat, insect availability, climate, lack of herbivores, etc, yet each of these populations is genetically different from
the others and much more genetically similar than those in Canada.
Pitcher Plants: http://s0.geograph.org.uk/geophotos/01/15/62/1156280_9965b4a0.jpg
Source: http://www.geograph.org.uk/photo/1156280 use http://creativecommons.org/licenses/by-sa/2.0/
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