Download Use the following information for the NEXT 10 QUESTIONS

BIOL 1114
EXAM2 (No Star Form)
21 October 2002
Use a #2 pencil to fill in the information portion of your NCS answer sheet including the appropriate circles
(bubbles). Write “NO STAR FORM” above your name in the margin of your answer sheet. Read all questions
and answers carefully before choosing the single BEST response for each question. Feel free to ask the
instructor for clarification. Really, we aren't kidding!
1. There is evidence to suggest that in people with Alzheimer’s disease (senile dementia), the
neurotransmitter acetylcholine is less available in many areas of the brain. If this hypothesis were true, you
would correctly predict that in affected areas of an Alzheimer patient's, brain ____.
a) neuron to neuron communication would decrease
b) neuron to neuron communication would increase
c) neurotransmitter concentration in the synapses would increase
d) neurotransmitter reception by the postsynaptic neuron would be blocked by acetylcholine
e) neurotransmitter reception by the postsynaptic neuron would increase
2. Physostigmine (a product of the calabar bean) has been investigated for treatment of people with
Alzheimer’s disease. You would correctly hypothesize that this has been done because physostigmine
_______.
a) can cause paralysis, which stimulates the brain
b) prevents muscle contraction so that the person who is sick can be more relaxed
c) stimulates acetylcholinesterase release in the synapse
d) keeps Na+ gates of axons permanently open
e) would prolong the action of acetylcholine in the synapses of the affected part of the brain
3. Ms. Evil is trying to develop a toxin that would affect the nervous system of her neighbor’s dog, Boof, who
barks for hours at a time. She hypothesizes that if she could develop a toxin that would just affect the muscle
bands that are the vocal cords necessary for barking, she could get some sleep. She develops a compound
that causes Na+ gates in axons to stay open. You correctly predict that when Ms. Evil injects Boof with this
compound (through a hole in the fence) _____________.
a) action potentials in presynaptic neurons could still be measured
b) Boof’s vocal cords would continue to contract normally
c) transmission of an action potential across the synapses would continue
d) Na+ concentrations inside and outside the cell membrane of the axon would become approximately equal
e) (a), (c) and (d) would all occur
4. The next morning, Ms. Evil is surprised to see that Boof is quietly stretched out on the ground next to the
fence. Alas, Boof is now silent and dead. You would correctly predict that Boof died of______.
a) barking to exhaustion
b) seizures
c) paralysis of breathing muscles
d) fear of Ms. Evil
e) a life-threatening heat gradient between the dog and the fence
5.
a)
b)
c)
d)
e)
Choose the sequence below that represents the correct size order from smallest to largest.
Na+ - axon - neuron - Na+/K+ pump
neuron - Na+/K+ pump - Na+ - axon
axon - neuron - Na+ - Na+/K+ pump
Na+ - Na+/K+ pump - axon - neuron
Na+/K+ pump - neuron - axon - Na+
6. BoTox is a protein toxin obtained from the bacterium Clostridium botulinum. BoTox is used in small
quantities in the cosmetic industry to lessen frown lines and certain wrinkles by injecting it directly into the
muscles that cause frowning or wrinkles. It has also been used to reduce sweating in people with the
condition of hyperhidrosis (excessive sweating). In large quantities it is potentially lethal to humans. It
causes general paralysis and respiratory failure followed by death. Which of the following mechanisms would
you correctly predict for the action of botulism poisoning?
a) Inhibiting the enzyme acetylcholinesterase in the synapse
b) Blocking the release of a neurotransmitter
c) Mimicking a neurotransmitter (e.g., acetylcholine)
d) Stimulating the release of a neurotransmitter
e) None of the above
7. A pharmacologist is searching for an antidote to the botulism toxin. He should look for a compound that
acts in which of the following ways?
a) blocks acetylcholine receptors
b) breaks down acetylcholine in synapses between neurons and muscles
c) causes sodium/potassium pumps to increase the sodium/potassium gradients across the neuron
membrane
d) enhances acetylcholine secretion into synapses between neurons and muscles
e) causes gated sodium channels in the neuron to remain open all the time
8. Bacterial cells found on the surface of your skin could easily be distinguished from the skin cells because
skin cells have __________ and bacterial cells do not.
a) cell walls
b) ribosomes
c) mitochondria
d) cell membranes
e) DNA
9. Marine iguanas are vegetarians that feed mainly in the intertidal zone. Only large male iguanas go beyond
the breakers (waves) and feed underwater in the cold water around the Galapagos. Which one of the
following would allow the larger and not the smaller individuals to feed underwater in the cold water? Recall
that iguanas are ectothermic poikilotherms.
a) The larger males have a larger surface area to volume ratio than the smaller iguanas
b) The larger males have a smaller surface area to volume ratio than the smaller iguanas
c) The larger males have broader tails than the small iguanas
d) The larger males have a shorter nose than the small iguanas
e) The larger males have longer and sharper claws than the small iguanas
Use the following information for the NEXT 10 QUESTIONS
In the Sonoran Desert of Mexico, Dr. Ted Fleming recently made some observations concerning the
relationship between a species of moth (Senita moth) and a cactus species (Senita cactus). The cactus
blooms (flowers) during the spring and summer only. At this time, successive generations of Senita moths
pollinate the cactus flowers as they move from flower to flower feeding on the nectar contained in the flowers.
They also lay their eggs on the flower at this time. Once a flower is pollinated it will produce marble-sized red
fruit, some of which is eaten by the Senita moth larvae (hatched eggs). These larvae will form pupae that
hatch as adult moths. The larvae that come from eggs late in the summer do not have time to pupate and
mature into adult moths because the cactus stops fruiting. Therefore they bore into the cactus branches and
wait for spring when the weather is warmer and there is more food available. The Senita cactus blooms are
open only at night, when moths are active. When the weather starts to cool at the end of summer, bees that
feed early in the day may find flowers still open. But in warmer weather, at the height of the blooming season,
alas, all the drinking establishments (i.e., flowers) close at dawn. Thus pollination is totally dependent on the
Senita moth.
10. The situation described above is an example of __________.
a) a burst of ATP
b) coevolution
c) adaptive radiation
d) founder effect
e) All of the above (a-d).
11. In order for the Senita cactus to conduct aerobic cellular respiration it needs which of the following?
a) carbon dioxide and water
b) pyruvate and carbon dioxide
c) sunlight and oxygen
d) glucose and oxygen
e) None of the above because plants do not do aerobic cellular respiration.
12. Cacti are photoautotrophic organisms, therefore they use sunlight to convert ________ into ________.
a) protons;
pigments
b) glucose and oxygen;
carbon dioxide and water
c) chloroplasts;
glucose
d) carbon dioxide and water;
glucose and oxygen
e) oxygen;
ATP and water
13. Excluding water, the bulk of the cactus stem is made up of mostly carbon-based material. This carbonbased material is derived primarily from __________.
a) chemiosmosis in the mitochondria
b) carbon dioxide that was converted into pyruvate in the Krebs cycle
c) the uptake of carbon dioxide from the soil by glycolysis
d) the uptake of carbon dioxide from the atmosphere and fixation by the Calvin cycle
e) the splitting of water in Photosystem I
14. A mutation, which resulted in the thylakoid membrane becoming leaky (permeable) to H+ (protons),
occurred in a Senita cactus pollen grain that eventually fertilized an egg. When this fertilized egg developed
into a young cactus, which expressed this mutation, you would correctly predict which one or more of the
following to occur?
a) decreased ATP production in the chloroplast
b) decreased glucose production in the chloroplast
c) decreased CO2 uptake in the chloroplast
d) All of the above (a-c) are correct predictions.
e) Only (a) and (c) are correct predictions.
15. When will O2 production in the cactus plant be the greatest?
a) warm day
b) warm night
c) cool day
d) cold night
e) Never -plants do not produce O2.
16. Which one or more of the following could limit the rate of photosynthesis in the cactus plant?
a) air temperature
b) availability of water
c) availability of CO2
d) amount of sunlight
e) All of the above (a-d) could limit the rate of photosynthesis.
17. Cactus cells found on the legs of a Senita moth could easily be distinguished from the moth cells
because plant cells have ___________ and animal cells do not.
a) mitochondria
b) Golgi bodies
c) cell membranes
d) chloroplasts
e) vesicles
18. If a piece of Senita cactus were placed in a hypertonic solution (a solution saltier than the cytoplasm of
cactus cells), initially water would _________.
a) move into the cells by osmosis, causing them to swell
b) move out of the cells by osmosis, causing them to shrink
c) move into the cells by osmosis, causing them to shrink
d) move out of the cells by osmosis, causing them to swell
e) move into and out of the cells at the same rate, resulting in no change in size or weight
19. The cactus fruit appears red to us because it reflects mainly ________ light that is absorbed by
photoreceptors in our ________.
a) blue;
cone cells found in the mitochondria
b) red;
rod cells found in the eye
c) yellow;
cone cells found in the eye
d) red;
cone cells found in the eye
e) blue;
rod cells found in the eye
Use the following information for the NEXT 5 QUESTIONS
In 1883, Thomas Englemann used a prism to project the full spectrum of visible light along the length of a
filamentous (resembles a strand of hair) green alga (singular of algae) that contains chlorophyll a and b. This
experimental set-up exposed sections of the alga to different wavelengths of light (ranging from violet through
red). He then placed aerobic bacteria in the container with the alga. These bacteria require oxygen and
accumulated in the areas with higher oxygen concentration. This allowed Englemann to determine which
sections of the alga were producing the most oxygen and thus which wavelengths of light resulted in the
highest rate of photosynthesis.
20. Under the circumstances described above, what is the direct source of the oxygen that is required by
the bacteria?
a) splitting of CO2 by the Calvin cycle
b) splitting of CO2 by the Krebs cycle
c) splitting of H2O by photosystem II
d) electron transport chain in the mitochondria of the algae
e) electron transport chain in the thylakoid membrane of the algae
21. For what process do the bacteria directly need oxygen?
a) Glycolysis
b) cellular respiration
c) photosystem II
d) Calvin cycle
e) photosystem I
22. Where would you correctly predict that Englemann found the most bacteria accumulating?
In the areas of algae exposed to _________ light.
a) orange
d) red
b) yellow
e) (b) and (d)
c) green
23. If Englemann had used a red alga in the experiment where would you correctly predict the fewest
bacteria to accumulate? In the areas of algae exposed to _________ light.
a) orange
b) blue
c) green
d) red
e) yellow
24. Englemann's experiment allowed him to determine the relationship between wavelength of light and
photosynthesis by the alga. To plot data from this experiment you would correctly place ________ on the X
axis and _________ on the Y axis.
a) wavelength of light;
color of algae
b) number of bacteria;
wavelength of light
c) color of algae;
wavelength of light
d) wavelength of light;
number of bacteria
Use the following information for the NEXT 4 QUESTIONS.
A scientist observes that about 95% of the individual grasshoppers of a particular species are green, similar to
the plants that they live on. He hypothesizes that these grasshoppers are green because they are harder for
visual predators to detect against the green background of plants. To test this hypothesis, the scientist
conducts an experiment. He marks 100 green grasshoppers with spots of red nail polish, another 100 green
grasshoppers with transparent (colorless) nail polish, and a third 100 green grasshoppers are left unmarked.
Twenty-five (25) of each type are placed in each of 4 field plots in different locations, which are videotaped
over the course of a day to document predation (without the presence of the scientist to influence predator
behavior). This whole experiment is repeated on 3 days and the results compared. He predicts that, if the
hypothesis is correct, natural predators such as birds and praying mantises (which are also green insects) will
capture more of the red-spotted grasshoppers than the control grasshoppers. He combines results (below)
for all 4 plots and 3 days, after determining that there were no statistical differences between days or plots.
Grasshopper group
Red nail polish
Transparent nail polish
Unmarked
Percent captured by birds
42
16
15
Percent captured by praying mantises
14
13
17
25. This is an example of a ____________ experiment in which ___________ is the dependent variable.
a) correlational/observational; percent grasshoppers captured by birds
b) correlational/observational; color of nail polish
c) controlled;
percent grasshoppers captured by a predator
d) controlled;
color of nail polish
e) controlled;
type of predator (bird or mantis)
26. In hypothesizing that “grasshoppers are green because they are harder for visual predators to detect
against the green background of plants”, the scientist really means that ____________.
a) the grasshoppers choose to be green because they know they will be eaten otherwise
b) natural selection against non-green grasshoppers keeps them (non-green) at a low percentage in the
population
c) grasshoppers mutate intentionally to become green so they can survive
d) there are no other possible explanations (hypotheses) for the green color
e) Both (a) and (d)
27. In order for birds or mantises to see a grasshopper, _____________________.
a) ions must be pumped across their neuron membranes
b) neurotransmitters must be secreted at synapses
c) light must reflect off the grasshopper
d) pigments in their eyes must absorb light to start (initiate) an action potential
e) All of these (a-d)
28. The results of the experiment __________________.
a) do not support the hypothesis
b) prove that predation by mantises has no effect on grasshopper populations
c) support the hypothesis for birds but not for mantises
d) prove that only birds prey on grasshoppers
e) Both (b) and (d)
Use the following information for the NEXT 7 QUESTIONS.
Sea slugs (snails without shells) inhabit various marine (ocean) communities. Their gills (gas-exchange
organs) are fingerlike projections on their dorsal side (back). Elysia spp. (sea slugs) live on well-lit coral reefs
and eat certain green seaweeds (algae). Rather than completely digesting the algae, their digestive tract
cells engulf (phagocytize) the chloroplasts and temporarily store them intact and fully functional in their gills,
while digesting the rest of the algae. The sea slugs thus have a green color similar to the algae they crawl
over and eat. Similarly, many corals (primitive invertebrate animals) contain symbiotic (living inside) intact
single-celled algae, rather than just their chloroplasts. Since it is possible for photosynthesis and respiration
to occur simultaneously, only the net release or consumption of CO2 and O2 by the slug/chloroplasts or
coral/algae pairs can be measured easily.
29. Ignoring the metabolism of the corals and sea slugs, compare the metabolic capabilities of the
chloroplasts inside sea slugs and the algae inside of corals.
a) The chloroplasts can conduct photosynthesis only, whereas the algae conduct both photosynthesis and
respiration.
b) Both the chloroplasts and algae can conduct only photosynthesis, not respiration.
c) The chloroplasts can conduct glycolysis and the Krebs cycle, but not electron transport; the algae can do
all three.
d) The algae can make sugars, but the chloroplasts cannot.
e) The algae produce O2, while the chloroplasts consume O2.
30. During the day, a sea slug containing chloroplasts would have ________________ an identical sea
slug lacking chloroplasts.
a) a greater net release of CO2 than
b) a greater net consumption of O2 than
c) a smaller net release of CO2 than
d) the same net release of O2 and consumption of CO2 as
e) Both (a) and (b).
31. At night, a coral containing algae would probably have ____________ an identical coral lacking algae.
a) a greater net release of CO2 than
b) a greater net consumption of O2 than
c) a greater net release of O2 than
d) the same net release of O2 and consumption of CO2 as
e) Both (a) and (b).
32. At night, a sea slug containing chloroplasts would have ________________ an identical sea slug
lacking chloroplasts.
a) a greater net consumption of CO2 than
b) a greater net release of O2 than
c) a smaller net consumption of CO2 than
d) the same net release of O2 and consumption of CO2 as
e) Both (a) and (b).
33. Suppose that some individual sea slugs of this species begin to inhabit and eat mainly red algae, while
most inhabit and eat mainly green algae, and that the two types of sea slugs rarely interbreed. If this situation
persists for many generations, you would correctly predict that populations of the two types of sea slugs
would _____________.
a) become genetically similar
b) become different species
c) become less well adapted
d) become unable to distinguish between colors of seaweed
e) Both (a) and (c)
34. Based only on the information above, which one or more of the following is a reasonable hypothesis to
explain the tendency of sea slugs to store chloroplasts?
a) Natural selection favors sea slugs with chloroplasts because these sea slugs are less visible to predators.
b) Natural selection forces each individual sea slug to become a separate species.
c) Natural selection favors sea slugs with chloroplasts because they can obtain energy from sugars made by
the chloroplasts.
d) Natural selection favors sea slugs with chloroplasts because they no longer need cellular respiration.
e) Both (a) and (c).
35. Sea slugs are hermaphroditic (they produce both eggs and sperm) but cannot fertilize their own eggs with
their own sperm. Which of the following sea slugs has the greatest fitness?
a) a large, colorful, robust sea slug who attracts 3 mates and produces 100 offspring, 10 of which survive to
reproduce
b) a small drab sea slug who attracts 1 mate and produces 30 offspring, 15 of which survive to reproduce
c) a large, colorful, robust sea slug who lives longer than all the other sea slugs born that year and who never
mates
d) a large, colorful, robust sea slug who lives a long time, mates once, but leaves no offspring
e) a sea slug who can crawl really fast and escape predators
Use the following information for the NEXT 5 QUESTIONS
Soapberry bugs are found in the southern U.S. including Oklahoma. They feed only on plants in the family
Sapindaceae by inserting their piercing mouthparts into the fruits and sucking the contents of the seeds. The
lengths of the “beaks” of these bugs reflect the size of the fruits on which they feed. Those populations that
feed on big fruits tend to have long beaks; those feeding on smaller fruits have short beaks. Equally
important, is the observation that soapberry bugs mate and lay their eggs only on the fruit they eat. In the
1950’s, horticulturalists brought three new species of Sapindaceae plants into the U.S. and soapberry bugs
began to feed on them. Since the introduced plant species had much small fruits than the native plant
species, Scott Caroll and Christin Boyd studied the changes that occurred in beak lengths of soapberry bugs.
They found that over time, those bugs living on the introduced plants (smaller fruits) had shorter beaks than
those living on native plants (larger fruits).
36. Scientists measured the genetic diversity of the introduced population of Sapindaceae when they were
first brought to the U.S. They found it to be far lower than that of populations of Sapindaceae plants in Asia
from which they were taken. Which of the following is the best hypothesis to explain this?
a) soapberry bugs and soapberry plants coevolved
b) Asian soapberry bugs are larger
c) the Sapindaceae plants brought to the U.S. represent a small founder population
d) mutations eliminated the genetic diversity
e) adaptive radiation caused mutations in the plant's genes and reduced the genetic diversity.
37. The differences in beak lengths between the bug populations living on native and non-native plants, can
best be explained by which of the following statements?
a) Mutations in the genes controlling the beak-length followed by natural selection, eliminated bugs with
longer beaks attempting to feed on smaller fruits.
b) Natural selection eliminated bugs with longer beaks that fed on smaller fruits followed by mutations that
resulted in shorter beaks.
c) Mutations for shorter beaks only, natural selection was not necessary.
d) The need for shorter beaks resulted in mutations in genes controlling beak-length.
e) The chance arrival of shorter-beaked bugs that fed on smaller fruits only
38. This evolution of beak lengths as a result of the introduction of new species of Sapindaceae plants has
been proposed as the cause for speciation in the bugs. Which of the following would you correctly
hypothesize is the cause of this speciation?
a) coevolution between the species of soapberry plants
b) that the bugs mate on the plants on which they feed results in reproductive separation of the bug
populations
c) founder effect increasing the number of bugs that eat plants
d) mutations in the soapberry plants
e) none of the above, soapberry bugs cannot become new species.
39. If speciation in the soapberry bug did occur, you could correctly state that adaptive radiation also
occurred if __.
a) coevolution occurred among the plants
b) one very large founding population was involved
c) different populations of soapberry bugs, that no longer bred with the other soapberry bug populations,
were found on the three different non-native species of Sapindaceae.
d) more of the same species of plants were brought from Asia
e) the beak lengths of all of the soapberry bugs were exactly the same
40. If adaptive radiation did occur, you would correctly predict that the fitness of individuals of the different
species would be ______.
a) highest among those individuals that fed on the largest fruit regardless of beak size
b) highest among those that bred with individuals that fed on different size fruits
c) highest when those that fed on the native species bred with those that fed on the introduced species
d) highest among those individuals that bred only with those that fed on the same type of fruit as themselves
e) equal among all individuals