Biol 1114
EXAM TWO (NO STAR FORM)
March 6, 2000
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 the answer sheet. Read all questions
and answers carefully before choosing the single best response for each question. DO ASK your instructor
for clarification if you want it.
1. Enzymes are proteins. Which one of the following cell structures has protein synthesis as its primary
function?
a) Golgi body
b) plasma membrane
c) chloroplast
d) ribosome
e) mitochondrion
2. People with myasthenia gravis produce antibodies that destroy some of their own acetylcholine
(neurotransmitter) receptors. Which one of the following symptoms would you correctly expect to find in
myasthenia gravis patients?
a) seizures
b) rapid pulse
c) pupil contraction
d) diminished muscle contractions
e) inability to sleep
3. Physostigmine from the calabar bean, which causes pupils to become smaller, has been used to help
myasthenia gravis patients. The reason a small amount of this neurotoxin helps is
a) it inhibits acetylcholine receptors, causing increased muscle contraction.
b) it mimics acetylcholinesterase, causing decreased muscle contraction.
c) it inhibits release of acetylcholine, causing increased muscle contraction.
d) it inhibits acetylcholinesterase, causing decreased muscle contraction.
e) it inhibits acetylcholinesterase, causing increased muscle contraction.
4. Which one or more of the following would happen across a cell membrane without ATP energy inputs?
a) movement of water down a concentration gradient (from higher concentration to lower)
b) movement of sugar up a concentration gradient (from lower concentration to higher)
c) movement of water up a concentration gradient
d) movement of sodium out of a neuron during a resting potential phase (from lower concentration
to higher)
e) all of these (a-d)
5. A neurotoxicologist notices that a particular spider venom causes muscle paralysis (no voluntary muscle
contraction possible). She correctly hypothesizes which one or more of the following:
a) the venom increases acetylcholine concentration in synapses between neurons and muscles
b) the venom inhibits acetylcholine secretion into synapses between neurons and muscles
c) the venom mimics acetylcholine in synapses between neurons and muscles
d) both (a) and (c)
e) none of the above
6. A newly developed insecticide (bug killer) contains a substance that makes the membranes of neurons
that communicate with muscles extremely permeable to potassium ions (K+). Which one or more of the
following would you correctly expect to happen in an insect that had been exposed to this insecticide?
a) There will be intense muscle contractions.
b) There will be decreased muscle contractions.
c) There will be increased release of neurotransmitters from the axon bulb.
d) There will be decreased release of neurotransmitters from the axon bulb.
e) Both (b) and (d).
7. Just as a nerve cell begins to produce a nerve signal, it is poisoned with rotenone. It produces the nerve
signal, but cannot be stimulated to produce another. Which of the following is the most reasonable
hypothesis for this?
a) Sodium (Na+) cannot pass through because the sodium channels are blocked.
b) Potassium (K+) cannot pass through because the potassium channels are blocked.
c) The sodium-potassium pump cannot return the cell to its resting potential levels of Na+ and K+
because the cell lacks ATP
d) The sodium-potassium pump cannot return the cell to its resting potential levels of Na+ and K+
because the rotenone blocks the sodium and potassium channels.
e) There is insufficient sodium because rotenone interferes with sodium production.
8. Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived next to
each other in some parts of their ranges. However, recent bird books show them as eastern and western
forms of a single species, the yellow rumped warbler. The best evidence for this conclusion would be that
the two kinds of warblers
a) are almost identical in appearance.
b) live in the same area.
c) successfully interbreed.
d) are merging to form a single species.
e) live in different places.
9. If you wanted to distinguish plant cells from animal cells you would look for the presence of
a) membranes.
b) ribosomes.
c) proteins.
d) mitochondria.
e) chloroplasts.
10. The first finches that reached the Galapagos Islands were likely to be seed eaters. The best hypothesis to
explain why finches living on these islands today feed on a variety of food sources is natural selection
a) caused the genes for beak size and shape to mutate.
b) selected for variations in beak size and shape.
c) selected for survival of finches that had only one size and shape of beak.
d) allowed for longer beaks because the finches had more calcium in their diet.
e) caused the finches to gain an enzyme for the breakdown of seeds.
11. You are on an expedition in the Galapagos Islands and find short cacti and tall cacti. Which one or more
of the following would likely represent useful means of determining whether these represent two separate
species?
a) Observe the cacti to see if the same animals feed on the roots of both plants.
b) Observe the cacti to see if both plants flower about the same time.
c) Rub some of the leaves of each plant on your face and see if you break out in a rash.
d) Experiment to see if pollen from one type can fertilize the flower of the other.
e) (b) and (d)
12. Not all of the plant and animal species found in Ecuador live on the Galapagos Islands. This is true
because of which one or more of the following?
a) Not all species survived the journey from Ecuador to the Galapagos.
b) Not all species survived after reaching the Galapagos.
c) Not all species in Ecuador made the journey to the Galapagos.
d) Some species may have survived the journey to the Galapagos but failed to have offspring.
e) All of the above are true.
13. If polar bears migrated to the Galapagos and survived for hundreds of thousands of years, how would
their descendants on the Galapagos Islands be likely to differ from their northern cousins?
a) They would have more body fat.
b) They would be larger and have shorter appendages relative to body size.
c) They would be smaller and have longer appendages relative to body size.
Use the following information and the two illustrations above to answer the next 3 questions. A scientist
creates two electron acceptors that can strip electrons away from transport proteins in the electron transport
system found in thylakoid membranes. Compound A pulls the electron away from the first protein,
Compound B pulls the electron away from the last protein (right before Photosystem I, see figure). He adds
these compounds to a solution containing isolated functioning chloroplasts that contain no pigments other
than chlorophyll a and b.
14. Predict which of the following is most likely to occur in the A+B tube.
a) NADPH is produced.
b) ATP production is increased.
c) Water is split.
d) CO2 is produced.
e) Water is produced.
15. If only Compound A were added (A tube), you would correctly predict that the hydrogen gradient across
the thylakoid membrane would
a) greater than the control.
b) less than the control.
c) the same as the control.
16. Which of the following would you correctly predict if in the absence of either compound (Control tube),
the scientists shines only green light on the chloroplasts?
a) Water would be split faster
b) ATP production would continue at the same rate
c) NADPH production would increase
d) the rate of electron flow would increase
e) none of the above
17. Because brushbushes live in a dry climate, when they photosynthesize during the day their rate of
transpiration (all other things being equal) is which one or more of the following?
a) higher than a plant that lives in a humid tropical rainforest
b) higher than when the brushbushes are not photosynthesizing
c) lower than a plant that lives in a humid tropical rainforest
d) (a) and (b)
e) (b) and (c)
18. Wood is a product of trees. This material is made of complex compounds containing mainly the
elements carbon, hydrogen and oxygen. Given that the building blocks for wood originally came from the
Calvin cycle (light independent reaction of photosynthesis), what compounds from the external environment
provide these elements for the making of wood?
a) carbon dioxide and water
b) glucose and acetyl CoA
c) NADH and pyruvate
d) oxygen and lipids
e) proteins and fatty acids
19. Lichens are composed of algae and fungus that live together in dry environments in a mutually beneficial
relationship. The algae is beneficial to the fungus because it produces energy containing compounds (food)
that can be used by the fungus. Algae produce these compounds from photosynthesis the same way as
plants. What compound(s) from the algae is the fungus likely to be using for energy?
a) carbon dioxide and water
b) ADP
c) chocolate
d) sugars (such as glucose)
e) light
20. Use the graph of per cent of red light available as a function of depth on the following page to answer
this question. You find live Lily pads (a green plant) floating on top of a pond. You also find plants at the
bottom of the pond about 15 meters below the surface. (This is a very deep pond!) You collect samples of
each plant and bring each of them back to the laboratory. The next thing that you do is to grind them up.
You forgot to label each sample so you do not know which mush came from which plant. However, when
you examine the absorption spectra of the mush from each plant, you find that the slimiest mush does not
absorb red wavelengths of light. Which one or more of the following would be the best hypothesis based on
this finding?
a) These results do not provide any information to suggest which mush came from which plant.
b) The slimiest mush likely came from the Lilly pad.
c) The slimiest mush likely came from the plant found on the bottom.
d) The slimiest mush likely came from a plant that does not use photosynthesis.
e) that both (b) and (d) are true.
Use the following information to answer the next 12 questions. On the Creosote Islands, which are located
at the equator, there are 5 types of brushbushes. All the bushes are roughly the same height and thrive on the
islands that have lots of sunlight and no other similarly sized plants. All the plants are highly droughtresistant, but the plants and seeds rapidly shrivel if exposed to salt water. The plants are pollinated by bats
and produce seeds that are highly toxic and have little tufts that make them float in air for long distances.
Consuming the seeds leads to rapid convulsions. Each type of brushbush flowers in a different month and
has a slightly different moisture requirement (rainfall). The only similar type of brushbush in the world lives
about 500 Km away on the continent in an area with no bats. A beetle pollinates the continental species.
Bats can recognize plants by the sonar pattern returning from the different flower shapes while they are
echolocating. To determine whether the number of petals is heritable, the scientist looks to see if the
number of petals in parental plants and their offspring are correlated. The Creosote Islands are volcanic in
origin (similar to the Galapagos Islands) and the youngest is about 10 million years old. A scientist studying
the plants has published a paper concluding that the island plants are five species that resulted from adaptive
radiation.
Plant:
Island A
Island B
Island C
Island D
Island E
Continent
Minimum
rainfall
required
Maximum
Rainfall
tolerated
Breeds in
2 cm
3 cm
4 cm
4 cm
5 cm
5 cm
3 cm
4 cm
4.5 cm
5 cm
6 cm
8 cm
October
September
August
July
June
June
Flower shape
3 petals
4 petals
5 petals
6 petals
8 petals
7 petals
Length of
Pollinating
Bats tongue
Depth of
flower till
nectar pool
9 cm
11 cm
7 cm
5 cm
2 cm
-
9 cm
11 cm
7 cm
5 cm
2 cm
2 cm
21. Which data from the table best support the hypothesis that the plants are different species?
a) They breed at different times
b) They possess different numbers of petals
c) They have different water requirements
d) They are pollinated by bats
22. To test that the plants are different species, the best experiment would involve
a) removing the bats.
b) watering the plants.
c) removing nectar.
d) taking pollen from each type of plant and placing it on the flowers of all the other types.
e) removing petals from the plants to confuse the bats.
23. Which one of the following hypotheses for how the brushbush seeds arrived on the island is best
supported by the observations? The seeds
a) were deposited in bird feces.
b) were blown over by wind.
c) floated over on ocean currents.
d) were carried over by pollinating bats.
e) were carried on penguin feathers.
24. If you placed the seeds in saltwater, you would correctly predict that
a) the seeds would swell as water entered them.
b) the seeds would lose weight as salts left them.
c) the seeds would gain weight as water entered them.
d) the seeds would lose weight as water left them.
e) the seeds would remain unchanged.
25. Based on the data, what evidence suggests that adaptive radiation occurred on the islands?
a) plants are all very different with no obvious anatomical or ecological relationships
b) plants are all identical or almost so and use the same resource.
c) there is a pattern of similarity among the plants on the islands and a single relative on the
continent
d) all the plants reproduce using seeds
e) all the plants photosynthesize
26. Based on the data above, which of the following provides evidence for a coevolutionary relationship
based on the data above
a) breeding season and minimum water requirement
b) bats' tongue length and breeding season
c) minimum water requirement and maximum water requirement
d) bats' tongue length and water requirement
e) bats' tongue length, flower depth, and number of petals
27. Based on the data provided, which one or more of the following factors would you correctly hypothesize
led to adaptive radiation in the plants?
a) plants adapted to the islands with different amounts of rainfall
b) plants adapted to the islands with different amounts of sunlight
c) plants adapted to the islands with different numbers of insects
d) (a) or (b)
e) (a) or (c)
28. The scientist would have wanted to check for heritability of petal number, because
a) it determines for sure whether they are species
b) if natural selection is to lead to an adaptation, a trait must be heritable
c) he could then explain variation
d) he could examine the founder effect
29. Compared to the continental population, the first brushbushes on the island had a ______ variable
genetic make-up (range of characteristics)
a) more
b) less
c) the same
30. Brushbushes have toxic seeds, because
a) they need them to survive
b) they needed to evolve them to protect themselves against predators
c) those plants that had slightly toxic seeds were more likely to survive and reproduce
d) the presence of predators caused the plant's genes to mutate
e) they are a different species than those that dont.
31. If a bat were to eat the brushbush seeds and begin convulsing, its synapses would be affected in which
one or more of the following ways?
a) an action potential before the synapse, but no action potential after
b) an action potential before the synapse, and an action potential after
c) no action potential before the synapse, and no action potential after after
d) no action potential before the synapse, but an action potential after
e) could be (b) or (d) depending on how the toxin worked
32. Which way of working is consistent with the result of eating the brushbush seeds?
a) The toxin holds Na+ channels open.
b) The toxin holds K+ channels open.
c) The toxin blocks receptors for neurotransmitter.
d) The toxin blocks release of vesicles holding neurotransmitter.
e) The toxin blocks the active site of the enzyme responsible for breakdown of the neurotransmitter.
.
33. In some bacteria, photosynthesis involves recycling of the same electrons so that the electrons from the
reactive chlorophyll do not need to be replenished from water. From this, you would correctly predict that
these photosynthetic bacteria:
a) do not generate oxygen.
b) do not need CO2 to live.
c) do not use electron carriers.
d) are probably yellow in color.
e) Both (b) and (d).
34. In plant photosynthesis, the light dependent reactions occur in the thylakoid of the chloroplast. Where
do the light independent reactions occur?
a) the intermembrane space of the mitochondria
b) the mitochondrial matrix
c) the thylakoid of the chloroplast
d) the stroma of the chloroplast
e) the nucleus
Use the following information to answer the next 5 questions. You are going to do a science fair project on
photosynthesis. You are going to demonstrate the effects of light on the rate of photosynthesis. You ask a
friend of yours who works with plastics to build the experimental incubation chamber into which you will
place leaves and measure the rate of photosynthesis. You have decided that you will use spinach leaves as
your photosynthetic material.
35. Which of the following parameters can you use to measure the rate of photosynthesis?
a) Amount of carbon dioxide consumed
b) Amount of water produced
c) Amount of oxygen produced
d) Amount of oxygen consumed
e) (a) and (c)
36. You did not test your project before the day of the science fair (a fatal mistake!). You shine your light
on your spinach leaves and find that there is no measurable rate of photosynthesis. Based on this
observation, which one or more of the following is (are) the best hypothesis (es) to explain this?
a) Your friend's plastic absorbed most of the green wavelengths of light.
b) Your friend's plastic only allowed green wavelengths of light to pass through.
c) Your light source is producing large amounts of blue and red wavelengths of light.
d) Your light source is producing only large amounts of green wavelengths of light.
e) (b) and (d)
37. You shine your light directly on a group of balloons that are green, blue, yellow, red and purple. Only
the green balloon appears green and all of the other balloons appear black (or their own color). Which of the
following hypotheses best explains why your light source does not produce a measurable rate of
photosynthesis?
a) Your friend's plastic absorbed most of the green wavelengths of light.
b) Your friend's plastic only allowed green wavelengths of light to pass through.
c) Your light source is producing large amounts of blue and red wavelengths of light.
d) Your light source is producing only large amounts of green wavelengths of light.
e) HELP!
38. You find another light source at another project. You borrow the light source and shine it on your leaves
in the experimental chamber and find that there is a very high rate of photosynthesis. Which of the
following is the best hypothesis to explain this?
a) Your friend's plastic absorbed all of the wavelengths of light.
b) Your friend's plastic reflected blue and red wavelengths of light.
c) Your friend's plastic only allowed green wavelengths of light to pass through.
d) Your friend's plastic allowed plenty of red and blue wavelengths of light to pass through.
e) There is no carbon dioxide in the chamber.
39. At another project's table you notice that someone is looking at the effects of an ionophore on the rate of
photosynthesis. He explains to you that an ionophore punches holes in the thylakoid membrane allowing
protons (H+) to freely move across the thylakoid membrane. In addition to causing a reduced rate of
photosynthesis, this ionophore has a more direct effect resulting in which of the following?
a) increasing the amount of ATP made compared to the control
b) decreasing the amount of oxygen produced compared to the control
c) decreasing the amount of ATP made compared to the control
d) increasing the amount of FADH2 made compared to the control
e) decreasing the amount of FADH2 made compared to the control
40. ________ produced in the light dependent reactions provide energy to run ___________.
a) ATP and NADPH; Krebs cylce
b) ADP and FAD;
Krebs cycle
c) ATP and NADPH; Calvin cycle (light independent reactions)
d) ADP and NADP; Calvin cycle (light independent reactions)
e) electron carriers; ATP