BIO 209W Exam 1 with100% correct
answers
Describe the 3 types of natural selection. Select and trait different that body size and create
figures to illustrate these concepts. - correct answer 1. stabilizing (most egg size produced at
mean value) 2. directional 3. disruptive (finches with medium size beaks are rare so the two
other extremes are favored)
What environmental changes were associated with the change in beak size? - correct
answer changes in seed size for feeding. example of directional selection
Describe 4 traits of the marine iguana that represent adaptations to the habitat in the
Galapagos. Please include association of the trait to an ecological function. - correct answer
Soapberry Bug: What kind of natural selection process this example represents? - correct
answer example of directional selection, Soapberry bugs use their slender beaks to pierce
the walls of the fruits of their host plants. To allow the bug to feed on the seeds within the
fruit, the beak must be long enough to reach from the exterior of the fruit to the seeds. The
distance from the outside of the fruit wall to the seeds varies widely among potential host
species. Thus, beak length should be under strong selection for appropriate length.
Explain the differences between the exotic and native soapberry fruit in Florida and South
Central - correct answer -The soapberry tree, Sapindus saponaria v. drummondii, in the
south central region of the United States; the serjania vine, Serjania brachycarpa, in
southern Texas; and the balloon vine, Cardiospermum corindum, in southern Florida.
-In Florida the fruit of the native host plant C. corindum has a much larger radius than the
fruit of the introduced K. elegans (11.92 mm versus 2.82 mm).
-In south central FL the fruit of the native S. saponaria has a smaller radius (6.05 mm) than
the fruits of the introduced K. paniculata (7.09 mm) and C. halicacabum (8.54 mm).
Explain how the beak size of the population of SBB that shifted to consume the exotic
species would change due to natural selection in Florida and South Central - correct answer
Carroll and Boyd reasoned that if beak length was under natural selection to match the
radius of host plant fruits, bugs shifting to the introduced plants in Florida should be selected
for reduced beak length, while those shifting to introduced hosts in the south central United
States should be selected for longer beaks.
Describe the differences between the Polar Easterlies and Westerlies winds - correct answer
-Polar easterlies are dry, cold prevailing winds that blow from the east. They emanate from
, BIO 209W Exam 1 with100% correct
answers
the polar highs, areas of high pressure around the North and South Poles. Polar easterlies
flow to low-pressure areas in sub-polar regions. Westerlies are prevailing winds that blow
from the west at midlatitudes.
-Someone studying winds within the temperate belt between 30° and 60° latitude would
observe that winds blow mainly from the west. These are the westerlies of temperate
latitudes. At high latitudes, our observer would find that the predominant wind direction is
from the east. These are the polar easterlies.
In class we discuss movement of air along the three cells of atmospheric circulation that are
related to the location of biomes from the Equator to the temperate zones.
Using a diagram(s) and text, show why tropical rain forests tend to be near the equator and
deserts near 30°latitude. - correct answer at the equator moist air rises, air cools as it rises,
then it can't hold moisture so it causes it to rain. once it reaches a certain point irt spreads
north and south and cools further. moist warm air and rain area typically occurs at 30-60
degrees latitude. Dry absorbing air absorbs moisture forming deserts typically located right
above tropics
On the last page of this document, I have included a climate diagram from each biome. On
the exam, I will give you one of these and ask you to tell me which biome it most likely
represents, and to justify your answer, i.e., tell me what information led you to your
conclusion. Note: I will omit the geographic location on the diagram I use for the exam. -
correct answer memorize diagrams/write out
English and European languages have terms for four seasons (summer, spring, autumn/fall,
winter). These words summarize much of the annual climatic variation at midlatitudes in
temperate regions.
Are these four seasons useful for summarizing annual climatic changes across the rest of
the globe? - correct answer I would say yes because many biomes experience the four
seasons which are classified by different amounts of precipitation and temperature variation
How many seasons would you propose for tropical dry forests and tropical savannas? -
correct answer -The climate of tropical dry forests is more seasonal than that of tropical rain
forests. The three climate diagrams shown in figure 2.14, for example, show a dry season
lasting for 6 to 7 months, followed by a season of abundant rainfall, lasting 5 to 6 months.
-As in the tropical dry forest, life on the savanna cycles to the rhythms of alternating dry and
wet seasons (see fig. 2.17). Here, however, seasonal drought combines with another
important physical factor, fire.
answers
Describe the 3 types of natural selection. Select and trait different that body size and create
figures to illustrate these concepts. - correct answer 1. stabilizing (most egg size produced at
mean value) 2. directional 3. disruptive (finches with medium size beaks are rare so the two
other extremes are favored)
What environmental changes were associated with the change in beak size? - correct
answer changes in seed size for feeding. example of directional selection
Describe 4 traits of the marine iguana that represent adaptations to the habitat in the
Galapagos. Please include association of the trait to an ecological function. - correct answer
Soapberry Bug: What kind of natural selection process this example represents? - correct
answer example of directional selection, Soapberry bugs use their slender beaks to pierce
the walls of the fruits of their host plants. To allow the bug to feed on the seeds within the
fruit, the beak must be long enough to reach from the exterior of the fruit to the seeds. The
distance from the outside of the fruit wall to the seeds varies widely among potential host
species. Thus, beak length should be under strong selection for appropriate length.
Explain the differences between the exotic and native soapberry fruit in Florida and South
Central - correct answer -The soapberry tree, Sapindus saponaria v. drummondii, in the
south central region of the United States; the serjania vine, Serjania brachycarpa, in
southern Texas; and the balloon vine, Cardiospermum corindum, in southern Florida.
-In Florida the fruit of the native host plant C. corindum has a much larger radius than the
fruit of the introduced K. elegans (11.92 mm versus 2.82 mm).
-In south central FL the fruit of the native S. saponaria has a smaller radius (6.05 mm) than
the fruits of the introduced K. paniculata (7.09 mm) and C. halicacabum (8.54 mm).
Explain how the beak size of the population of SBB that shifted to consume the exotic
species would change due to natural selection in Florida and South Central - correct answer
Carroll and Boyd reasoned that if beak length was under natural selection to match the
radius of host plant fruits, bugs shifting to the introduced plants in Florida should be selected
for reduced beak length, while those shifting to introduced hosts in the south central United
States should be selected for longer beaks.
Describe the differences between the Polar Easterlies and Westerlies winds - correct answer
-Polar easterlies are dry, cold prevailing winds that blow from the east. They emanate from
, BIO 209W Exam 1 with100% correct
answers
the polar highs, areas of high pressure around the North and South Poles. Polar easterlies
flow to low-pressure areas in sub-polar regions. Westerlies are prevailing winds that blow
from the west at midlatitudes.
-Someone studying winds within the temperate belt between 30° and 60° latitude would
observe that winds blow mainly from the west. These are the westerlies of temperate
latitudes. At high latitudes, our observer would find that the predominant wind direction is
from the east. These are the polar easterlies.
In class we discuss movement of air along the three cells of atmospheric circulation that are
related to the location of biomes from the Equator to the temperate zones.
Using a diagram(s) and text, show why tropical rain forests tend to be near the equator and
deserts near 30°latitude. - correct answer at the equator moist air rises, air cools as it rises,
then it can't hold moisture so it causes it to rain. once it reaches a certain point irt spreads
north and south and cools further. moist warm air and rain area typically occurs at 30-60
degrees latitude. Dry absorbing air absorbs moisture forming deserts typically located right
above tropics
On the last page of this document, I have included a climate diagram from each biome. On
the exam, I will give you one of these and ask you to tell me which biome it most likely
represents, and to justify your answer, i.e., tell me what information led you to your
conclusion. Note: I will omit the geographic location on the diagram I use for the exam. -
correct answer memorize diagrams/write out
English and European languages have terms for four seasons (summer, spring, autumn/fall,
winter). These words summarize much of the annual climatic variation at midlatitudes in
temperate regions.
Are these four seasons useful for summarizing annual climatic changes across the rest of
the globe? - correct answer I would say yes because many biomes experience the four
seasons which are classified by different amounts of precipitation and temperature variation
How many seasons would you propose for tropical dry forests and tropical savannas? -
correct answer -The climate of tropical dry forests is more seasonal than that of tropical rain
forests. The three climate diagrams shown in figure 2.14, for example, show a dry season
lasting for 6 to 7 months, followed by a season of abundant rainfall, lasting 5 to 6 months.
-As in the tropical dry forest, life on the savanna cycles to the rhythms of alternating dry and
wet seasons (see fig. 2.17). Here, however, seasonal drought combines with another
important physical factor, fire.
