1.  The tropics are consistently warmer than other regions of the earth.  Why?
Since the tropics are located at the equator where the sun's rays (energy) directly strike the earth, the tropics absorb the most energy from the sun and are, therefore, consistently warmer than other regions.  In addition, because the equator does not change its distance from the sun on a seasonal basis, the tropics are warm year-round unlike regions farther north or south.

2.  The Gulf Stream makes California
a.  warmer                b.  colder                   c. no different because it has no effect on that region
c.  no different because it has no effect on that region
The Gulf Stream is the current of warm water that comes out of the tropics, travels along the EAST coast of the U.S., and eventually makes its way across the Atlantic Ocean and affects the climate of England, Scotland, Wales, Ireland, and Iceland.  Since it is found on the EAST coast, and California is on the WEST coast, it has no effect on that region.
 

3.  Which biome is characterized by having a poor humus layer?
a.  desert           b.  broadleaf deciduous forest             c.  broadleaf evergreen forest                d.  both a and c
d.  both a and c
Both deserts and broadleaf evergreen forests (tropical rainforests) have a very thin humus layer.  Very thin=poor in terms of plant growth
 

4.  Elephants knock over trees to forage on the leaves of trees in their native habitat.  What type of community level species interaction would the elephant have on the bird species that nest in that tree? (hint:  the elephant is not negatively affected by the presence of the bird).
The elephant and bird have an indirect interaction since the birds are using the trees for nesting and the elephants are using the trees for food; technically, this is not competition because they are not using the same resource in the same way nor is the elephant affected negatively by the bird's use of the tree for a site for its nest (species that compete use the same resource which causes a negative effect on BOTH species since the use of the resource by one precludes the use of it by the other).  They are not having a direct interaction because the two species are not directly affecting the distribution of one another through predation, etc.
 

5.  Feeding levels in a community are also referred to as        ?         levels.
Trophic levels

6.  The competitive exclusion principle states that no two species living in the same area can have the exact same     ?
Niche

7.  Suppose that a tornado rips through the soybean field located next to the chancellorís residence.  What type of successional community would be the first to develop after the tornado is gone if the tornado only removed the living material above ground; it did not disturb the soil?
a.  primary                     b.  secondary                 c.  climax               d.  both b and c                        e.  none of the above
b. secondary
Since the tornado only removes the living material above the ground, organisms are still found in the soils.  Primary succession only occurs when no living organisms are found in the area.  Any time there is a disturbance where some species are removed, the climax community is lost and has to go through some succession again (usually secondary succession).
 
 

8.  Suppose you have to examine an ecosystem to determine whether it will be self-sustaining with the only input to the ecosystem being energy from the sun.  All other energy sources will be contained within a biodome.  Your ecosystem will have the following percentages of total number of individuals:  primary producers 35%; primary consumers 35%; secondary consumers 20%; and tertiary consumers 10%.  Using your knowledge about ecological pyrimids and energy flow, will this ecosystem be self-sustaining?  Why?
Anytime you see a question like this, you may want to set up your ecological pyramid to determine the relative size of each trophic level.
In this ecosystem, there are too few primary producers to support the same number of primary consumers (which are exactly equal to the number of primary producers, but since energy is LOST at each level, these trophic levels should be SMALLER than the primary producers).
 
 

9.  What type of population growth is the global human population experiencing?
Exponential population growth

10.  You want to determine the size of the white-tailed deer population in three years in an area where the current population is experiencing exponential growth.  Assuming that the rate of growth will remain the same each year; suppose you begin with a population of 100 individuals, at the end of one year 1000 individuals were born/hatched, and 300 died.  Calculate the per capita birth rate, the per capita death rate, the net reproductive rate per individual per year, and the number of individuals that will be in the population at the end of three years.  Calculate and answer on the back (show all calculations).

pcb = 1000 / 100 = 10
pcd = 300 / 100 = 7

r = 10 - 7 = 3

year 1 = 100 x 7 = 700 + 100 =  800
year 2 =  800 x 7 = 5600  + 800  = 6400
year 3 = 6400 x 7 =  44,800 + 6400 = 51,200

The number of deer in the population at the end of 3 years of exponential growth would be 51,200 individuals.