Exam 2 Essays (50 points)
Please save a copy of this document and type your answers beneath each question. Keep
the present format. Resave and rename the file with your last name at the beginning of
the filename (i.e., Smith Exam 2 Essays), and submit it as an attachment to the dropbox.
What is the current population of the world? 1 Point
ANS: The current population of the world is 6.7 billion.
What is its current growth rate (expressed as a percentage)? 1 point
ANS: Its current growth rate is 1.3%
If a country has a growth rate of 1.7 %, how long will it take for its population to
double? (Must show calculation for credit.) 1 point
ANS: From the rule of 70, 70/1.7 = 41.18 (similar to 41 yrs), so It will take 41 yrs for its
population to double.
What spectacular biome (considered a complex zonation) is known as “islands of
biodiversity”? 1 point
List the top 3 areas of greatest
biodiversity. (Hint: Do NOT
give me “euphotic zone”, etc. Rather, they are types of aquatic habitat that your
text says has the most biodiversity.) 3 Points
ANS: Coastal wetlands, coral reefs, and ocean bottoms.
Name 6 things that you and others can do to help sustain
Be specific to this issue. 3 points
Avoid using plastic bags, bringing our own shopping to supermarket. Do not waste
papers, and use both sides of them. Save up more trees instead of cutting them, because
they take so much longer to grow than we cut them off. Plant more trees around our
environment. Do not drive cars if not necessary, because pollutants can affect our
environment and the biodiversity. Separate our trash into recycle bin, and use recycle
List ALL the primary and secondary causes of depletion and extinction of wild
species according to your textbook. 3 Points
ANS: Rapid population growth, rising resource use, no environmental accounting and
poverty are the primary causes of depletion and extinction of wild species. The secondary
causes are habitat loss, habitat degradation and fragmentation, pollution, introducing
nonnative species that affects the native species, change of climate, over fishing, lack of
predator and pest control, too much commercial hunting and poaching and sale of exotic
pets and decorative plants.