Biology 12

Unit 5 Review • MHR 543

MAKING CONNECTIONS

44.Many ecologists point out that in addition to
the need to conserve ecosystems because they
contain resources or goods(food, water, and
various mineral elements, for example), we
also need to recognize that ecosystems perform
indispensable services. What do you think this
means? Describe some of these services. Are
there other equally effective ways to obtain these
services? Or do you think this is another good
reason to conserve a diversity of ecosystems?
Give reasons for your answers.

45.Do you think the AIDS epidemic will have as
much impact on the world as the bubonic
plague epidemic that struck in the fourteenth
century? Why or why not? The genetic structure
of the human immunodeficiency virus (HIV)
that causes AIDS changes frequently. What
impact might this have on the virus’s ability
to affect human population growth?

46.As habitats around the world are lost, many
species go extinct before we have even
discovered them. What advantages are
provided by high levels of species diversity,
genetic diversity, and ecosystem diversity? In
other words, what is the value of biodiversity?
How might ecologists, or the citizens of countries
with high levels of diversity that are rapidly
being lost (such as countries in Central America,

for example), use this “value” to preserve

habitats and species? Answer this question as

an essay, perhaps focussing on one country or

region of the world.

47.Farmers in West Africa first began to cut and

burn forests to increase the availability of

arable land about 3000 years ago. Recently,

scientists have suggested that the parasite that

causes the disease malaria first evolved in West

Africa at around the same time. If this is true,

what have been the long-term effects of this

farming practice? To answer this, find out more

about malaria, including its cause and effect on

individuals. In what areas of the world does

malaria currently occur, and how widespread

is it? What methods are used to treat and

control it, and what are the environmental

effects of these methods?

As you continue to prepare for the Biology Course

Challenge, consider the environmental issues presented

in Chapter 15 and their effects on the carrying capacity

of Earth. Consider selecting one of these issues, and its

effects on different species and their populations, as the

topic for your Challenge.

COURSE CHALLENGE

make a three-dimensional model of your city,

or draw maps and diagrams to illustrate your

plan. This should be accompanied by a

report describing how your city will achieve

sustainable resource use.

42.Research the impact of coffee growing on a
country that exports this crop to Canada. Does
the country achieve a net profit or a net loss as
a result of growing coffee? Are environmental
costs included in these calculations? Does this
country produce any shade-grown coffee? What
are the advantages and disadvantages of using
this method to grow coffee beans? Design a
pamphlet or poster that might serve as part of a
publicity campaign to educate people about the
environmental impact of coffee plantations.
Alternatively, write a letter to the CEO or
president of a company that imports or sells
coffee, expressing your point of view.

43.Some introduced species are useful to humans
(for example, most crops) and are relatively
harmless to the environment. But others, like

the zebra mussel, are referred to as invasive.

Invasive species tend to grow over-abundantly,

taking over ecosystems and disrupting normal

ecological processes. Identify 20 to 50 species

of plants, animals, or other organisms growing

in the area of your school. Each member of the

class should become an expert on one of the

different species. Determine whether your

species is native or introduced, and learn as

much as you can about its biology. If your

species is native, find out whether it is affected

by (or at risk of being affected by) introduced

species. If your species is introduced, find out

when and how it was introduced and whether

it is harmless or invasive. What impact has it

had on other species? What methods, if any,

are being used to control the spread of this

species? Are they successful? Hold a classroom

conference on the effects of introduced species.

Each student should make a brief presentation

on his or her species, describing what is known

about the species and suggesting areas for

further study.