Integrated Programme
Sec 2 SBGE, LSS Biology Module
Name: ______________________( ) Class: _____Date: __________
Introduction to Ecology
Worksheet 2
I) In 1975, a massive leak from a military fuel storage facility released
about 80,000 gallons of kerosine-based jet fuel in Hanahan, South
Carolina, a quiet suburb of Charleston. Immediate and extensive
recovery measures managed to contain the spill, but could not prevent
some fuel from soaking into the permeable sandy soil and reaching the
underlying water table. Soon, ground water was leaching such toxic
chemicals as benzene from the fuel-saturated soils and carrying them
toward a nearby residential area.
By 1985, contamination had reached the residential area, and the
facility was faced with a serious environmental problem. Removing the
contaminated soils was technically impractical, and removing
contaminated ground water did not address the source of the
contaminants. How could contaminated ground water be kept from
seeping toward the residential area in the future?
One possible solution was a new technology called bioremediation.
Studies by the U.S. Geological Survey (USGS) had shown that
microorganisms naturally present in the soils were actively consuming
fuel-derived toxic compounds and transforming them into harmless
carbon dioxide. Furthermore, these studies had shown that the rate of
these biotransformations could be greatly increased by the addition of
nutrients. By "stimulating" the natural microbial community through
nutrient addition, it was theoretically possible to increase rates of
biodegradation and thereby shield the residential area from further
contamination.
a) Name the types of pollution caused by the fuel leakage.
land and water pollution
[2]
b)From Paragraph 1, line 6, describe what you understand by the term
“Water Table”.
[1]
Water Table refers to ground water – source of drinking water
c) From Paragraph 2, what do you think the sentence “the facility was
faced with a serious environmental problem” was trying to tell you?
[2]
The area was having a serious pollution. The land was polluted and so
was the water being poisoned and this pollution is reaching where the
people are living.
d) From Paragraph 3, explain what you understand by the word
“Bioremediation”.
[1]
Use of micro-organism to break down the toxic substances to harmless
substances
e) From Paragraph 3, how can the microbial community be
“stimulated”?
[1]
Adding of nutrients to encourage growth of micro-organism
f) How does “stimulation” helps in “biotransformation”?
[1]
It speeds up the process of biodegradation of the toxic substances to
harmless substances
II) Species diversity Index
The formula for species diversity index is as follows:
D=
N(N-1)
n(n-1)
N – total number of all organisms in the community
n - number of organisms of a particular species
 - sum of
High diversity index
–
-
Low diversity index
well-established
stable community
many successful species
less well-established
less stable community
dominated by few species
Compare the 3 areas in terms of diversity with the data given below:
[15]
Population of
Species
A
B
C
D
E
Area 1 ,
Area 1
Area 2
Area 3
90
10
75
20
60
80
30
10
3
1
20
25
23
24
22
N
= 90+10+75+20+60
= 255
N(N-1)
= 64770
For Population A, n(n-1)
=
=
=
=
=
=
For Population B, n(n-1)
For Population C, n(n-1)
90(90-1)
8010
10(10-1)
90
75(75-1)
5550
For Population D, n(n-1)
For Population E, n(n-1)
Area 2 ,
N
N(N-1)
For Population A, n(n-1)
For Population B, n(n-1)
For Population C, n(n-1)
For Population D, n(n-1)
For Population E, n(n-1)
Area 3 ,
N
N(N-1)
For Population A, n(n-1)
For Population B, n(n-1)
For Population C, n(n-1)
For Population D, n(n-1)
For Population E, n(n-1)
=
=
=
=
20(20-1)
380
60(60-1)
3540
= 80+30+ 10+ 3 +1
=124
= 15252
= 80(80-1)
= 6320
= 30(30-1)
= 870
= 10(10-1)
= 90
= 3(3-1)
=6
= 1(1-1)
=0
= 20+25+23+24+22
= 114
= 12882
=
=
=
=
=
=
=
=
=
=
20(20-1)
380
25(25-1)
600
23(23-1)
506
24(24-1)
552
22(22-1)
462
Area 1: D1
=
=
=
Area 2: D2
=
=
=
Area 3: D3
=
=
N(N-1)
n(n-1)
64770
17 570
3.7
N(N-1)
n(n-1)
15252
7286
2.1
12882
2500
5.2
The species diversity index of Area 3 is the highest. The area is the
most established. The 5 species are equally successful
The species diversity index of Area 1 is the second highest. The area
is quite well established and dominated by Species A & C. Area 2 is
the least well established and dominated by Species A
III) The newspaper article was written by the environmental
correspondent of a newspaper. It mixes scientific facts with
emotional or sensational phrases beginning with the banner
headline. Read the article and answer the following questions.
1. The rainforest is described as Earth’s global lungs. Explain this
term.
[2]
The rainforest has a great number of species. They can take in
oxygen for photosynthesis and produce oxygen for the Earth.
2. Explain why soil erosion takes place when the rainforest is cleared.
[2]
Clearing of rainforest means that the rain will have direct impact on
the soil as the canopy cover is no longer around [1]. The roots of the
trees that help hold the soil in are also gone and hence soil erosion can
occur[1].
3. The article uses the term biodiversity. Explain the point being
made with reference to the article and also the term used.
Biodiversity means the variety of organisms, such as plants,
mammals, insects, reptiles and birds; this biodiversity is damaged by
the fires.
4. The article is written by a journalist rather than an academic
scientist. Find three phrases from the article which indicate this
and explain why they might have been used.
“The very thing which is ideal for mopping up the excess carbon
dioxide in the atmosphere is itself being burnt”
“The forest is also a kind of global lung, because as it soaks up carbon
dioxide, it releases carbon dioxide”
“The cattle farmers graze their herds to make hamburgers”
Phrases used are metaphoric, to allow readers to understand the
situation by comparing to common activities/phrases. They are also
used to sensationalise the situation and create a greater concern for it.