Download iGCSE Biology Section 4 lesson 1

IGCSE BIOLOGY
SECTION 4 LESSON 1
Content
Section 4
Ecology and
the
Environment
a) The organism in the
environment
b) Feeding relationships
c) Cycles within ecosystems
d) Human influences on the
environment
Content
Lesson 1
a) The organism
in the
environment
a) The organism in the
environment
4.1 understand the terms population,
community, habitat and ecosystem
4.2 explain how quadrats can be used to
estimate the population size of an
organism in two different areas
4.3 explain how quadrats can be used to
sample the distribution of organisms in
their habitats.
Population – a
group of
organisms of one
species living in
the same place at
the same time
The
organism in
the
environment
Population – a
group of
organisms of one
species living in
the same place at
the same time
The
organism in
the
environment
Community - a
group of actually
or potentially
interacting
species living in
the same place
Population – a
group of
organisms of one
species living in
the same place at
the same time
The
organism in
the
environment
Habitat – place
where an
organism or a
community of
organisms lives
Community - a
group of actually
or potentially
interacting
species living in
the same place
Population – a
group of
organisms of one
species living in
the same place at
the same time
Ecosystem –
network of
interactions
among
organisms, and
with their
environment
The
organism in
the
environment
Habitat – place
where an
organism or a
community of
organisms lives
Community - a
group of actually
or potentially
interacting
species living in
the same place
Ecological sampling techniques
Ecological sampling techniques
Quadrat
Ecological sampling techniques
Quadrat
Sweep net
Ecological sampling techniques
Quadrat
Sweep net
Beating tray
1 metre
0.5 m
Using Quadrats
0.25 m
0.5 m
1 metre
0.25 m
Using Quadrats
10 metres
Using Quadrats
10 metres
TRANSECT
Using Quadrats
10 metres
TRANSECT
350 METRES
Using Quadrats
500 METRES
350 METRES
Using Quadrats
500 METRES
Quadrats
distributed
randomly using
random number
tables
350 METRES
Using Quadrats
500 METRES
Quadrats
distributed
randomly using
random number
tables
Using Quadrats
Using Quadrats
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Are daisies less common in areas that
are frequently trampled?
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Are daisies less common in areas that
are frequently trampled?
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Are daisies less common in areas that
are frequently trampled?
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Are daisies less common in areas that
are frequently trampled?
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Are daisies less common in areas that
are frequently trampled?
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Are daisies less common in areas that
are frequently trampled?
Count the number of daisies in
each quadrat
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
35
6
16
29
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Number of daisies
35
6
16
Estimate the
population size
of an organism
in different
areas.
29
Sample the
distribution of
organisms in
their habitats
40
20
0
0
1
2
3
4
5
Distance along transect (metres)
6
7
Using Quadrats
Number of daisies
35
6
16
Estimate the
population size
of an organism
in different
areas.
29
Sample the
distribution of
organisms in
their habitats
40
20
0
0
1
2
3
4
5
Distance along transect (metres)
6
7
Using Quadrats
Number of daisies
35
6
16
Estimate the
population size
of an organism
in different
areas.
29
Sample the
distribution of
organisms in
their habitats
40
20
0
0
1
2
3
4
5
Distance along transect (metres)
6
7
Using Quadrats
Daisies seem to grow
less well in trampled
areas
Number of daisies
35
6
16
Estimate the
population size
of an organism
in different
areas.
29
Sample the
distribution of
organisms in
their habitats
40
20
0
0
1
2
3
4
5
Distance along transect (metres)
6
7
Using Quadrats
Broad-leaved plantain.
Plantago major
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Broad-leaved plantain.
Plantago major
What is the plantain
population in this area of
coastal grassland?
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Grassland area
= 12 x 12 m
= 144 m2
Using Quadrats
Quadrat used =
1m2
Number of
random quadrats
thrown = 20
Total area
sampled = 20m2
Grassland area
= 12 x 12 m
= 144 m2
Using Quadrats
Quadrat used =
1m2
Number of
random quadrats
thrown = 20
Total area
sampled = 20m2
Grassland area
= 12 x 12 m
= 144 m2
Using Quadrats
Quadrat
Number of plantains
1
19
2
5
3
21
4
17
5
33
6
29
7
4
8
16
9
23
10
6
11
17
12
19
13
12
14
37
15
4
16
16
17
15
18
38
19
33
20
27
Using Quadrats
Quadrat
Number of plantains
1
19
2
5
3
21
4
17
5
33
6
29
7
4
8
16
9
23
10
6
11
17
12
19
13
12
391 / 20
14
37
15
4
= 19.55
16
16
17
15
18
38
19
33
20
27
Total number of
plantains = 391
Average number of
plantains per
quadrat (1m2) =
Using Quadrats
Quadrat
Number of plantains
1
19
2
5
3
21
4
17
5
33
6
29
7
4
8
16
9
23
10
6
11
17
12
19
13
12
391 / 20
14
37
15
4
= 19.55
16
16
17
15
18
38
19
33
20
27
Total number of
plantains = 391
Average number of
plantains per
quadrat (1m2) =
Total number
of plantains in
the grassland
area =
144 X 19.55
= 2,815
Using Quadrats
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
Using Quadrats
Estimate the
population size
of an organism
in different
areas.
Sample the
distribution of
organisms in
their habitats
End of Section 4 Lesson 1
In this lesson we have covered:
• the terms population, community, habitat and
ecosystem
• quadrats, and how they can be used to estimate
the population of a species, and also the
distribution of a species.