Welcome to Biology
Concepts in scientific method 1Match the word with the correct example
• Observation• Inference• Generalisation• Theory• Law
• For every reaction there is an equal and opposite reaction.
• The leaf is green.• All living things contain cells. All
cells come from other cells.• The leaf must contain
chlorophyll.• All plant cells contain
chloroplasts.
Concepts in scientific method 1Match the word with the correct example
• Observation• Inference• Generalisation• Theory• Law
• For every reaction there is an equal and opposite reaction.
• The leaf is green.• All living things contain cells. All
cells come from other cells.• The leaf must contain
chlorophyll.• All plant cells contain
chloroplasts.
Concepts in scientific method 2
Identify the:• Hypothesis
• Independent variable
• Dependent variable
• Control
• Variables that need to be controlled
Question: Which type of insect repellent is the most effective?Experiment: Spray sticky strips with different repellents. Leave
outside for several hours. Count the number of insects that are stuck to each strip.
Concepts in scientific method 2
Identify the:• Hypothesis Brand X will repel less/more insects than Brand Y
• Independent variable brand/type of repellent
• Dependent variable insects stuck to strip
• Control sticky strip with no repellent
• Variables that need to be controlled – same size, shape & colour of strip, same amount of repellent, same temperature, humidity, location of strip
Question: Which type of insect repellent is the most effective?Experiment: Spray sticky strips with different repellents. Leave
outside for several hours. Count the number of insects that are stuck to each strip.
Dealing with data
Collecting, displaying and analysing data
Tables
• Key points:
Independent variable
Dependent variable(s)
Graphs - Key points
Title
Dependent variable 3 Grid
goes on the
Vertical axis (Y) 2 Plotted points or line or curve
Use an even scale 1
and include units
0
1 2 3 4 5
Independent variable goes on the Horizontal axis (X)
Use an even scale and include units
Graph should take up 1/2 – 2/3 of the page. Allow enough space to extrapolate the next point or two.
Types of graphs
growth of a plant
0
0.5
1
1.5
2
2.5
3
1 2 3 4 5 6 7
day
hei
gh
t (c
m)
height (cm)
types of trees in the school
0
2
4
6
8
10
12
14
16
18
bank
sia
bottl
ebru
sh
euca
lypt
gras
s tre
e
wattle
type of tree
nu
mb
er
numbers
fruit production in tomatoes
0
2
4
6
8
10
12
14
0 - 0.5 0.6 - 1.0 1.1 - 1.5 1.6 - 2.0
weight of fruit harvested
nu
mb
er o
f p
lan
ts
number
height and weight
0
10
20
30
40
50
60
70
0 0.5 1 1.5 2
height (m)
wei
gh
t (k
g)
Line graphsgrowth of a plant
0
0.5
1
1.5
2
2.5
3
1 2 3 4 5 6 7
day
hei
gh
t (c
m)
height (cm)
• used to plot continuous data• used to look for relationships where one affects
the other
Column or Bar graphs
• used to plot discontinuous data (categories)• used to show how many in each category
types of trees in the school
0
2
4
6
8
10
12
14
16
18
bank
sia
bottl
ebru
sh
euca
lypt
gras
s tre
e
wattle
type of tree
nu
mb
er
numbers
Histogramsfruit production in tomatoes
0
2
4
6
8
10
12
14
0 - 0.5 0.6 - 1.0 1.1 - 1.5 1.6 - 2.0
weight of fruit harvested
nu
mb
er o
f p
lan
ts
number
• used for grouped data
Scatter graphs
• used for look for relationships
height and weight
0
10
20
30
40
50
60
70
0 0.5 1 1.5 2
height (m)
wei
gh
t (k
g)
Day Height (cm)
1 64
2 68
5 92
7 110
10 134
12 140
14 152
17 160
18 162
20 168
Growth of a plant
Growth of plant
0
20
40
60
80
100
120
140
160
180
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Day
Hei
gh
t (c
m)
Height (cm)
Birds seen at school
Galah 4Raven 7Pigeon 6Wattle bird 3Willie wagtail 1
Birds seen at school
0
1
2
3
4
5
6
7
8
Galah Raven Pigeon Wattle bird Willie wagtail
Type of bird
Nu
mb
er o
f b
ird
Height (m) Number of
students
139 140 – 149
2 1
150 - 159 2
160 - 169 3
170 - 179 1
180 - 189 1
190 - 199 1
200 0
Number of students of different heights
0
0.5
1
1.5
2
2.5
3
3.5
<139 140– 149
150 - 159 160 - 169 170 - 179 180 - 189 190 - 199 >200
Height (cm)
Nu
mb
er o
f st
ud
ents
Number of students
Student Height (m)
Leg length
(m)
10 steps (m)
1 1.64 0.97 5.9
2 1.67 1.05 7.45
3 1.54 0.93 6.1
4 1.49 0.91 6.78
5 1.83 1.02 6.58
6 1.76 1.0 8.0
7 1.53 0.87 6.5
8 1.91 1.07 10.1
9 1.68 0.95 6.45
10 1.44 0.79 5.7
height vs 10 steps
0
24
6
810
12
0 0.5 1 1.5 2 2.5
height
10 s
tep
s
10 steps (m)
leg length vs 10 steps
0
2
4
6
8
10
12
0 0.2 0.4 0.6 0.8 1 1.2
leg length (m)
10 s
tep
s (m
)
10 steps (m)
