True statement: Science
creates knowledge.
1. Making observations
2. Explaining the reasons for
those observations
What is a hypothesis?
Definition: A reserved explanation for events that have
been observed.
Prediction: A statement that claims an event will
happen again.
Hypothesis: The plant will produce more oxygen when the
temperature increased because the chemical reaction
photosynthesis will increase in speed. This reaction
produces oxygen as a waste product, as the temperature
increases therefore the amount of oxygen will also increase.
However, if the temperature increases beyond 45 degrees
Celsius then less oxygen will be collected as the reaction
begins to slow down. It slows down because the enzymes
that drive the chemical reaction photosynthesis have
denatured.
Prediction: As the temperature increases more oxygen will
be released up to a point. When the temperature gets too
high the oxygen levels will start to decrease.
Cells: route through the topic
Cell theory
Unicellular organisms
Sizes in perspective
Magnification
Emergent properties
Cell differentiation
Stem cells
Prokaryotes;E.coli, structure and fission
Eukaryotes: Liver cell
Micrographs of liver cells
Comparison of eukaryotes and prokaryotes
Comparison of plant and animal cells
Two roles of extrcellular components – cell wall, glycoproteins
Membranes
Transport
Mitosis
The Cell…..a brief history
• 1663: First cell
documented
• 1833 Brown
Schleiden and Schwann 1838
Discussed their observations of plants and
animal cells
• 1858, Rudolf Virchow
concluded that all cells come from preexisting cells thus completing the modern
theory.
"there is one universal principle
of development for the
elementary parts, of organisms,
however different, and this
principle is the formation of cells,"
Schwann: 1839
Cell Theory
1. All known living things are made up of cells.
2. The cell is structural & functional unit of all
living things.
3. All cells come from pre-existing cells by
division.
4. Cells contains hereditary information which is
passed from cell to cell during cell division.
What is a theory?
Pieces of evidence from observation and
facts which are synthesized into a
coherent whole
What is a system
A group of parts that come together. Take the
following materials….what could you make
with this?
•
•
•
a small metal cup, about the size of a walnut.
a glass bowl, in the shape of a small balloon.
a length of tungsten wire, pinched up into a
small coil.
What is an emergent property
Any function performed by a system that is not the result
of just a single part of that system but the result of all the
interacting parts is called and emergent property.
The light bulb is the result of the combination of all 3 parts.
The system is Irreducible.
Reading a book individual word at a time does not give
the story.
Task
Explain why a human being is a system
with emergent properties.
Emergent properties in Biology: The development of
complex systems.
The functions of Life
All living things do Mrs Gren regardless of
their size.
Scanning Electron Micrograph
Scanning Electron Micrograph
Dentist Drill
Scanning Electron Micrograph
Scanning Electron Micrograph
Porcupine Quill
Scanning Electron Micrograph
Scanning Electron Micrograph
Staple
Scanning Electron Micrograph
Scanning Electron Micrograph
Toilet Paper
Scanning Electron Micrograph
Scanning Electron Micrograph
Velcro
Scanning Electron Micrograph
Scanning Electron Micrograph
Black Widow Spider Claw
Scanning Electron Micrograph
Scanning Electron Micrograph
Mascara Brush
Scanning Electron Micrograph
Scanning Electron Micrograph
Hypodermic Needle
Transmission Electron
Micrograph
Transmission Electron
Micrograph
(a) 1 metre =________ millimetres
(b) 1 mm = ________ microns
(c) 1 µm =
________ nanometres
(d) 1 metre =________ nm
(e) 1 mm =
________ nm
(f) 1 metre = ________ µm
16
(a) 1 metre = 1,000 millimetres
(b) 1 mm =
1,000 microns
(c) 1 µm =
1,000 nanometres
(d) 1 metre = 1,000,000,000 nm
(e) 1 mm =
1,000,000 nm
(f) 1 metre = 1,000,000 µm
16
17
(a) 10-3 metres =
________
(b) 10-6 metres =
________
(c) 10-9 metres =
________
(d) 10-10 metres =
________
17
(a) 10-3 metres =
1 millimetre
(b) 10-6 metres =
1 micron
(c) 10-9 metres =
1 nanometre
(d) 10-10 metres =
1 Angstrom
unit
(a) Electron microscope
‘measurement’ range: _____ to _____
(b) Light microscope ‘measurement’
range: _____ to _____
(c) Unaided human eye ‘range’:
_____ to _____
18
Unaided??
(a) Electron microscope
‘measurement’ range: 1 nm - 100 µm
(b) Light microscope ‘measurement’
range: 1 µm - 1 mm
(c) Unaided human eye ‘range’:
1 mm upwards
18
Unaided??
E.coli
E.coli
Prokaryotes: up close and personal
with E.coli
19
Unstained
19
Light microscope
20
Dark field
20
Light microscope
Differential interference
21
Light microscope
21
22
Phase contrast
22
Light microscope
Tick
23
Tick
23
Scanning electron microscope
24
24
Transmission electron microscope
25
25
Light microscope
26
26
Scanning electron microscope
Aphid
27
Aphid
27
Scanning electron microscope
28
28
Light microscope
29
29
Light microscope
30
30
Transmission electron microscope
31
31
Transmission electron microscope
32
32
Transmission electron microscope
33
33
Scanning electron microscope
34
34
Transmission electron microscope
35
35
Light microscope
36
36
Light microscope
37
37
Light microscope
Calculating magnification and cell
size
Calculating Actual size when the
magnification is unknown.
O=
OBSERVED
LENGTH
M=
MAGNIFICATION
A= Actual
size
Size of diagram (cm) x scale
length of scale bar (cm)