Download The Cell

Chapter3:3:The
TheCell
Cell
Chapter
What do you know about cells?
Objectives:
1. To define the term cells
2. To look at the basic structure of the cell
3. To identify the main parts of the cell
4. To distinguish between plant and animal cells
5. To identify the main parts of a microscope
6. To use a light microscope to examine plant
and animal cells under low and high power
All living things are made of cells.
Cell Structure
Cells are made up of 3 main parts:
1. Cell Membrane
2. Cytoplasm
3. Nucleus
Structure of Animal & Plant Cell
Parts of the cell and their function (job)
Part
Cell Membrane
Cytoplasm
Nucleus
Chloroplast
Cell Wall
Vacuole
Function
Parts & Functions of the Cell
Part
Function
Cell Membrane Protects the cell
Controls what enters & leavest the
cell
Cytoplasm
Place where chemical reactions
take place
Nucleus
Controls the cells activities
Chloroplast
Carries out photosynthesis
Cell Wall
Gives shape to the cell
Vacuole
Stores materials in the cell
Plant cells have all the
features present in
animal cells.
In addition, they have:
– A cell wall for
strength
– Chloroplasts
– Large vacuoles
Differences between Plant & Animal Cells
Plant Cells
Animal Cells
Cell wall present
No chloroplasts
Large vacuoles
Differences between plant
& Animal Cells
Plant Cells
Animal Cells
Cell wall present
No cell wall
Chloroplasts present
No chloroplasts
Large vacuoles
Small vacuoles or no
vacuoles
Is this a plant cell or an animal cell?
Give 2 reasons for your answer
Identify the main parts of the plant cell
C
A
D
B
E
E
A microscope is used to view small objects
in detail.
Identify the main parts of the microscope
C
A
B
D
E
The parts of a microscope and their functions are
as follows:
Part
Eye piece lens
Objective lens
Coarse Focus Wheel
Fine Focus Wheel
Stage
Mirror or light source
Function
Magnification using a light microscope
• The total magnification is calculated by multiplying
the power of the eyepiece by the power of the
objective lens being used.
Total magnification = eye piece lens X objective lens
CHAPTER 2
CELLS AND THE MICROSCOPE
• To examine animal or plant cells under a microscope:
– Make sure there is light passing through the opening in
the stage.
– Use the lowest power lens on the nosepiece.
– Clip the slide onto the stage.
– Turn the coarse focus knob to bring the stage close to
the slide.
CHAPTER 2
CELLS AND THE MICROSCOPE
– Turn the coarse focus knob to bring the lens away from
the slide.
– Move the slide so that the cells of interest are in the
centre.
– Adjust the amount of light passing through the slide.
– Change the objective lens to a higher power and refocus using the fine focus knob.
– Draw labelled diagrams of the cells at each
magnification.
Mandatory Experiment
To prepare a slide from plant tissue
and draw a diagram of the cells under
• To prepare a slide
from plant
magnification
tissue:
2
– Cut an onion CHAPTER
and remove a
thin layer
of cells.
CELLS
AND
THE MICROSCOPE
– Place the onion cells in water
on a microscope slide.
– Place a cover slip
over the onion cells.
CHAPTER 2
CELLS AND THE MICROSCOPE
• Draw a few drops of iodine solution across the cells
using absorbent paper.
Definitions
Tissues
A tissue is a group of similar cells with the
same function e.g. muscle tissue
Organ
An organ is made of many different tissues
working together e.g. the heart
Systems
A system is a group of organs working
together e.g. the circulatory system
Quiz
Plants
Tissue
Storage tissue
Organ
Flower
System
Shoot System
Animals