Transcript Introduction to cells

Cell Biology
Introduction to cells
Learning Intentions
By investigating cell structure I can recognise and give the
function of a variety of cell organelles in typical plant and
animal cells.
Success criteria
• I can state which organelles are present in typical plant and
animal cells
• I can recognise and state the function of the cell wall,
chloroplasts, cell membrane, vacuole, nucleus and cytoplasm
• I can state why cells are stained to be viewed under a
microscope
Activity One
• Watch the video “Cells” closely
• Write down three facts about cells
Activity One
• Complete question one of your summary
booklet
• What is the name given to the basic units of
which all living things are made?
Cells
Animal and Plant Cells
Activity One
• Label the diagram of an
animal cell
– Nucleus
– Cytoplasm
– Cell membrane
• Label the diagram of a
plant cell
–
–
–
–
–
–
Nucleus
Cytoplasm
Cell membrane
Chloroplast
Vacuole
Cell wall
Animal Cell
Cytoplasm
Cell membrane
Nucleus
Plant Cell
Cell wall
Cell membrane
Chloroplast
Cytoplasm
Vacuole
Nucleus
Is it present Is it present
Name of Part
in plant
cells?
in animal
cells?
What is the function of this structure?
Nucleus
Yes
Yes
Controls cell activities
Cytoplasm
Yes
Yes
Where chemical reactions occur
Cell
membrane
Yes
Yes
Controls what enters and exits
the cell
Cell wall
Yes
No
Gives the cell shape and support
Some
No
Yes
No
Where food is produced by
photosynthesis
Contains sap
Chloroplast
Vacuole
Activity Two
• Watch the video “How to use a microscope”
• Choose one or more of the tissues below to
examine under the microscope.
– Cheek epithelium
– Onion epidermis
– Rhubarb /red onion epidermis
– Elodea
– Yeast
– bacteria (bio-slides)
Activity Two
Collect
• Microscope
• Microscope slides, 1 per
specimen
• Cover slips, 1 per specimen
• Distilled water
• Teat pipettes
• Forceps
• Stains
• Cotton wool bud (1 per
specimen)
Making a plant cell slide
Activity Two
Method
• Put a drop of Methylene
blue stain on a slide.
• Take a cotton bud and place
it against the inside of your
mouth. Remove from
mouth
• Dip the end of the cotton
bud into the stain and mix
• Place a cover slip on the
drop of stain, lowering it
gently using the cotton
bud.
• Observe your cells under a
microscope.
• Using a similar procedure
make slides of different
cells.
Safety Cautions
BE CAREFUL –
METHYLENE BLUE CAN
STAIN CLOTHES!!
PLACE ALL COTTON BUDS IN WASTE
BEAKER.
DO NOT HANDLE ANY COTTON
BUDS OR SLIDES OTHER THAN YOUR
OWN!!
SLIDES ARE MADE FROM
THIN GLASS.
TAKE CARE WHEN
HANDLING
Elodea
Cheek cells
• Red onion cells
• Yeast cells
Activity Two
• Find out the average cell length and breadth
Average cell length
Average cell breadth
5 cells across 2mm
10 cells across 2mm
2/5 = 0.4mm
2/10 = 0.2mm
2mm
Activity Two
• Explain why animal and plant cells should be
stained before examining them with a
microscope
Because the stain allows the parts of the
cell to be seen more clearly
Activity Four
• Watch the video “Types of cells”
• Complete the sentence
shape
• Specialised cells have a certain __________
function
suited to their ____________.
Specialised cells
Specialised cells
leaf
Self Evaluation
• I can state which organelles are present in typical plant and
animal cells
• I can recognise and state the function of the cell wall,
chloroplasts, cell membrane, vacuole, nucleus and cytoplasm
• I can state why cells are stained to be viewed under a
microscope
• I can state why specialised cells have a different shapes