Cell structure and organisation

Lower Secondary Biology

1. Cell Structure & Cell Structure &
OrganisationOrganisation

2. Chapter OutlineChapter Outline
(a) identify cell structures (including organelles) of typical
plant and animal cells from diagrams,
photomicrographs and as seen under the light
microscope using prepared slides and fresh material
treated with an appropriate temporary staining
technique:
• chloroplasts
• cell membrane
• cell wall
• cytoplasm
• cell vacuoles
• nucleus

3. Chapter OutlineChapter Outline
(b) identify the following organelles from diagrams and
electronmicrographs:
• mitochondria
• ribosomes
(c) state the functions of the organelles identified
above
(d) compare the structure of typical animal and plant
cells

4. Chapter OutlineChapter Outline
(e) state, in simple terms, the relationship between cell
function and cell structure for the following:
• absorption – root hair cells
• conduction and support – xylem vessels
• transport of oxygen – red blood cells
(f) differentiate cell, tissue, organ and organ system

5. What is a cell?What is a cell?
•Building blocks of life
•Simplest units of life
•Chemical reactions in the cell keeps us
alive

6. CellsCells
White Blood CellsRed Blood Cells

7. CellsCells
Embryonic Stem Cells

8. Other Examples of CellsOther Examples of Cells
Amoeba Proteus
Plant Stem
Red Blood Cell
Nerve Cell
Bacteria

9. CellsCells
What does a cell consists of?
Each living cell consists of living material called
protoplasm.
Protoplasm:
• Water makes up 70% of protoplasm
• Proteins
• Carbohydrates
• Fats

10. ProtoplasmProtoplasm
1)Cell Surface Membrane
2)Cytoplasm
3)Nucleus

11. Cell Structures in Plant Cell Structures in Plant
and Animal Cellsand Animal Cells
• nucleus
• cytoplasm
• cell membrane
• cell wall
• cell vacuoles
• ribosomes
• mitochondria
• chloroplasts

12. Animal and Plant CellsAnimal and Plant Cells
Animal Cell Plant Cell
Cell Structure and Function:
http://lgfl.skoool.co.uk/keystage3.aspx?id=63

13. Animal CellAnimal Cell

14. Animal CellAnimal Cell

15. Cell Surface MembraneCell Surface Membrane
•Surrounds the cytoplasm of the cell
•Partially permeable membrane
–Allows some substances but not all to move in
and out of the cell

16. NucleusNucleus
•Surrounded by a membrane
called the nuclear
envelope
•Contains one or more
nucleoli
•Contains chromatin
Functions of the nucleus:
1. Controls cell activities such as
cell growth and the repair of
worn-out parts
2. Essential for cell division
Nucleolus

17. CytoplasmCytoplasm
•Between the cell surface membrane and the nucleus
•Contains enzymes and organelles

18. Organelles in the CytoplasmOrganelles in the Cytoplasm
•Mitochondria
•Ribosomes
•Chloroplasts (only in plant cells)
•Cell vacuoles

19. MitochondriaMitochondria
•Aerobic respiration occurs in the mitochondria
•Energy production
•Energy used to perform cell activities such as
growth and reproduction

20. RibosomesRibosomes
•Required for protein synthesis in the cell

21. Vacuoles in Animal CellsVacuoles in Animal Cells
•A vacuole is a fluid-filled space
enclosed by a membrane
•Animal cells have many small
vacuoles that contain water and food
substances such as proteins and
carbohydrates

22. Label and identify the diagramLabel and identify the diagram
Pop Quiz!
A
B
C
D
F
E

23. Plant CellPlant Cell
Plant Cells:
http://lgfl.skoool.co.uk/keystage3.aspx?id=63

24. Plant CellPlant Cell

25. Differences Between Animal Differences Between Animal
and Plant Cellsand Plant Cells
Vacuoles are large, sap-
filled in plant cells
Vacuoles are small,
temporary in animal cells
Chloroplasts presentChloroplasts absent
Cell wall presentCell wall absent
Plant CellsAnimal Cells

26. Cell WallCell Wall
•Surrounds the cell surface
membrane
•Cell wall is made of
cellulose
•Protects the cell from injury
•Gives the plant cell a fixed
shape
•Cell wall is fully permeable

27. ChloroplastsChloroplasts
•Found only in plant
cells
•Chloroplasts contain a
green pigment called
chlorophyll
•Chlorophyll is essential
for photosynthesis, the
process by which plants
make food

28. Vacuoles in Plant CellsVacuoles in Plant Cells
•Plant cells usually have
a large central vacuole
which contains a liquid
called cell sap
•Cell sap contains
dissolved substances
such as sugars, mineral
salts and amino acids

29. Pop Quiz!
Label and identify the diagramLabel and identify the diagram
A
B
C
F
D
E

31. Specialised CellsSpecialised Cells
Red Blood Cell
Root Hair Cell
Nerve Cell
Sperm Cell
Egg Cell

32. Cell DifferentiationCell Differentiation
The process by which cells develop special
structures or lose certain structures to
enable them to carry out specific functions.
Hence, cells become differentiated to form
specialised cells.
The structure of each cell is adapted to
perform the specific functions of the cell.

33. Cell DifferentiationCell Differentiation

34. How is cell structure How is cell structure
related to cell function?related to cell function?
1) Red Blood Cell
Increased surface area
to volume ratio of the
cell. Hence, increased
transport of oxygen.
Circular biconcave shape
Carry more haemoglobin
which leads to increased
transport of oxygen.
No nucleus
Haemoglobin transports
oxygen from the lungs to
all parts of the body.
Contains haemoglobin
Adaptation to FunctionCell Structure

35. How is cell structure How is cell structure
related to cell function?related to cell function?
Lignin strengthens the
walls and prevents the
xylem vessels from
collapsing.
Lignified walls
Enables water to move
easily through the lumen.
Long hollow tubes (no
protoplasm)
Adaptation to FunctionCell Structure
2) Xylem Vessel

36. How is cell structure How is cell structure
related to cell function?related to cell function?
Increased surface area
to volume ratio of the cell
which leads to increased
absorption of water and
mineral salts from the
soil.
Long and narrow
Adaptation to FunctionCell Structure
3) Root Hair Cell
Specialised Plant and Animal Cells:
http://lgfl.skoool.co.uk/keystage3.aspx?id=63

37. How do cells How do cells
work together in work together in
a multi-cellular a multi-cellular
organism?organism?
Organisation in Living Things:
http://lgfl.skoool.co.uk/keystage3.aspx?id=63

38. TissueTissue
A tissue is a group of similar cells which work together
to perform a specific function.
Examples of tissues:
• Muscle, the lining of the intestine, the lining of the
lungs, phloem, root hair tissue
Connective
Tissue

39. OrganOrgan
Different tissues may be combined together to form
organs.
An organ is a structure made up of different tissues
working together to perform a specific function.
Examples of organs:
•Heart, lung, brain, leaf, root
Lungs

40. An organ is a structure made up of different
tissues working together to perform a
specific function.

41. Organ SystemOrgan System
Organs work together to
form organ systems.
Various systems work
together to make up the
entire organism.
Examples of organ systems:
•Circulatory system,
respiratory system,
digestive system, nervous
system and reproductive
system
Circulatory System

42. Organ SystemsOrgan Systems

43. SystemSystem OrgansOrgans
Digestive Esophagus
Stomach
Small intestine
Large intestine
Respiratory Trachea
Lungs
Organs work together to form organ
systems.

44. Pop Quiz!
Q1. Write out the order of cell
organisation within an organism.
Q2.Give an example of an animal
system with the order of cell
organisation stated above.

45. Organism
Pop Quiz!
Q1. Write out the order of cell
organisation within an organism.

46. •Intestinal cell  intestinal muscle 
small intestine  digestive system 
human
•Nerve cell  nerve tissue  eye 
sensory system  bird
Pop Quiz!
Q2.Give an example of an animal
system with the order of cell
organisation stated above.