Higher Human Biology Differentiation unspecialised cells become altered and adapted perform a specialised function permanent tissue Division of labour Multicellular organisms Differentiation in Human Cells ID: 622963
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Slide1
Differentiation
Higher Human BiologySlide2
Differentiation
unspecialised
cells become altered and adapted
perform a
specialised
function
permanent tissue
Division of
labour
Multicellular organismsSlide3
Differentiation in Human Cells
Fertilised
egg (zygote)
Divides rapidly by mitosis and cell division to form an embryo
Many different
specialised cells created – each adapted to suit its function.Slide4
Each embryonic cell contains all the genes for constructing the whole organism
Unlike adult cells these genes are either switched on/ have the potential to be switched on. Slide5
As embryological development proceeds embryonic cells become differentiated and
specialised
in;
Structure
Biochemical properties
Perfectly adapted to carry out particular functions.Slide6
Somatic cells
B Lymphocyte
Hyaline cartilage
Smooth muscleSlide7
Somatic cells
Ciliated epithelial cell
Red blood cell
platelets
neutrophilSlide8
Somatic cells
Cardiac muscle
Nerve cells
Squamous epithelial cells
T lymphocyteSlide9
Selective Gene Expression
Differentiated cells only express the genes that code for the proteins specific to the workings of that particular cell.Slide10
Nerve cells
- genes that code for formation of neurotransmitter substances switched on
- genes for production of mucus switched off.
Goblet cells
– genes that code for mucus production switched on
- Genes that code for neurotransmitters switched off.Slide11
Only a fraction of genes in a
specialised
cell are expressed.
Approx
3 – 5 % in a typical human cell.