Adaptation
Differentiation of cells
Differentiation
• Definition – give a dictionary definition of the word above.
• Give examples of differentiated cells
• Cellular differentiation is the process by which a less
specialised cell becomes a more specialised cell type
• Examples you need to be aware of are:
• erythrocytes (red blood cells) and neutrophils derived from
stem cells in bone marrow,
• xylem vessels and phloem sieve tubes from cambium;
Lesson 7 - Differentiation
Learning Objectives
• define the term
differentiation, with
reference to erythrocytes,
neutrophils
• describe and explain, how
cells of multicellular
organisms are specialised
for particular functions
• explain the meaning of the
terms tissue, organ and
organ system
Success Criteria
• Produce a resource to show
how each of the cell types is
differentiated
• Describe how the cell’s
differentiation allows it to
fulfill its role
• Produce a flow diagram to
show how blood cells
differentiate
Spec. Check
• describe and explain, with the aid of diagrams and
photographs, how cells of multicellular organisms are
specialised for particular functions,
• with reference to erythrocytes, neutrophils, epithelial
cells, sperm cells, palisade cells, root hair cells and
guard cells;
• explain, with the aid of diagrams and photographs,
how cells are organised into tissues, using squamous
and ciliated epithelia, xylem and phloem as examples;
How can cells be adapted?
• The amount of a certain organelle
• The shape of the cell
• The contents of the cell
Erythrocyte
Adaptations
Organelles
• No nucleus, mitochondria, Golgi apparatus,
rough endoplasmic reticulum
Shape
• Biconcave discs
Contents
• Contain lots of the protein haemoglobin
Neutrophil
Adaptations
Organelles
• Many lymphocytes
Sperm Cells
Adaptations
Organelles
• Many mitochondria
• Acrosome (lysosome)
Shape
• Streamlined
• Undulipodium
Content
• Half the number of chromosomes
Epithelial Cell
Squamous Epithelial Cell
• Flattened
• Smooth
• Secrete collagen and glycoproteins
Ciliated Epithelial Cell
• Covered in cilia
• Some release mucus
Palisade Cells
Adaptation
• Lots of chloroplasts for photosynthesis
• Laid end on
• Placed at top of leaf
Guard Cell
Adaptations
• Thick cell walls so inner cell wall does not
stretch
• Contain chloroplasts to undergo
photosynthesis
Root Hair Cell
Adaptations
• Large surface area