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Organelle Quiz
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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
2.1.6 h-l
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;
Remember – key definitions
• Cell, tissue, organ, organ system
• Organisation of the work:
• Cells: Animal/Plant - erythrocytes, neutrophils, epithelial cells,
sperm cells, palisade cells, root hair cells and guard cells;
• Tissues: Animal/Plant – epithelial, connective, muscle,
nervous, epidermal, vascular, meristematic, parenchyma, sclerenchyma,
collenchyma
• Organs: Animal/Plant heart, lungs, kidney etc, leaf root,
stem, (flower)
• Organ Systems: Animal/Plant – digestive, nervous, skin
etc, flower
How can cells be adapted?
• The amount of a certain organelle
• The shape of the cell
• The contents of the cell
Why is specialisation and
differentiation needed?
• Single celled organisms have a large SA/V ratio, all surfaces
are in contact with the external environment and the division
of labour is determined by the organelles.
• Multicellular organisms are large – have a smaller SA/V ratio.
• The majority of their cells are not in direct contact with the
external environment.
• This means they need specialised cells to carry out particular
functions.
What are you like?
Cell Type
Phagocytic white
blood cell
Red blood cell
(erythrocyte)
Squamous
epithelial cell
Skeletal muscle cell
Ciliated epitheial
cell
Motor neurone
Sperm cell
Role of cell
Specialised
features
Picture
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 lysosomes – enzymes to digest
pathogens
• Multi-lobed nucleus – makes it easier to
squeeze between gaps between cells to enter
tissues
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
Now do your own table/revision
resource
• Plant cells that you need to know about
• palisade cells, root hair cells and guard cells
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;
Peer mark your resources
• How well does the resource answer each of the
Learning Objectives? Give a score for each
objective.
• Think about detail (2), clarity (2)
• Accuracy of detail, drawings (2)
• QWC, clever ways to remember ideas,
organisation (2)
• 1 mark if present, 2 marks if excellent
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 when changing shape due to water
entry
• Contain chloroplasts to undergo
photosynthesis
Root Hair Cell
Adaptations
• Large surface area
Mind map - tissues
• In 4s – Take one tissue each and summarise
the main ideas under three headings
• structure (what they are like),
• functions (what they do)
• organisation (how the cells are joined to form
tissue)
Hotseat!
Plenary
• Quick quiz – p158