mr exham igcse - cell differentiation and organisation
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This is a presentation designed to help explain the section of the Edexcel IGCSE Biology course about cell differentiation and organisation. For more help with IGCSE Biology please visit mrexham.comTRANSCRIPT
MAKING SENSE OFCELL DIFFERENTIATION AND ORGANISATION
IGCSE Biology1.1 Life Processes
Cell differentiation and organisation
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Copyright © 2014 Henry Exham
Learning Objectives• Can you explain the organisation of an
organism using the following terms: organelles, cells, tissues, organs and organ systems?
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Cell Division• Multicellular organisms begin life as a single
fertilised egg cell called a ZYGOTE.• It then divides over and over again by MITOSIS
Zygote
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Embryo
Differentiation• As the developing embryo grows, cells
become specialised to carry out particular roles.
• This is called differentiation and is controlled by genes.
• As all cells have the same genes, some must be switched on and some switched off for this to work. This is discussed further in the IGCSE course.
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Specialised cells• Here are a few examples of specialised cells
that you will meet throughout the IGCSE Biology course.
• They will be mentioned briefly here as they will be explained fully in each relevant section.
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Nerve cell (Neurone)
• Very long cell for carrying impulses around the body along its axon.
• Insulated by a myelin sheath to make the signal travel quicker.
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Dendron
Cell body
Axon
Myelin sheath
Dendrites
Muscle
Sperm cell• Sperm cells have a tail for swimming.• The head contains the genes from the father
in the nucleus.• The acrosome digests its way into the egg for
fertilisation.
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TailNucleus
Acrosome
Palisade cell• This cell is found in the leaves of plants.• It is packed full of chloroplasts for
photosynthesis. • It is a regular shape in order to pack many into
the leaf.
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Xylem Vessel• This carries the water up the stem of a plant.• It is dead, hollow and strengthened in order
to do this.
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Cells tissues and organs• Each cell has many organelles inside it’s
cytoplasm to help it carry out its function.• Cells with a similar function are grouped
together in TISSUES.• A collection of similar tissues carrying out a
particular function is called an ORGAN.• In animals, jobs are usually carried out by
several different organs working together. This is called an ORGAN SYSTEM.
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Organelles
Cells
Tissues
Organs
Organ Systems
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Some of the key major human organs
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The 7 main organ systems• Digestive• Respiratory• Circulatory• Excretory• Nervous• Endocrine• Reproductive
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These will all be covered in detail
in the rest of IGCSE
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This PowerPoint is protected under copyright.It is designed for educational use. Either personal study or to be presented to a class. It may be edited or duplicated for these purposes only.It must not be shared or distributed online in any format.Some images used are under a separate creative commons license, these are clearly marked.
Copyright © 2014 Henry Exham
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