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Organelle Quiz. B. D. A. C. H. F. E. G. Adaptation. Differentiation of cells. Differentiation. Definition – give a dictionary definition of the word above. Give examples of differentiated cells
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Organelle Quiz B D A C H F E G
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 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 • 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
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.
Adaptations Organelles • No nucleus, mitochondria, Golgi apparatus, rough endoplasmic reticulum Shape • Biconcave discs Contents • Contain lots of the protein haemoglobin
Adaptations Organelles • Many lysosomes – enzymes to digest pathogens • Multi-lobed nucleus – makes it easier to squeeze between gaps between cells to enter tissues
Adaptations Organelles • Many mitochondria • Acrosome (lysosome) Shape • Streamlined • Undulipodium Content • Half the number of chromosomes
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
Adaptation • Lots of chloroplasts for photosynthesis • Laid end on • Placed at top of leaf
Adaptations • Thick cell walls so inner cell wall does not stretch when changing shape due to water entry • Contain chloroplasts to undergo photosynthesis
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