Organelle Quiz A B C D E F G H

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; h-l

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 TypeRole of cellSpecialised features Picture Phagocytic white blood cell Red blood cell (erythrocyte) Squamous epithelial cell Skeletal muscle cell Ciliated epitheial cell Motor neurone Sperm 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 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