IntroductionCells are the basic units of organismsCells can only be observed under microscopeTwo basic types of cells:Animal CellPlant Cell

Plant CellMade of cellulose which forms very thin fibresStrong and rigidIn plant cells only

Plant CellProtect and support the enclosed substances (protoplasm)Resist entry of excess water into the cellGive shape to the cellCell wall

Plant CellA dead layerLarge empty spaces present between cellulose fibresfreely permeableCell wall

Plant CellLies immediately against the cell wallMade of protein and lipid Selectively permeable

Plant CellA living layerCan control the movement of materials into and out of the cell

Cell membrane

Plant CellJelly-like substance enclosed by cell membraneProvide a medium for chemical reactions to take place

Plant CellContains organelles and granules :e.g. chloroplast e.g. mitochondrionCytoplasm

Organellesvery small size can only be observed under electron microscopehas specific functions in cytoplasm

Plant CellContain the green pigment chlorophyllTo trap light energy, to make food by photosynthesis

Plant CellContain starch grains (products of photosynthesis) Chloroplast

Plant CellRod shapeFor respiration

Plant CellActive cells ( eg. sperms, liver cells) have more mitochondriaMitochondrion ( mitochondria )

Plant CellStarch granulesOil dropletsCrystals of insoluble wastes

Plant Celllarge central vacuoleSurrounded by tonoplastContains cell sapa solution of chemicals (sugars, proteins, mineral salts, wastes, pigments)

Plant CellControl the normal activities of the cellBounded by a nuclear membraneContains thread-like chromosomes

Plant CellEach cell has fixed number of chromosomesChromosomes carry genesgenes control cell characteristicsNucleus

Different kinds of plant cells

Animal cellmitochondrionnucleusglycogen granulecell membranecytoplasmNo cell wall and chloroplastStores glycogen granules and oil droplets in the cytoplasmvacuole

Different kinds of animal cells

Similarities between plant cells and animal cellsBoth have a cell membrane surrounding the cytoplasmBoth have a nucleusBoth contain mitochondria

Differences between plant cells and animal cellsAnimal cellsPlant cellsRelatively smaller in sizeIrregular shapeNo cell wallRelatively larger in sizeRegular shapeCell wall present

Differences between plant cells and animal cellsAnimal cellsPlant cellsVacuole small or absentGlycogen granules as food storeNucleus at the centreLarge central vacuoleStarch granules as food storeNucleus near cell wall

MicroscopeInstrument for observing small objects

Different parts of a microscope

The cell as the basic unit of lifeCell is the smallest unit of living organismsUnicellular organisms are made of one cell onlyThe cells of multicellular organisms are specialized to perform different functionse.g. mesophyll cells for photosynthesis and root hair cells for water absorption

Levels of organizationCells are grouped together and work as a whole to perform special functions

TissueA group of similar cells to perform a particular functionAnimals : epithelial tissue, muscular tissuePlants : vascular tissue, mesophyll

OrganDifferent tissues group together to carry out specialized functionsHeart : consists of muscles, nervous tissue and blood vesselsLeaf : consists of epidermis, mesophyll and vascular tissue

The Structures of a LeafStomaAir SpaceSpongy Mesophyll CellChloroplastPalisade Mesophyll Cell

The Structures of a Heart

SystemSeveral organs and tissues work together to carry out a particular set of functions in a co-ordinated wayHuman : digestive, respiratory, excretory, circulatory and reproductive systemsPlant : root and shoot systems

System in our body examples of systems :Digestive SystemRespiratory SystemCirculatory SystemNervous SystemReproductive System

The Respiratory System

The Circulatory System

The Nervous System

Male Reproductive System

Female Reproductive System

Level of Organizationcells (e.g. muscle cells, nerve cells)tissues (e.g. muscle, epithelium)organs (e.g. heart, lungs, stomach)systems (e.g. circulatory system)organisms (e.g. man)

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