Biology Lecture Slide Week 1

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Biology Lecture Slide Week 1

Transcript of Biology Lecture Slide Week 1

  • 1.CELL AS A UNIT OF LIFE

2. Cell theoryProkaryotic and Eukaryotic cellsMicroscopic structure of plant andanimal cellsCells as basic units of living organismsare grouped into tissue and organsabout this chapter 3. kuman di seberang laut nampak,gajah di depan mata tak nampak 4. Definition of CellA cell is the smallest unit that iscapable of performing lifefunctions. 5. Examples of CellsAmoeba ProteusPlant StemRed Blood CellNerve CellBacteria 6. 3.1 Early DiscoveriesMid 1600sRobert Hooke observed and describedcells in corkLate1600sAntony van Leeuwenhoek observedsperm, microorganisms1820sRobert Brown observed and namednucleus in plant cells 7. Developing Cell TheoryRudolf VirchowTheodorSchwannSchlieden Plant growth, hestated in 1837, came aboutthrough the production of newcells, which, he speculated, werepropagated from the nuclei ofold cells, i.e., all plants arecomposed of cells.Matthias Schleiden 8. CELL THEORY 9. Living things are made up of cellsThe cell is the basic unit ofstructureCells come only from preexistingcells 10. CellSmallest unit oflifeCan survive on itsown or haspotential to do soIs highlyorganized formetabolismSenses andresponds toenvironmentHas potential toreproduce 11. Two types of cells :Prokaryotic cellsNo true nucleus or organellese.g : Eubacteria and cyanobacteriaEukaryotic cellsNucleus and organelles that surrounded by amembranee.g: protozoa, algae, fungi, plants and animals 12. MicroscopesCreate detailed images of something that isotherwise too small to seeLight microscopesSimple or compoundElectron microscopesTransmission EM or Scanning EM 13. Slide 1ocular lensobjective lensstagecondenserilluminatorprismsource of illuminationFigure 4.6bPage 58Slide 1ocular lensobjective lensstagecondenserilluminatorprismsource of illuminationFigure 4.6bPage 58 14. Slide 9Click to viewanimation.Light microscopy animation.Animation 15. Slide 10viewing screenprojector lensintermediate lensobjective lensspecimencondenser lensaccelerated electron flow(top to bottom)Figure 4.7Page 58 16. Slide 12frog egg3 mmtypical plant cell10-100 mmitochondrion1-5 mchloroplast2-10 mhuman redblood cell7-8 mdiameterTrypanosoma(protozoan)25 m longChlamydomonas(green alga)5-6 m longpolio virus30 nmHIV(AIDS virus)100 nmT4 bacteriophage225 nm longtobacco mosaic virus300 nm longDNA molecule2 nm diameterUnaided VisionElectron Microscope (Down To 0.5 Nm)Light Microscope (Down To 200 Nm)Escherichia coli (bacterium)1-5 m long1 centimeter (cm) = 1/100 meter, or 0.4 inch1 millimeter (mm) = 1/1,000 meter1 micrometer (m) = 1/1,000,000 meter1 nanometer (nm) = 1/1,000,000,000 meter1 meter = 102 cm = 103 mm = 106 m = 109 nm1 mm 100 m 10 m 1 m 100 nm 10 nm 1 nm 0.5 nmFigure 4.8Page 59 17. Limitations of Light MicroscopyWavelengths of light are 400-750 nmIf a structure is less than one-half of awavelength long, it will not be visibleLight microscopes can resolve objects down toabout 200 nm in size 18. Electron MicroscopyUses streams of accelerated electronsrather than lightElectrons are focused by magnets ratherthan glass lensesCan resolve structures down to 0.5 nm 19. PROKARYOTIC CELLS&EUKARYOTIC CELLS 20. The prokaryotic cell is much simpler in structure, lacking a nucleus and the other membrane-enclosed organelles of the eukaryotic cell. 21. 1. Organisms2. Cell size3. Cell division4. Cell walls5. Organelles6. Genetic material7. Flagella8. Respiration9. Photosynthesis10. Nitrogen fixation* refer handoutprokaryotes vs eukaryotes 22. MICROSCOPIC STRUCTURE OFPLANT AND ANIMAL CELLS 23. animal cells 24. plant cells 25. CELLS AS BASIC UNITS OFLIVING ORGANISMS AREGROUPED INTO TISSUE ANDORGANS 26. CELLS ARE GROUPED INTOTISSUE AND ORGANS 27. THE PLANT 28. PlantPlantGymnosperm- seed-bearing plantAngiosperm-flower-producing plant 29. TISSUESCells in plants and animals are groupedtogether in tissues.A tissue is a group of similar cells that areorganised to do a specific job 30. Angiosperm Body PlanVASCULAR TISSUESGROUND TISSUESSHOOT SYSTEMROOT SYSTEMEPIDERMISGround tissuesystemVascular tissuesystemDermal tissuesystem 31. shoot tip(terminal bud)lateral (axillary) budflowerEPIDERMISleafseeds(inside fruit)witheredcotyledonroot hairsroot tiproot capnodenodeinternodeVASCULAR TISSUESGROUND TISSUESSHOOT SYSTEMROOT SYSTEMprimary rootlateral rootOverview ofthe plantbody 32. Ground tissueVascular tissue 33. Meristems Regions where cell divisions produce plantgrowth Consist of unspecialised, dividing cells. Apical meristems Lengthen stems and roots Responsible for primary growth Lateral meristems Increase width of stems Responsible for secondary growth 34. activity atmeristemsnew cellselongateand start todifferentiateinto primarytissuesactivity atmeristemsnew cellselongateand start todifferentiateinto primarytissuesFigure 29.4Page 507Root apical meristemShoot apical meristem 35. activity atmeristemsnew cellselongateand start todifferentiateinto primarytissuesROOT APICAL MERISTEMApical meristem near all root tips gives rise toprotoderm, ground meristem, and procambiumThese give rise to the roots primary tissuesystems: epidermis, ground tissues, andvascular tissuesSHOOT APICAL MERISTEMSource of primary growth (lengthening)THREE PRIMARY MERISTEMSProtoderm epidermisGround meristem ground tissueProcambium primary vascular tissuesactivity atmeristemsnew cellselongateand start todifferentiateinto primarytissuesFigure 29.4Page 507Apical Meristems 36. vascular cambiumcork cambiumsecondaryphloemsecondaryxylemthickeningLATERAL MERISTEMSTwo lateral meristems in older stems and roots of woodyplants produce secondary growth (increases in diameter):Vascular cambium secondary vascular tissuesCork cambium periderm (replaces epidermis)Figure 29.4Page 507LATERAL MERISTEMS 37. Ground tissuesystem -serves basicfunctions:Food andwater storageVasculartissue system-distributeswater andsolutesDermal tissuesystemCovers andprotect plantsurfacesThree Plant Tissue system 38. GROUND TISSUE SYSTEM Predominantly cells in the leaf, stem, roots andstorage organse.g., potato tuber e.g., celery stem e.g., cherry seed 39. VASCULAR TISSUE SYSTEM The xylem andphloem made upthe plant vasculartissue system Food, water, andother substancesare transported andis continuousthroughout theplant. 40. DERMAL TISSUE SYSTEM (OR EPIDERMIS) Single layer of tightlypacked cells covering andprotecting the young partsof plant E.g., the waxy cuticle thathelp plant retain water inleaves and stems 41. Tissue DifferentiationProtodermGround meristemProcambiumEpidermisGround tissuePrimary vascular tissue 42. Simple Tissues Made up of only onetype of cellParenchymaCollenchymaSclerenchyma 43. Parenchyma: A Simple Tissue Most of a plants soft primary growth Pliable, thin walled, many sided cells Cells remain alive at maturity and retaincapacity to divide Mesophyll is a type that containschloroplastsParenchyma: A Simple Tissue Most of a plants soft primary growth Pliable, thin walled, many sided cells Cells remain alive at maturity and retaincapacity to divide Mesophyll is a type that containschloroplasts Ground tissue for fruits, stems andleaves. 44. Collenchyma: A Simple Tissue Specialized for support for primary tissues Makes stems strong but pliable Cells are elongated Walls thickened with pectin Alive at maturity 45. Scelerenchyma : A SimpleTissue Supports mature plant parts Protects many seeds Thick, lignified walls Dead at maturity Two types: Fibers: Long, tapered cells Sclereids: Stubbier cells 46. Complex TissuesXylemPhloemEpidermisComposed of a mix of cell types 47. XylemConducts water anddissolved mineralsConducting cells aredead and hollow atmaturityvesselmembertracheids 48. Phloem:A Complex Vascular Tissue Transports sugars Main conducting cellsare sieve-tubemembers Companion cells assistin the loading ofsugarssieve platesieve-tubemembercompanioncell 49. Epidermis:A Complex Plant Tissue Covers and protects plant surfaces Secretes a waxy, waterproofcuticle In plants with secondary growth,periderm replaces epidermis 50. Monocots and Dicots:Parallel veinsNetlike veins3 pores1 pore4 or 5 floralparts3 floralparts1 cotyledon 2 cotyledonsVascularbundlesdispersedVascularbundlesin ringMonocots and Dicots:Parallel veinsNetlike veins3 pores1 pore4 or 5 floralparts3 floralparts1 cotyledon 2 cotyledonsVascularbundlesdispersedVascularbundlesin ring 51. Shoot Developmentimmature leafground meristemprimary phloemprimary xylempithprocambiumcortexprocambiumprotodermshoot apical meristemprocambiumepidermisFigure 29.11Page 510 52. Internal Structure of a Dicot StemOutermost layer is epidermisCortex lies beneath epidermisRing of vascular bundles separates the cortexfrom the pithThe pith lies in the center of the stem 53. Internal Structureof a MonocotStem The vascular bundlesare distributedthroughout the groundtissue No division of groundtissue into cortex andpith 54. Ring of vascular bundlesdividing ground tissueinto cortex and pith Vascular bundles distributedthroughout ground tissueDicot MonocotInternal structure of Stems 55. Common Leaf FormspetiolebladeaxillarybudnodebladesheathnodeDICOT MONOCOT 56. Adapted for PhotosynthesisLeaves are usually thin High surface area-to-volume ratio Promotes diffusion of carbon dioxide in, oxygenoutLeaves are arranged to capture sunlight Are held perpendicular to rays of sun Arranged so they dont shade one another 57. Leaf StructureUPPEREPIDERMISPALISADEMESOPHYLLSPONGYMESOPHYLLLOWEREPIDERMISone stomacuticleO2CO2xylemphloem 58. Root SystemsTaproot system ofa California poppyFibrous root systemof a grass plantFigure 29.17Page 514 59. VASCULAR CYLINDER:endodermispericyclexylemphloemcortexepidermisfully grownroot hairVessels have matured; roothairs and vascular cylinderabout to formCells elongate; sieve tubes formand mature; vessel membersstart to formMost cells have stoppeddividingCells are dividing rapidly at apicaland primary meristemsquiescent centerroot capRoot StructureRoot cap coverstipApical meristemproduces the capCell divisions atthe apicalmeristem causethe root tole