Presentation on theme: "Plant Cells, Tissues, and Organs"— Presentation transcript:
1 Plant Cells, Tissues, and Organs Section 2.1HomeworkPg. 62 #1-4
2 Chapter 2 Plants: From Cells to Systems In this chapter you will investigate:how plant cells specialize to form different tissuesthe link between cells, tissues, organs, and systems in plantsthe function of plant tissues and organshow organs work together to meet the needs of a plantdiseases that threaten plant tissues and organs
3 Organization in a multi-cellular organism Hierarchical levels of organization:OrganismOrgan systemsOrgansTissuesCellsMost complexLeast complex
5 simplest level of organization Heart muscle cellCirculatory systemHeart muscle tissueHeartZebraMaple treeEpidermal cellDermal tissueLeafShoot systemsimplest level of organizationa collection of similar cells that perform a particular functiona structure composed of two or more tissues working together to perform a complex body functionconsists of one or more organs and other structures that work together to perform a vital body functionmade up of many different organ systems working together
6 Plant stem cells are called meristematic cells. Meristematic cells have the potential to constantly divide and differentiate.photosynthesisgas exchangematerial transportsupport
7 Meristematic cells allow plants to constantly replace old organs. All growth in the plant is due to the division of meristem.Most occurs at the terminal bud.BudsRegions containing meristematic cells
8 Apical meristems Lateral meristems Found in buds at tips of roots and shoots.Responsible for increase in height.Lateral meristemsResponsible for increase in width.
9 Growth is controlled by chemicals called auxins. Produced by actively dividing cells.Signal neighbouring cells not to divide.
10 moves substances through plant Plant tissue typesMeristematic tissueDifferentiates into...Dermal tissuecovers outer surfaceVascular tissuemoves substances through plantGround tissuesupportive tissue
11 Every plant organ contains tissue from all three systems.
12 Dermal tissue Plant’s outermost layer Two types: Epidermal tissue thin layer of cells; covers non-woody surfaces of plantPeriderm tissuecovering that forms the woody surface on stems/large roots
13 Adaptations of dermal tissue FunctionRoot hairsMaximize water uptakeLeaf hairsContain chemical irritantsWaxy cuticleMakes surface waterproof
14 Vascular tissue system of tubes distributes absorbed water, minerals and nutrients
15 Xylem Phloem Dead, hollow tissue Transports water and minerals upwards from rootsPhloemLiving tissueTransports sugars produced by leaves, to the rest of the plant
16 Non-woody plant Woody plant Vascular tissue arranged in bundlesWoody plantVascular tissue forms a ring along trunk diameter
17 Ground tissue “Filler” tissue between dermal and vascular Variety of functions:photosynthesis, in the green parts of plantsstorage of carbohydrates in the rootsstorage and support in the stems
18 Plants have two organ systems SHOOT SYSTEMStem, leaves,flowers, fruit (if present)ROOT SYSTEMOne or more separate roots
19 The Root System Functions: Structure: anchor the plant absorb water and minerals from soilstore foodStructure:no leavesusually grows below groundcomposed of dermal tissueroot hairs maximize surface area
20 Spaces between cortex cells allow water to move from soil to the endodermis. Endodermis controls transport of water and minerals between cortex and xylem.
22 The Shoot System Structure: Functions: carry out photosynthesis (leaves)structural supporttransport substances throughout plantproduce flowers for sexual reproductionStructure:usually above groundcomponents:leavesstemflowers/fruit
23 Leaves Main site of photosynthesis: chloroplasts contain chlorophyll; absorb sunlight’s energyglucose is used for cellular respiration, plant growth, and energy storageCO2+ H2O + light energy ___________+ O2
25 Transparent outer layer, made of dermal tissue. EpidermisTransparent outer layer, made of dermal tissue.The upper epidermis secretes waxy cuticle.
26 The lower epidermis contains stomata (holes) for exchange of gases ((H2O, O2, CO2). opening/closing of stomata is controlled by guard cells
27 Middle layers, sandwiched between upper and lower epidermis MesophyllMiddle layers, sandwiched between upper and lower epidermisPalisade cells – Perform most of the photosynthesis in the leafcontain many chloroplaststightly-packed together
28 Spongy parenchyma cells – Loosely-packed to allow the movement of gases within the leaf
30 Vascular bundlesComposed of vascular tissue (xylem and phloem)arranged in bundlesvisible on the leaf as veins
31 Chloroplasts membrane- bound organelle contains more membrane- bound sacs (thylakoids)thylakoids are arranged in stacks (grana)
32 CO2+ H2O + light energy glucose + O2 Leaves have structures that help the plant obtain and keep the reactants for photosynthesis:CO2+ H2O + light energy glucose + O2Spongy parenchyma is loosely-packed to allow gases to circulate to all photosynthesizing cells.Cuticle is transparent to let light through.Palisade cells are tightly-packed to maximize the area exposed to the Sun.Guard cells close the stomata on hot days to prevent evaporation of water.
33 The StemFunctions:Support for shoot systemTransport of nutrients and water to leavesSpecialized stems: Food storage, protection, photosynthesis, reproductionUses: sugar cane, medicines, cork, wood and paper
34 Flowers Contain reproductive structures (male/female/both) Male Female OrganStamenCarpel/PistilGametePollen grainsEggs
35 Fertilization occurs by pollination, and produces seeds. contained in the fruitPollination can be assisted by wind, animals, or insects.
36 Flowers: AdaptationsTo attract pollinators, plants will have attractive flowers or nectar.