2General Characteristics: EukaryotesMulticellular; organized into tissues, organs and systemsCell walls present (cellulose)Autotrophs; contain chloroplastsReproduce sexually
3General Characteristics What Plants need:Sunlight to carry out photosynthesisWater and mineralsGas exchange (oxygen for respiration; carbon dioxide for photosynthesis)Movement of water and nutrients
4Origin: Probably descendants of green algae (Protist) Algae always live in water, which supports nutrient transport & absorption, stable environment, gamete transfer & development, and structural support.
5Origin: Life on land requires many adaptations protection from drying outgas exchange with surrounding airtransport for water & nutrients through multicellular bodysupport to grow upright on land
6Adaptations & Specialized Structures: Cuticle – a waxy layer from the outer epidermis of the plant surface that prevents water loss to the external environment (osmosis) Stomata – small openings on the leaf surface to allow gas exchangeGuard Cells – surround the stomata to control the opening and closing of the pore
7Adaptations & Specialized Structures: Vascular Tissues – tubes that allow transport of water and nutrients to different parts of the plant; form vascular bundles throughout the plant* Xylem – transport water and minerals up from the roots throughout the plant* Phloem – transport food (sugars) from the leaves and stems, where it is made, to other parts for use or storage
9Adaptations & Specialized Structures: Cell Walls – rigid structure provide structural support for growth on land.Roots – specialized tissues (usually underground) that absorb water & minerals, anchor the plant for upward growth, and store food as starch* Root hairs – extensions that increase absorption
10Adaptations & Specialized Structures: Stems – tissues that support the above-ground parts of the plant and allow movement of materials between leaves and roots. Also store food.
11Adaptations & Specialized Structures: Flower – assist in pollination process by attracting birds and insects with color or scent. Contain the male and female reproductive organs.* Sepal – protects the young bud* Petal – attracts pollinators, serve as a landing pad* Stamen – male reproductive organ- Anther – produces male gametes (pollen)- Filament – supports the anther
12Adaptations & Specialized Structures: Pistil – female reproductive organOvary – swollen base of the pistil where ovules (eggs) are producedStyle – neck of the pistil, allows for sperm transfer to ovaryStigma – sticky or rough surface at the tip of the styleSeed – a plant embryo with a food supply enclosed in a tough, protective coat; allows for success through harsh conditions
13Life Cycle of Plants Alternation of generations: haploid gametophyte (gamete producing plant)diploid sporophyte (spore producing plant)Plants can reproduce asexually with leaves, stems and roots.regenerationvegetative propagation (stolons, rhizomes, tubers and bulbs)
14Classification within the Kingdom: Nonvascular Plants – lack the specialized tissues to transport water * individuals are very small; only a few cells thick to allow diffusion of nutrients and water * grow in clumps or “carpets” in very moist environments *depend on water for reproduction * examples – moss, hornworts and liverworts (Phyla: bryophytes)
15Classification within the Kingdom: Vascular Plants – have tube-like tissues to transport water and nutrients * requires development of different tissues (roots, stem, leaves) for success on land * allows for upright growth & development into complex organisms * simple examples – club moss, horsetails & ferns - require growth in moist environments for sperm dispersal, produce spores
16Classification within the Kingdom: Gymnosperms – non-flowering vascular plants * leaves are in the form of needles or scales * seeds are not enclosed in fruit * many produce cones to protect seeds (conifers) * do not produce flowers * sperm is protected in a hard coat called pollen and are dispersed by wind * very hard cell walls allow for tall growth (woody tissue)
18Classification within the Kingdom: Angiosperms – flowering vascular plants * seeds are enclosed in fruit, a ripened ovary * leaves are flat * have woody and non-woody stems * divided into 2 groups based on the number of cotyledons (leaf-like parts of the plant embryo in the seed)
20Classification within the Kingdom: Monocots – one cotyledon on seed * flower parts in multiples of 3 * vascular bundles scattered throughout the stem * parallel veins in narrow leaves * fibrous roots * examples – grasses, corn, rice, oats, wheat, tulips Dicots – two cotyledons on seed * flower parts in multiples of 4 or 5 * vascular bundles form a ring in the stem * branching, netlike veins in broad leaves * tap roots * examples – oak & maple trees, garden flowers, beans, fruit trees, broccoli, carrots
22Tropisms Occur when plants respond to external stimuli Cause a change in plant growthCan be negative (away from stimuli) or positive (toward stimuli)
23Plant HormonesAuxin - Stimulates cell elongation; involved in phototropism, gravitropism, stimulates fruit development. Too much can prevent growth.Abscisic Acid – slows or stops growth and cell division in plants.Gibberellin - Stimulates shoot elongation, stimulates flowering in biennials.Ethylene - Stimulates fruit ripening
24Assignment: Sketch the general life cycle of plants (p 664) Sketch and label the structure of a flower.How do plants obtain energy?What are the plant tropisms? Give examples.Draw the cladogram on page 613What would be the derived characters in this cladogram?From which organisms did plants evolve? Which kingdom does that ancestor belong to?
25Define the following terms PlantCuticleStomataVascular systemPollen grainSeedPollinationGymnospermAngiospermConeFlowerFruitDicotXylemPhloemRoot hairFibrous rootTap rootGuard cellAlternation of generationsSporophyteGametophyteOvaryThigmotropismGravitropismPhotoperiodismGerminationRegenerationVegetative reproductionTropismCotyledonMonocotPhototropism