Multicellular Eukaryotic Autotrophic Sessile means cannot move Have cellulose in their cell walls

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2 Plant Characteristics: Multicellular Eukaryotic Autotrophic Sessile means cannot move Have cellulose in their cell walls chloroplast vacuole Golgi body Cell wall nucleus mitochondria Cell membrane 2

3 2 stages to photosynthesis STAGE 1 THE LIGHT REACTION CHLOROPLASTS CAPTURE ENERGY FROM THE SUN 3

4 STAGE 2 THE DARK REACTION LIGHT ENERGY USED TO PRODUCE SUGARS AND O 2 FROM H 2 0 AND CO 2 4

5 PLANT LIFE CYCLE Sporophyte plant = 2N Spores are 1N Zygote = 2N Gametophyte plant = 1N ALTERNATION OF GENERATIONS ALTERNATE PHASES (2N & 1N) IN PLANT LIFE CYCLE FERTILIZATION = EGG + SPERM (the joining together of the egg and sperm 5

6 1N = Haploid = ½ the chromosomes Gametophyte = 1N 2N = Diploid = full set of chromosomes Sporophyte = 2N ZYGOTE= SPERM + EGG (it s the product of fertilization) =2N (diploid) it s a fertilized egg!! Plants evolved from the GREEN ALGAE (PROTISTA) Contain chlorophyll a+b Fossil evidence (440,000,000 years ago) 6

7 Adaptations which allowed plants to grow on land: Cuticle waxy covering to prevent water loss o Keeps plant from drying out Modified leaves (Shapes & Stomata) Broad flat leaves better for photosynthesis Leaves placed for best light absorption Stomata for better gas exchange **Opening in the underside of the leaf Roots take in water and anchor the plant Stem support for growth and food storage 7

8 Vascular development transport food and water *simple plants use only diffusion height limited!! Vascular system allows water and nutrients to go to the whole plant now can be TALL plants!! Seed development protects gametes Gametes are the sex cells Alternation of generations (Sporophyte & Gametophyte) Sexual reproduction 8

9 Two major groups 1. NON VASCULAR PLANTS No developed system for transporting H 2 O & nutrients Must get H 2 O DIRECTLY from their surroundings Plants are small, LOW TO THE GROUND and must live in shady, DAMP places Hornwort Liverwort 9

10 2. VASCULAR PLANTS Have a transport system!! Now can live on Dry Land! Vascular tissue provides Support Strength Stability Plants without seeds NON VASCULAR PLANTS Phylum Bryophyta Low growing (short) plants Live in moist (wet) areas =get water from surroundings Water needed for reproduction 10

11 EXAMPLES OF NON VASCULAR NO SEEDS: Mosses: very diverse group, found everywhere GAMETOPHYTE GENERATION SEEN 11

12 Liverwort named for the gametophyte Hornwort-named for the sporophyte 12

13 SEEDLESS Vascular Plants Characteristics: Have VASCULAR tissue Reproduce using SPORES Tall plants Grows in moist surroundings Examples: Ferns: cuticle upper surface blade Rhizome Roots Underground stem of a fern SORI GROUPS OF SPORES 13

14 CLUB MOSSES HORSETAIL 14

15 2 Types: Xylem: transports water Phloem: transports food (from photosynthesis) 15

16 YAY!! Now H 2 O NOT needed for fertilization!!! This is a BIG DEAL. Plants can now move away from the edge of the water. POLLEN is now the sperm cell (male) SEEDS o occur after fertilization Egg + Pollen = Seed Definition: Seeds are structures that contain a young plant inside a protective covering STOPS THE SEED FROM DRYING OUT 16

17 3 MAIN PARTS EMBRYO Has all the main parts of the adult plant COTYLEDONS can be stored food seed leaf SEED COAT keeps embryo from drying out allows seed to remain inactive for long periods CORN STEM ROOT 17

18 ***Must have enough water! Seed absorbs H 2 O*** Embryo begins to grow again and pushes out of the seed Roots grow DOWNWARD Stems grow UPWARD *** SEEDS CALLED SEEDLING ONCE THE PLANT S LEAVES ARE SEEN*** 18

19 NEEDED FOR SUCCESS OF PLANTS (private life of plants travelling 10:05-22) Animals o Attachment o Digestive tract (elephants, birds) H 2 O Wind Ejection ROOTS Function: 1) Anchor plants 2) Absorb H 2 O & minerals for Soil 3) Sometimes store food 19

20 2 types of roots Fibrous Roots Tap Root Dense tangle of roots, takes lots of dirt with it when pulled out Example: Lawn grass One LONG main root Smaller roots branch off Example: Carrots & Dandylions Corn & Onions Root Structure Root cap: protects the root from injury Dividing cells: area of new growth 20

21 Root hairs: increase water absorption and minerals absorption by increasing the surface area Root hair Area of dividing cells = MITOSIS ROOT CAP See page 267 Function: Support the plant (so leaves can get the most sun 21

22 Carries substances between the leaves and root Two types of stems Herbaceous Stems: -soft stems -example: pepper plants Woody Stems: -Hard, rigid stems -Example: roses, trees Annual Rings: Each ring of system (a band of light wood and a band of dark wood) represents one year s growth 22

23 LEAVES Cuticle Upper leaf cells Lower leaf cells Stomata phloem xylem VEIN Upper leaf cells: The most chloroplasts are located here Tightly packed together 23

24 Lower leaf cells: Widely spaced cells allows CO 2 to reach cells for photosynthesis Stomata: mouth tiny openings that allow gases to enter and exit the leaf Stomata close to retain H 2 O 1 2 GYMNOSPERMS ANGIOSPERMS "Naked" seeds oldest type of seed plant Flowering plants seeds are protected by fruit 24

25 Gymnosperms Naked seeds Cycadophyta (Cycads produce male & female cones) Ginkgophyta (Ginkgo seeds on female trees smell really bad) Coniferophyta (Conifers) Gnetophyta Ginko Cycad Conifers Cycad Cones (2 male 1 female) 25

26 female pine cone Male pine cone Anthophyta (Flowering / fruit plants ( species) Characteristics All produce Flowers All produce seeds that are covered in Fruit 26

27 STRUCTURE OF FLOWERS STAMEN PISTIL OR CARPAL Stamen: Male reproductive structure Anther produces the pollen Filament 27

28 Pistil: Female reproductive structure Stigma: sticky tip Style: connects the stigma and ovary Ovary: hollow structure that contains the ovules (developing seed) REPRODUCTION IN ANGIOSPERMS 1. Pollination (grain of pollen falls onto the stigma) 2. Fertilization(takes place in the ovary- Once fertilized the ZYGOTE begins to develop into the seeds embryo) 3. Fruit development and seed dispersal (after fertilization the ovary changes into the fruit) 28

29 Fibrous root Tap root 29

30 Definition: a plant s growth response toward or away from a stimulus Three important tropisms Thigmotropism Response to touch Vines coil due to a (+) response Phototropism Response to light Plants have a (+) response Gravitropism Response to gravity Roots have a (+) response Stems have a (-) response Hormones: Chemicals that affect growth and development 30

31 Photoperiodism: A plant s response to seasonal changes in the length of night and day Short day/long night Fall flowers Long day/short night Summer flowers Day neutral Not sensitive to periods of light and dark Ex: dandylions Dormancy: period when an organism s growth or activity stops 31

32 LIFE SPAN OF ANGIOSPERMS Annual complete life cycle in one season example: impatiens Biennial complete life cycle in 2 years 1 st year develop roots and short stems 2 nd year grow taller, produce flower & seeds then die Ex: parsley and celery Perennials Live more than 2 years 32