3 Structure of a Flower 1.Pistil:female reproductive structure Slide # 3FilamentAntherStigmaStyleOvaryPistilPetalSepalOvuleStamen1.Pistil:female reproductive structureStigma: sticky tip; traps pollenStyle: slender tube; transports pollen from stigma to ovaryOvary: contains ovules; ovary develops into fruitOvule: contains egg cell which develops into a seed when fertilized
4 Structure of a Flower Stamen: male reproductive structure Slide # 4FilamentAntherStigmaStyleOvaryPistilPetalSepalOvuleStamenStamen: male reproductive structureFilament: thin stalk; supports antherAnther: knob-like structure; produces pollenPollen: contains microscopic cells that become sperm cells
6 Perfect & Imperfect Flowers Slide # 6Perfect Flower ~ has pistil & stamenImperfect Flower ~ only one sexWhich is male? Female?
7 Structure of a FlowerSlide # 7FilamentAntherStigmaStyleOvaryPistilPetalSepalOvuleStamenSepals: encloses & protects flower before it bloomsPetals: usually colorful & scented; attracts pollinators
8 What are the functions of each part? Slide # 8What are the functions of each part?
9 PollinationSlide # 9The transfer of pollen grains from the anther to the stigma.Pollination may be aided by wind, insects, and birds. In some instances, the colored petals act as a visual attractant for insects.If pollination occurred in a dry environment, the pollen would not dehydrate (dry up) due to a thick wall that surrounds it.Two types of pollination:1. Self-Pollination2. Cross-Pollination
10 Allows for variations due to the combination of two different plants. Self-PollinationSlide # 10The transfer of pollen grains from the anther to the stigma of the same plant.Cross-PollinationThe transfer of pollen grains from the anther of a flower on one plant to the stigma of a flower on a different plant.Allows for variations due to the combination of two different plants.
11 Pollen tube is an adaptation for internal fertilization. Slide # 11Following pollination, the pollen grain germinates to the stigma and forms a pollen tube.Pollen tube is an adaptation for internal fertilization.2 Haploid sperm cells travel down the pollen tube and only one fertilizes the egg in the ovule.
12 Fertilization and Embryo Development Slide # 12The union of a sperm cell and an egg cell results in the formation of a zygoteThe zygote undergoes development resulting in the formation of an embryo (ripened ovule)The ripened ovule (embryo) develops into the seedThe ripened ovary develops into the fruit
13 Structure of a Seed (embryo) Slide # 13Structure of a Seed (embryo)Hypocotyl: Develops intoroots and in somespecies lower stem.Radical: Develops in rootsEpicotyl: Develops intoleaves and upper stemCotyledon: Stored food forearly development of embryo(seed leaves)
15 forms from outer layer of ovule protects embryo Slide # 15Seed coat:forms from outer layer of ovuleprotects embryoEndosperm: food storage tissue(the other sperm creates this triploid (3n) structurewhen it fertilizes 2 polar bodies from oogenesis)
16 Monocots – seeds with one cotyledon (corn) Slide # 16Monocots & DicotsMonocots – seeds with one cotyledon (corn)Dicots – seeds with two cotyledons (bean, peanut)
17 Germination and Growth Slide # 17Germination and GrowthFruits are specialized structures which aid in seed dispersal. Seeds develop inside the fruit. If the temperature and moisture levels are sufficient, the dispersed seeds will germinate (activate and grow).Growth in most plants occurs in the meristems.The organs of a plant are developed in the meristems.Apical Meristems are found in the tips of roots and stems and cause the plant to grow in height.Lateral Meristems are between the xylem and phloem and cause the plant to grow in diameter (get wider).
18 Plant Responses and Adaptations Slide # 18PlantResponsesandAdaptations
19 Hormone Action on Plants Hormone-producingcellsHormone Action on PlantsSlide #19A. Plant cells can produce hormones (chemical messengers that travel throughout the plant causing other cells called target cells to respond)B. In plants, hormones control:Plant growth & developmentPlant responses to environmentMovementof hormoneTargetcellsCells in one blooming flower signals other blooms using hormones to open.
20 High Auxin ~ stimulates stem growth ~ inhibits root growth Plant HormonesSlide # 20AuxinHigh Auxin ~ stimulates stem growth~ inhibits root growthLow Auxin ~ reverse effectGibberellinIncreases stem growthIncreases fruit and seed development
21 Plant cells will send signals to one another to tell them: Slide # 21Plant cells will send signals to one another to tell them:When trees to drop their leaves.When to start new growth.When to cause fruit to ripen.When to cause flowers to bloom.When to cause seeds to sprout.Leaf DropTree BuddingFruitRipeningCactusBloomingSproutingCorn Seeds
22 Ethylene causes Fruit to Ripen Slide # 22Ethylene causes Fruit to RipenFruit tissues release a small amount of ethlyeneEthylene is a gaseous hormoneCauses fruits to ripenAs fruit become ripe, they produce more and more ethlyene, accelerating the ripening processFruit picked before ripened….spray w/ethylene at destination to ripenEthylene released by apples and tomatoes causes fruit to age quickly.What type of feedback?
23 Slide # 23Plant TropismsTropism: the way a plant grows in response to stimuli in the environment caused by an unequal distribution of auxin.Phototropism: growth response to light-Plants bend towards lightGeotrophism: growth response to gravity-plant roots grow down with gravity, shoots (stems) grow up against gravity and out of the soil.Thigmotropism: growth response to touch-vines grow up around trees, venus flytrap closes when leaves are touched
24 Thigmotrophism Phototropism Thigmotrophism Slide # 24What type of tropism is shown in these pictures?PhototropismGeotropismThigmotrophismPhototropismGeotropismThigmotrophism