Transcript Embryo Sac
Flowers Laboratory Flower Structure and Interactions with Pollinators • Flowers are modified leaves, specialized for reproduction. • Flowers form on the diploid Sporophyte • Flower parts undergo meiosis to produce haploid Gametophytes – pollen grain – embryo sac Flower Sporophyte Pollen grains embryo sac Gametophytes Flowering Plant Reproduction Pistil Stamen A Complete Flower Has Both Male and Female Parts Anther Filament Stigma Petal Style Sepal Ovary All Petals=Corolla All Sepals=Calyx Plant Reproduction Flower Part Function Sepals Enclose and protect bud Petals Attract pollinators Stamen Produce pollen in anther Pistil (carpel) Produce ovule in ovary Mature Sporophyte Megaspore meiosis (female) Microspore (male) Sperm mitosis, Cells mitosis, differentiation, differentiation growth mitosis, Male Gametophyte differentiation Egg (Pollen) Cell fusion to form zygote in ovary Female Diploid Gametophyte 2n (Embryo Sac) Haploid 1n Flowering Plant Life Cycle Mature Pollen Grain Sperm Cells Tube Cell Nucleus 2. pollen tubes grow down style to ovary Sperm 1. pollen grains land on stigma Stigma Style 3a Fusion of 2nd sperm + two polar nuclei 3. double fertilization 3b Fusion of sperm + egg Ovule Polar nuclei Ovary Egg Pollination and Fertilization in a Flower Development of Fruit and Seeds From Flower Parts Endosperm Triploid Endosperm Cell Fresh Fruit Ovary Seed Integument Coat Zygote Embryo Seed = fertilized ovule = embryo + endosperm + seed coat Fruit = ovary wall, mechanism for seed dispersal Comparing Monocot and Dicot Plants Flower Symmetry Radial Symmetry (Regular) Bilateral Symmetry (Irregular) Ovary Position Superior Ovary Inferior Ovary Coevolution of Plant and Pollinator Wind Pollination Pollination by Beetles Pollination by Ants Pollination by Carrion Flies Pollination by Mammals Pollination by Wasps Pollination by Bees Ultraviolet Patterns Guide Bees to Nectar Human Vision Bee Vision Impersonating a Pollinator Pollination by Moths Pollination by Hummingbirds Pollination by Butterflies Composite Flowers CLEAN UP! • Leave plant specimens in orderly arrays • Discard dissected flower parts in the trash • Return any microscopes to their cabinets Thank you! Worksheet • Turn in pages 151-153 from lab manual – Record your answer and reasoning for any 10 specimens, making sure to write the answer on the line that matches the specimen number • Be sure your instructor checks your completed worksheet before you leave the lab