Classification of Angiosperms The Flowering Plants
Two Major Groups Monocots Dicots Single cotyledon Parallel veins Flowers in multiples of 3’s Dicots Two cotyledons Netted veins Flowers in multiples of 2, 4 or 5
Monocot and Dicot plant
FRUITS SIMPLE AGGREGRATE MULTIPLE Dry (poppy seed, milkweed, wheat) Fleshy (peach, plumb, apple, tomato, grape) AGGREGRATE Flowers with several carpels Raspberry, strawberry MULTIPLE Cluster of flowers Pineapple
Simple, aggregrate and multiple fruit
SEED STRUCTURES Micropyle Plumule Hypocotyl Opening through which the pollen tube grows to deliver pollen to the ovary (ovules) Plumule Epicotyl + embryonic leaves First leaves to emerge during germination Hypocotyl Stem like area between radicle and cotyledon
SEED STRUCTURES (2) Radicle Cotyledon Hilum Seed Coat Embryonic root First to emerge from the seed during germination Cotyledon Fleshy part of the seed; food storage for plant embryo until germination Hilum Seed scar; where seed was attached to the ovary wall Seed Coat Covers and protects the seed during dormancy
Typical Seed
Germination Dormancy How do you know germination has occurred? Leaves Allows seed to germinate when conditions are favorable How do you know germination has occurred? Radicle emerges Leaves Photosynthesis begins Cotyledons no longer needed
Factors that Trigger Germination Water Oxygen Temperature Light Fire Freezing temps. Animal digestive tract Hormones
Plant Hormones Auxins Regulate plant growth
Hormones (2) Cytokinins Gibberellins Abscisic Acid Ethylene Promotes cell division (roots and stems) Gibberellins Promote growth Stimulate germination Abscisic Acid Inhibits growth of buds and germination Ethylene Gas that stimulates ripening of fruits
Hormones (3) Oligosaccharins Regulate growth and development Defense against disease
TROPISM Plant movement towards or away from a stimuli EXAMPLES Phototropism (light) Thigmotropism (touch) Gravitropism (gravity) Chemotropism (chemical/hormones) Hydrotropism (water)
THE FLOWER The reproductive structure for the flowering plant Perfect Flowers Both stamens and carpels present Self or cross pollination Imperfect Flowers Either stamens or carpels present Cross pollination only
Female Reproductive Parts Essential Carpel Pistil (fused carpels) Stigma, style, ovary Stigma Sticky to trap pollen Style Tube from stigma to ovary Ovary Holds the ovules
Female Flower Parts C A R P E L
Male Reproductive Parts Essential Stamen Male reproductive part Anther and filament Anther Produces pollen Filament Supports the anther
Male Flower Parts
Nonessential Flower Parts Petal Attract pollinators Top whorl Sepal Protect developing flower Bottom whorl Corolla Both whorls
Nonessential Flower Parts
Flowers