Introduction• A flower has a set of adaptations– Petals have modified leaves– Entire flower is a highly modified branch• Flower shape, scent, color attracts insects,thereby ensuring the reproduction of the plant
Flower• Function– To produce seeds for reproduction
Terminology• Whorl– Arrangement of three or more leaves,petals, or other organs radiating from theplant• Non-essential flower parts– Not directly involved in reproduction• Essential flower parts– Directly involved in reproduction
Parts of the Flower• Receptacle– Base of the flower
Parts of the Flower• Sepals– Non-essential parts of the flower– Compose the first whorl– Collectivelyknown as the calyx
Parts of the Flower• Petals– Non-essential parts of the flower• Compose the second whorl• Collectively known as the corolla
Parts of the Flower• Stamen– Essential flower parts• Compose the third whorl• Male reproductive organ–Anther : Produces pollen (containssperm cells)–Filament : Supports the anther
Parts of the Flower• Carpels– Essential flower parts– Compose the last, fourth whorl– Usually fused to make a single pistil– Female reproductive organ
Carpels vs. Pistils• (A) shows a single pistilconsisting of severalfused carpels• (B) shows severalpistils, each consistingof a single carpel
Parts of the flower• Female reproductive organ– Ovary : Swollen base of the pistil (containsovules, which contain egg cells)– Style: Stalk of the pistil– Stigma: Tip of the pistil, sticky to capture fallingpollen
Types of Flowers• Perfect– Has both pistils andstamens in the same flower– Have all 4 whorls of modified leaves• Imperfect– Has either pistil or stamens in the same flower– Missing one or more flower parts– Two types• Monoecious• Dioecious
Imperfect Flowers• Monoecious– “Same house”– Separate male and female flowers on thesame plant– Example• Corn
Imperfect Flowers• Dioecious– “Two houses”– Flowers are all male or all female on thesame plant– Example• Ginko tree–Most are male–Female produces seeds with foul odor
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