Plant Reproduction Sexual Reproduction in flowering plants (3 min) http://www.youtube.com/watch?v=1OFF2qYvLag&safe=active Crash Course: Sexual Reproduction in Plants (10 min) http://www.youtube.com/watch?v=ExaQ8shhkw8&safe=active

Sexual Reproduction Flowering Plants (Angiosperms) Most successful and abundant modern day plants Reproductive structures found in flowers Seeds are enclosed with a “fruit” while developing

Flower Structure Stamens: Male portion of flower Filament stalk with anther tip produces pollen grains Often more than one Thick walled pollen grains contain 2 monoploid gametes

Pistil: (carpel) Female portion of flower Usually located in the center of the flower Stigma: at top of pistil, has sticky surface to receive pollen grains Style: fleshy tube supporting stigma, connecting it to ovary Ovary: contains ovules (monoploid gametes) that develop into seeds The ovary itself will develop into the “fruit”

Rings of modified leaves surround the reproductive organs of the flower Sepals: form a ring around the base of the flower Enclose and protect the flower bud before it blooms Petals: often brightly colored to attract pollinators

Pollination Transfer of pollen from anther to stigma Self Pollination: flower pollinates itself Cross Pollination: pollen is taken from one plant to another (get more genetic variation) Agents of Pollination: Wind, birds, bats, bees, butterflies, wasps, flies, ants Plant often adapted to attract a specific pollinator with showy petals, aromas and nectar The Biggest Flower in the World: (3 min) http://www.youtube.com/watch?v=FHaWu2rcP94&safe=active

Fertilization Pollen grains land on stigma and grow pollen tubes that grows down through the style to the ovary and enter the ovule Double Fertilization Occurs: One sperm fertilizes egg to make diploid zygote One sperm fertilizes 2 polar bodies forming triploid endosperm (3n) This becomes the tissue that stores food for the embryo

Fruits and Seeds Each ovule develops into a seed 1 minute: http://videos.howstuffworks.com/discovery/30701-assignment-discovery-seed-dispersal-video.htm Each ovule develops into a seed Ovary walls thicken around the seed and develop into the fruit

Seed Structure Seed Coat: Cotyledon: Epicotyl: Hypocotyl: tough protective coating Has a scar where it was attached to the ovary Cotyledon: stores food for early growth of embryo when seed germinates Epicotyl: develops into stems and leaves Hypocotyl: develops into roots

Seed Dispersal Dispersal: Plants have many adaptations to help them scatter their seeds Fruit dries and bursts open (snapdragon) Carried by wind (dandelion) Carried by water (coconut) Burrs, hooks Fruits eaten by birds or other animals and pooped out Seed Dispersal:http://www.youtube.com/watch?v=rhp5k5ptSx0&safe=active

Seed Germination Germination: “seed hatching” Seeds need water, oxygen, proper temperature Germination: (1 min) http://science.howstuffworks.com/life/30704-assignment-discovery-germination-of-a-seed-video.htm