Plant Reproduction, Fruit and Seed Dispersal The Problem of Fruit Plant Reproduction, Fruit and Seed Dispersal

How do plants reproduce? Some plants use flowers or cones in their reproductive processes. Pollen (male reproductive cell) Eggs (female reproductive cell)

How do plants reproduce Pollen may be carried from plant to plant by Wind Water Animals/ insects * If none of the above work, some will self-pollinate

Wind Pollination Wind-pollinated plants rely on wind to scatter their pollen. They do not need to attract animals so their flowers are usually UNSCENTED with small petals and sepals. Plants that use the wind produce huge amounts of pollen. Increasing the chances of fertilization. Pollen is usually smooth and light

Animal Pollination Flowers are used to attract animals to carry their pollen. Most have brightly colored petals or sweet scents to attract pollinators. Some may produce a sweet liquid called nectar. Some have patterns on their petals called nectar guides to help an insect find it. Pollen grains tend to be spiky so it sticks to the animals body.

Water pollination Pollen is dispersed into the water where it flows or is carried to other plants.

Problem 1 Flowers are pretty and take a ton of energy to create Why would a plant invest so much energy and time into a pretty flower, or into crazy reproductive parts?

To attract an make fertilization possible

Pollination Pollen lands on the stigma, moves through “style” and fertilizes an egg in the ovary.

Ovary becomes fruit

Problem 2 Why would a plant spend so much energy to create a fruit?

Seed Dispersal

Seed movement Animals might burry seed Animals might poop seed Squirrel burry acorn Animals might poop seed Apple, Berries, Vegetables Seed might float away Coconut

Seed Adaptations hooks called Burs are used to attach to animal fur Tasty seeds/fruits attract animals eat them Spores burst open from pods to disperse Float – coconuts float to another location Wings/ fuzz – make them light to be carried by the wind And many more

Why is moving seeds important?

Other Seed Dispersal Methods Burrs, Wind, Spores

Seed Dispersal Success Depends Upon Type of animals Environmental factors Number of seeds produced Seed landing in right spot

Review Why do seeds spend so much energy creating flowers and systems of fertilization? Why do seeds invest so much energy in fruit production?

Practice Why would a plant be more successful as a species if it is spread out over a wide geographical area? What are some factors that affect the successful germination of seeds?