Angiosperms – vessel seed

•Seed plants that produce flowers • Seeds are enclosed in fruits • Live almost anywhere on earth, even the Arctic and deserts

Flowers Their function --- reproduction.

Structure – (note - some may have only male parts, some lack petals.) p.277

Sepals – leaflike structures that enclose the bud. - protect the developing flower.

Petals – usually the most colorful part.

- pollinators are attracted to brightness, patterns – males may see patterns similar to those exhibited by females.

Stamens – male reproductive parts. filament – thin stalk positions anther/pollen for contacting pollinators. anther – produces pollen at top of filament.

- pollen contains sperm cells.

Pistils – female reproductive parts. - found in the center of most flowers. - flowers have one pistil. stigma – sticky tip of the pistil that pollen sticks to. style – slender tube connecting stigma to hollow ovary. ovary – protects seeds as they develop. - contains one or more ovules, which contain the eggs.

Pollinators

- insects like bees, butterflies, flies

- bats, birds

Petal shape and brightness, scents attract them.

Are all scents pleasant? Rafflesia – pollinated by flies

Reproduction in Angiosperms

pollination – occurs when a grain of pollen falls on a stigma. - some occurs by wind. - most rely on pollinators nectar – sugar-rich food deep inside flower. - pollinator enters flower for nectar, brushes against pollen.

- pollen is carried to stigma of same flower or another one.

Fertilization - sperm cell from pollen moves down pollen tube.

- sperm joins with an egg cell inside an ovule within the ovary. - zygote begins developing into the seed’s embryo. - other parts of the ovule become the rest of the seed.

Fertilization

• Fruit development - ovary changes into fruit.

Fruit – ripened ovary and other structures that enclose one or more seeds. - animals eating fruits disperse seeds.

Types of angiosperms monocots – one cotyledon - flowers have 3 petals, or multiples of 3. - leaves are long, slender, with parallel veins. - vascular tissue bundles scattered randomly through stem.

Monocots

Monocot examples - grasses, including corn, wheat, rice. - lilies, tulips.

Dicots – two cotyledons

- flowers have 4 or 5 petals, or multiples of these. - leaves usually wide, with veins branching many times. - vascular tissue bundles arranged in a ring.

Dicots

Dicot examples- -oak and maple trees, roses and violets. - apples and beans .

Seed plants in use … gymnosperms – conifers provide lumber (pine, Douglas fir) and paper, rayon fibers, etc. angiosperms – food, clothing (cotton), medicine, furniture (cherry, maple, oak).

NOVA video -- flowers

http://www.teachersdomain.org/resource/oer08.sci.life.stru.flowers/

So what are we looking at ….?