Presentación alvaro

Post on 23-Jun-2015

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reproducción de plantas

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José Rodríguez

José Benedicto

Pablo Martínez

Daniel Plano

Juan Pablo

Álvaro Cánovas

Flowers are the sexual ogans of flowering plants

Most flowers have got four main parts

petal

sepal

Pistil

Stamen

petalThe petals look like brightly coloured leaves

All the petals together form the corolla

They protect the inner parts of the flower

SepalThe sepals are small green leaves that grow at the base of the flower

All the sepals together form the calyx

PistilThe pistil is the plant’s female reproductive organ

It’s got three main parts

Stigma

Style

Ovary

Ovules

StamenAre the plant’s male reproductive organs

Each stamen has got a tube collect a filament and a sac called an anther

Each anther contains many grains of pollen

For a flowering plant to reproduce the stigma must receive pollen from an anthen

The movement of pollen grains fron the anther to the sitgma is called pollination

When a bee lands on a flower, some pollen sticks to the bee’s body. The bee carries this pollen to other flowers and pollinates them. This exchange of pollen between diferent flowers is called cross-pollination

The wind can also carry pollen from one flower to another

FRUIT AND SEEDS

When grains of pollen reach the stigma, they combine with ovules to form a seed

The union of pollen with an ovule is called fertilization

After fertlization. the flower loses its petals. The fertilized ovules become seeds and the ovary grows until it become a fruit

The ovules are fertilized

The ovary grows larger

The fruit protects the seeds

When the fruit is ripe, it falls from the plant. If the fruit falls in a place with light ,water and good soil ,the seeds can grow and become new plants

Germination takes place when a seed begins to grow into a new plant