Plants and Society

Plant Sexual Reproduction

Flowers

Reproductive part of plant.

Made-up of 4 floral organs. Note : organ=many tissues performing 1 function eg fruit, leaf.

 

Male structures

Stamen.

Female structures:

Pistil.

     

Flowers

Monocts

Dicots 

Floral organs:  

Complete flower: .

Incomplete flower:

Perfect flower:

Imperfect flower:  o      

           

Monecious:  

Corn: pollen from flowers at top fall onto stigma below. Fertilized ovaries become kernels of corn.

Dioecious:  

Holly (females have berries); Gingko (female plants outlawed, the fruit stinks!!!).

 

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Pollination

Pollination is the transfer of pollen from an anther to a stigma.

 

Pollination Facts.

A single stamen of corn contains 2,000-2,500 pollen grains.

1 healthy ragweed plant can release one billion pollen grains

Flowers pollinated by birds generally produce lots of nectar.

Fertilization

After pollination, the pollen grain sends a tube down the style to the ovary.

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Seeds

End product of sexual reproduction of flowering plants.

Each seed contains: embryonic plant, endosperm & a seed coat.

Seed germination and development

Fruits