Angiosperms Flashcards
What are the non reproductive flower parts?
Receptacle, sepals and petals
What is the receptacle
The base where the petals, ovary and sepals are attached
What is sepals
They are green and they enclose and protect the developing flower
What are petals
They are brightly coloured and scented to attract insects, bats and birds
What are the female reproductive structures
The pistil, stigma and style
What is the pistil
Consists of an ovary, with an upright extension, the style, on the top of which rests the stigma
What is the stigma
Captures and traps the pollen with a sticky or hairy substance
What is the style
Allows the pollen tube to grow down to the ovule carrying the sperm nuclei
What is the ovary
The ovary encloses and surrounds one or more ovules. Each ovule contains a megasporangium.
What are the male reproductive parts
Anther and filament and together the anther and filament are called the stamen
What is the anther
Their cells undergo meiosis to produce micro spores. Each microspore undergoes mitosis to become a pollen grain, containing two sperm nuclei
What is the filament
Filament is the stalk that supports the anther
How does pollen get transferred
Pollen grains produced by meiosis of micro spores, are transferred by insects, birds or wind from the anther to the sticky stigma
What needs to happen before fertilization can take place
Before fertilization can take place the pollen grain must germinate to produce a pollen tube which grows down the style and into the ovule within the ovary
What happens when double fertilization takes place
One sperm nuclei (N) fuses with the polar nuclei(N+N) producing an endosperm (3N) which provides nutrients for the developing embryo. The other sperm nuclei fuses with the egg producing a zygote which develops into a multicellular embryo in a seed
