T4- Structre of a Flower/ Pollination Flashcards
Anther def.
Where the pollen grains are made and found. These contain the male gametes (sex cells).
Filament Def.
The structure that holds up the anther
Petals def
These provide some protection to the structures inside the flower. Can be large and colourful to attract insects.
Stigma
Where a pollen grain lands during pollination
style
This links the stigma to the ovary. A pollen tube can grow through here to allow fertilisation to take place.
ovaries
The ovules are found inside this structure
Ovule
The female gamete (sex cell)
What is the first part of sexual reproduction in plants?
pollination. This is the transfer of pollen from the anther to the sigma.
What are the 2 ways pollination can occur?
insect and wind
what is the job of pollen barbs and sticky stigma?
the pollen has barbs for hooking onto insect fur.
the sticky stigma is to collect pollen.
Why do wind-pollinated flowers have a different structure from insect-pollinated flowers?
they do not have to attract insects to them but they do need to be exposed to the wind.
What is the job of the exposed anthers and the feathery stigmas on the wind-pollinated flowers?
anthers are exposed to the wind so that pollen can easily be blown away.
stigma is feathery to catch pollen carried on the wind.
What happens after pollination?
After pollination, a pollen tube grows from the pollen grain down through the style to the ovule. This allows the male gamete from the pollen grain to reach the female gamete in the ovule.
Why are enzymes released?
enzymes are released that break down the stile so the pollen can pass through.
what do ovaries develop into?
The ovary develops into a fruit.
What do ovules develop into?
The ovules develop into seeds.
What does Cotyledon contain?
contains starch (food) - for the embryo
When starch breaks down what does it become?
Starch breaks down to become glucose, the glucose is used for respiration and is energy for when the plant has to grow.
Why do seeds need to be dispersed away from the parent plant?
in order to reduce competition for space, light, nutrients and water.
what are the 4 ways seeds can disperse?
Seeds can be dispersed by: Wind Water Mechanical Animals
What happens after fertilisation in plants?
After fertilisation, the petals, stamen and sepals fall off.
The ovule turns into a seed and the fertilised egg inside develops
into an embryo plant.
Water leaves the seed so that it dehydrates and becomes dormant.
What is Germination?
the sprouting of the plumule and radicle of a seed.
What needs to happens for germination to occur?
For germination to occur, water enters the seed and activates enzymes.
The water also softens the testa to allow it to split.
What does the plant do whilst the food whilst germinating?
Whilst germinating, the plant uses food stores in the cotyledon to provide energy for growth.
