plants reproduction Flashcards
Describe in order the events which occur after a plant is pollinated. Include an explanation of how a seed is formed?
The pollen tube grows out the pollen grain grows down through the style to the ovary and into the ovule. a nucleus from the male gamete moves down the tube to join with a female gamete in the ovule. the nuclei fuse together during fertilisation to make a zygote which divides by mitosis to form an embryo. the fertilised female gamete forms a seed
What are the four mechanisms for seed dispersal?
Wind
Water
Mechanical
Animals
Why do seeds needs to be dispersed away from the parent plant?
in order to reduce competition for space, light, mineral ions and water
Why does a seed become dormant?
Because of metabolic reactions
Which part of the flower develops into a seed?
The ovule
Why is it preferable for a plant to encourage cross-pollination rather than self-pollination?
Cross pollination leads to genetic variation, this means that a species is more able to adpat to change in the environment
what is the male part of the flower
The male part of the flower is called the stamen and consists of the anther and filament.
what is the female part of flower
The female part of the flower is called the carpel and consists of the stigma, style and ovary
where is the male gamete found and made
The male gamete is made in the anther and is found in the pollen grain.
where is the female gamete found and made
The female gamete is found in the ovary and is called an ovule.
insect pollination
petals - big and brightly coloured
nectary - nectary is present to produce nectar
scent - scented to attract insects
stigma - sticky for pollen to stick to
stamen - smaller and held inside the flower
wind pollination
petals - smaller or no petals, less colourful
nectary - no nectary
scent - no scent
stigma - feathery and hang outside the flower
stamen - anthers are large and hang outside the flower
