Reproduction in flowering plants Flashcards
asexual reproduction (vegetative propagation)
- requires one parent
- offspring genetically identical to parent
- does not require gametes - offspring forms through mitosis
- no fertilisation takes place
sexual reproduction
- requires two parents
- offspring is a genetic combination between two parents
- requires formation of gametes
- fertilisation has to take place
- advantages of asexual reproduction
- one organism can form a whole population
- requires less energy to reproduce
- each offspring is a genetic copy of the parent
- advantages of asexual reproduction
- offspring can be formed in shorter amount of time
- rapid population growth
- less likely to become extinct
disadvantages of asexual reproduction
- no genetic variation in offspring
- therefore less adaptable to changing environment
advantages of sexual reproduction
- more adaptability to change in environments
- more variation
- new varieties can form
disadvantages of sexual reproduction
- takes longer to produce offspring
- requires a lot of energy
- requires two individuals
- greater chance for extinction
pollination
transfer of male pollen grain from male anther to female stigma
stigma - sticky
ensures that male pollen can attach to female part of plant
style
connective tube
ovary
- 1st place where meiosis takes place
- ovary develops into fruit
ovule
egg cells that plant produces (haploid)
-fertilised ovules develop into seeds
carpel/pistil
- stigma
- style
- ovary
stamen
- anther
- filament
anther
- haploid pollen grains
- 2nd part where meiosis takes place
- produces pollen
filament
keeps anther in place (attaches to sepal)
petals
attract pollinators (birds or insects)
fertilisation
- takes place in ovary
- male gamete (sperm) and a female gamete (egg cell) fuse to form a zygote, which will develop into a new individual
after fertilisation
pollen tube
opening of style
micropyle
endosperm
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self-pollination
pollinates itself
pollen from the same flower
cross pollination
pollen from different flower
more variation
- adaptation for wind pollination
dull
scentless flowers
reduced petals
- adaptation for wind pollination
- anthers hang outside
- pollen blown by wind
- feathery stigma (easily trap pollen)
- adaptation for insect-pollinated flowers
- pollen has barbs for hooking onto insect fur
- sticky stigma to collect pollen
- anthers positioned to rub pollen onto insects
- bees/butterfly pollination
- bright colour
- nectaries
- scent
- bees/butterfly pollination
- they sip nectar
- get pollen on coats
- transfer pollen from flower to flower
bird pollination
- nectaries
- bright colours
- tube-like flowers
moth pollination
- white petals
- open at night
fly pollination
-rank odor
flesh coloured petals
fruit formation
- flower (after fertilisation)
- petals wither
- ovary begins to swell
- petals drop off
- seeds develop inside fruit
- fruit grows bigger (ovary then grows bigger until it becomes a fruit)
fruit formation
ovary development fruit set cell division cell expansion ripening
- seed banks
- stores seeds as a source for planting in case seed reserves elsewhere are destroyed
- type of gene bank
- seed banks
- storing seeds also guards against catastrophic events like natural disasters, outbreaks of disease or war
- unlike seed libraries or seed swaps that encourage frequent reuse and sharing of seeds, seed banks are not typically open to the public
