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reproduction in plants :red_flag::+1: - Coggle Diagram
reproduction in plants :red_flag::+1:
How do plants reproduce
plants that have reproductive structure are involved in sexual reproduction
plants reproduce by seeds, spores or other parts
Plants reproduce to ensure
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of their own kind :!?:
How do flowering plants reproduce
Reproduction from Seeds
flowering plants carry out sexual reproduction from seeds
adult plants produce flowers once
pollinated,
female reproductive cells in ovules are
fertilised
by male reproductive cells found in pollen grain, flowers become fruits that contain seeds when
dispersed
, seed
germinates
to a new plant
life cycle repeats when adult start bearing flowers
Structure of a flower (P64 Picture) :pencil2:
some have male and female reproductive parts on separate flowers
For example, cucumber, maize and watermelon
Functions of different flower parts (P65 Table) :pencil2:
filament hold anthers up
stigma receives pollen grains
style connects stigma to ovary
ovary protect ovule after fertilisation
ovule become seeds after fertilisation
petals to attract pollinators like birds and insects
anther contains pollen grain stored in pollen sacs
most plants have both male and female reproductive parts on a single flower
For example,hibiscus, morning glory and tomato
A few types of plants have male and female parts on several plants
For example, asparagus
Pollination
pollination occurs when pollen grains transferred from the anther of one flower to the stigma of the same flower or another flower of the same kind.
wind, birds and insects help pollinate
insect pollinated flowers are large, sweet scented and brightly coloured to attract insects
stigma is sticky and anther is inside plant
anthers do not hang out of the flowers
Example: rose
When an insect visits a flower to feed on the nectar, pollen grains from the anther stick to the insects' hairy bdy
The pollen grains are brushed off onto the stigma of the same flower or another flower that the insect visits
wind pollinated flowers are dull and small, anther is out of flower for pollen grain to be shaken free easily by the wind, stigma is large and feathery
Example:grass
The filament sways in the wind and pollen grains are shaken free
The pollen grains are carried by the wind and land on the stigma on the stigma of another flower
Fertilisation
fertilisation is when a male reproductive cell fuses with a female reproductive cell
During pollination, pollen grans are transferred to the stigma
Each pollen grain produces a pollen tube, the male reproductive cells are found inside the tip of it.
The pollen tube enters the ovule that contains an egg cell
Formation of Fruits and Seeds
when ovary is ready to release seeds, its ripened
ovules to seeds, ovaries to fruits
After fertilisation, most of the flower parts usually wither and drop off, except the ovary
dispersal of fruits and seeds
Why disperse?
needed to prevent overcrowding for competition of light, water, nutrients, and space
So that they can grow in a new and more favourable place
as plants cannot move about, their fruits and seeds have special characteristics and/or adaptations to help their dispersal, they need
animals, wind, water or explosive action
to disperse the seeds
fruits dispersed by animals are sweet, brightly coloured and have hooks or stiff hair
Example: Mango
dispersed by wind are small and light, have parachute like structures to fly
Example: Angsana, lalang
dispersed by water have fibrous husks and stay afloat in water
Example: coconut
Dispersed by explosive action/splitting: fruit walls split open with sudden force and shooting out when ripe in all directions
Example: balsam and beans
germination
first stage of development, they can only germinate when conditions are favourable
will germinate if get enough oxygen, water and warmth
A seed does not need light to germinate
Remain dormant until the conditions are favourable for germination
Growth of a seed after germination
root grows first. It is the first stage of the life cycle
have seed leaves to store energy for germination
shoot appears after root
when first leave opens, it can photosynthesis
allows more water to be absorbed
how do non flowering plants reproduce
reproduce by spores instead of seeds
spore bags contain spores
Spores are tiny and can only be examined by microscope, dispersed by wind because they are light
like seeds, will germinate when conditions are favourable
For example: fern
spores are found in the spore bags located on the underside of mature leaves
non flowering plant's spores are found in the spore bags located at the end of the stalk