Plants + flowers Flashcards
What are the parts of a flower?
Sepal petals stamen filament anther carpel stigma style ovary ovule nectary
What is the function of the sepal?
protects unopened flower
What is the function of petals?
brightly-coloured in insect pollinated flowers to attract insects.
What is the stamen?
male part of flower (filament+anther)
What is the function of the filament?
Positions anther to release male sex cell (pollen grain).
What is the function of the anther?
Produces + releases male sex cell (pollen grain)
What is the carpel?
female part of flower (stigma,style + ovary - containing ovule)
What is the function of the stigma?
Top of female part of flower - collects pollen grains
What is the function of the style?
Connects stigma to ovary
What is the function of the ovary?
produces female sex cell (ovum)
what is the ovule?
contains female sex cells (found in ovary)
What is the function of the nectary?
produces sugary sollution called nectar to attract insects
where is the ovule found?
in ovary
what is the male sex cells in flowers?
pollen grain
What is the felale sex cell in flowers?
ovum
NAME ADAPTATIONS FOR INSECT POLLINATED FLOWERS
PETALS -> large + colourful to attract insects
NECTAR -> present so insects visit flower + push past stamen to get to nectar
NUMBER OF POLLEN GRAINS -> moderate (insects transfer pollen grains efficiently with high chance of succesful polliation)
POLLEN GRAINS -> large + sticky (spiky) to attach to insects and be carried away
ANTHERS -> insidee flower, stiff + firmly attatched to brush against insects
STIGMA -> inside flower, sticky so pollen grains stick to it when insect pass by
NAME ADAPTATIONS FOR WIND POLLINATED FLOWERS
PETALS -> small + dull
NECTAR -> absent (no need to waste energy producing it as no need to atract insects)
NUMBER OF POLLEN GRAINS -> a lot (most pollen grains are not transferred to another flower so more produced=better chance of succesful pollination)
POLLEN GRAINS -> smooth, soft + light to be blown by wind
ANTHERS -> outside flower, loose on filameents to release pollen grains easily
STIGMA -> outside flower, feathery to catch pollen grains
How does the number of pollen grains differ from insect + wind pollinated flowers?
INSECT POLLINATED FLOWERS: produce smaller amounts of large, heavy pollen grains (often contain spikes/hooks on outside) to stick easily to insects
WIND POLLINATED FLOWERS: produce large amounts of small, light weight pollen grains (often smooth)
Where does fertilisation take place in plants?
inside the ovary when the nucleus of pollen grain fuses with the nucleus of an ovule to produce a zygote
Why is there a pollen tube
pollen has no “tail” to swim to ovary so it grows a pollen tube
Explain why different fruits have different number of seeds
Because plants have different number of ovules
