Topic 4 - Plant Growth and Reproduction Flashcards
Sexual reproduction
a process involving the fusion of the nuclei of two gametes to form a zygote and the production of offspring that are genetically different from each other
Anther
Produces the male gametes (pollen grains)
Filament
Allows positioning of the anther so that pollen grains can be distributed
Stigma
Where the pollen grains attach to, often sticky
Style
Positions stigma to accept pollen grains. The pollen grain tube grows through this structure
Ovary
Contains the egg, will house the fertilised egg and eventually develop into a fruit
Nectar
Sweet sugary substance that attracts insects
Petal
Colourful structure that sometimes have special markings. Used to attract insects for pollination.
Sepal
Green leaf-like structures that protect the flower in the bud
Pollination
The transfer of pollen from the anther to the stigma of a plant
Insect pollinated flower adaptations
- nectar and scent
- brightly coloured petals
- anthers positioned to rub pollen onto insects
- sticky stigma to collect pollen
Wind pollinated flower adaptations
- large volume of pollen grains that are small and light
- small, green petals (no need to attract insects)
- feathery stigma to catch pollen carried on the wind
- anthers are exposed to wind so that pollen can easily be carried away
Testa
tough seed coat
Micropyle
hole made by pollen tube
Cotyledon
food store
