UNIT 16: REPRODUCTION IN PLANTS
Asexual reproduction: process resulting in production of genetically identical
offspring from 1 parent
Advantages Disadvantages
Population can increase rapidly Does not lead to variation in a
Can exploit a suitable habitat population
quickly The species may only be suited one
Only 1 parent needed habitat
Rapid colonisation of favourable Diseases, environmental changes
environment may affect all the individuals
Sexual reproduction: a process involving the fusion of the nuclei of 2 gametes
(fertilisation) to form a zygote (diploid) and the production of offspring that are
genetically different from each other
Advantages Disadvantages
Introduces variation into a Time and energy are needed to find
population a mate
The species can adapt to new Not possible for an isolated
environment individual
A disease is less likely to affect all 2 parents are needed
Sepal: protects the flower
Petal: attracts insect through bright colours
Anther: contains male gamete in pollen
Stigma: catch pollen
Ovary: contains the ovules
Pollination: transfer of pollen grains from
male part of plant (anther or stamen) to
female part (stigma)
Self- pollination: the transfer of pollen grains from an anther of a flower to the
stigma of the same flower or onto the stigma of another flower on the same plant
Cross-pollination: the transfer of pollen grains from an anther of a flower to the
stigma of a flower on a different plant of the same species
Wind-pollinated Insect-pollinated
Petals Small (or absent) Large (to act as landing platform)
Dull Colourful
Not scented Nectar attracts insect
Pollen Small, light, smooth Larger, heavy, sticky/spiky
grains Vast quantities Smaller quantities
Anthers Held outside the flower Protected within flower
Relatively large Relatively small
Stigmas Large surface area Smaller surface area
Outside the flower Inside flower
Self-pollination Cross-pollination
Decrease the variation in the Increase variation in offspring
Asexual reproduction: process resulting in production of genetically identical
offspring from 1 parent
Advantages Disadvantages
Population can increase rapidly Does not lead to variation in a
Can exploit a suitable habitat population
quickly The species may only be suited one
Only 1 parent needed habitat
Rapid colonisation of favourable Diseases, environmental changes
environment may affect all the individuals
Sexual reproduction: a process involving the fusion of the nuclei of 2 gametes
(fertilisation) to form a zygote (diploid) and the production of offspring that are
genetically different from each other
Advantages Disadvantages
Introduces variation into a Time and energy are needed to find
population a mate
The species can adapt to new Not possible for an isolated
environment individual
A disease is less likely to affect all 2 parents are needed
Sepal: protects the flower
Petal: attracts insect through bright colours
Anther: contains male gamete in pollen
Stigma: catch pollen
Ovary: contains the ovules
Pollination: transfer of pollen grains from
male part of plant (anther or stamen) to
female part (stigma)
Self- pollination: the transfer of pollen grains from an anther of a flower to the
stigma of the same flower or onto the stigma of another flower on the same plant
Cross-pollination: the transfer of pollen grains from an anther of a flower to the
stigma of a flower on a different plant of the same species
Wind-pollinated Insect-pollinated
Petals Small (or absent) Large (to act as landing platform)
Dull Colourful
Not scented Nectar attracts insect
Pollen Small, light, smooth Larger, heavy, sticky/spiky
grains Vast quantities Smaller quantities
Anthers Held outside the flower Protected within flower
Relatively large Relatively small
Stigmas Large surface area Smaller surface area
Outside the flower Inside flower
Self-pollination Cross-pollination
Decrease the variation in the Increase variation in offspring
