Sexual reproductionSexual reproduction
The mixing of genetic material from two The mixing of genetic material from two parents to produce offspringparents to produce offspring
Offspring are genetically different from Offspring are genetically different from parentsparents
PlantsPlants
Flowers are the sexual Flowers are the sexual reproductive structures reproductive structures in plantsin plants
Lily flowerLily flower
Ecological Ecological strategy:strategy:
Insect pollinated Insect pollinated flower targeting flower targeting bees in bees in particularparticular
Lily advantagesLily advantages
The reward and The reward and display make it display make it very likely that very likely that pollen from one pollen from one lily plant will lily plant will reach another lily reach another lily plantplant
Lily flowerLily flower
Draw flower, Draw flower, note projections note projections and markings on and markings on petals.petals.
Lily flowerLily flower
Stigma protrudes in Stigma protrudes in front of stamens so front of stamens so insect touches stigma insect touches stigma and deposits pollen and deposits pollen from another flower from another flower first!first!
Adaptations for pollinatorAdaptations for pollinator
Spikes on petals force Spikes on petals force pollinator past anthers pollinator past anthers on way to nectaryon way to nectary
Adaptations for pollinatorAdaptations for pollinator
Stigma is above anthers Stigma is above anthers so pollinator deposits so pollinator deposits pollen from another pollen from another flower before it gets flower before it gets pollen from this flowerpollen from this flower
Adaptations for pollinatorAdaptations for pollinator
Anthers are large so Anthers are large so pollen eating bees won’t pollen eating bees won’t destroy them, enough destroy them, enough pollen for bee and cross pollen for bee and cross pollinationpollination
Adaptations for pollinatorAdaptations for pollinator
Highly scented nectar Highly scented nectar because bees have a because bees have a good sense of smell.good sense of smell.
The flower at the right The flower at the right shows how UV shows how UV markings may guide markings may guide insect to nectary past insect to nectary past anthersanthers
disadvantagesdisadvantages
Huge energy cost (nectar and showy flower)Huge energy cost (nectar and showy flower) Insects can’t fly in bad weatherInsects can’t fly in bad weather Relies mainly on bees so if they become Relies mainly on bees so if they become
extinct then no cross pollination.extinct then no cross pollination.
Adaptations for environmentAdaptations for environment
Grow in sheltered environmentsGrow in sheltered environments Bloom in warm season spring or summerBloom in warm season spring or summer
Petals won’t get ruined by windPetals won’t get ruined by wind Cold blooded insects need warmth to flyCold blooded insects need warmth to fly Bees can’t fly in windy weather, bad weatherBees can’t fly in windy weather, bad weather Longer days for more time to pollinateLonger days for more time to pollinate
Your turn - QuestionsYour turn - Questions Describe the difference in function between the sepals and the Describe the difference in function between the sepals and the
petals.petals. The Stamen is the male reproductive structure consisting of The Stamen is the male reproductive structure consisting of
the anther and the filament, Describe how the pollen in the the anther and the filament, Describe how the pollen in the anther may get distributed.anther may get distributed.
Describe two ways a flower encourages cross pollination from Describe two ways a flower encourages cross pollination from a bee or bird.a bee or bird.
Describe why there is some distance between the stigma and Describe why there is some distance between the stigma and the ovary.the ovary.
Name some adaptations angiosperms have made to increase Name some adaptations angiosperms have made to increase their chance of survival.their chance of survival.
Name some disadvantages of the way angiosperms reproduce.Name some disadvantages of the way angiosperms reproduce.
AnswersAnswers
The sepals protect the young flower bud The sepals protect the young flower bud whereas the petals are to attract pollinators.whereas the petals are to attract pollinators.
Wind blows pollen from the flowers anther to Wind blows pollen from the flowers anther to other flowers stigma. other flowers stigma.
Bees or other animals such as birds collect Bees or other animals such as birds collect nectar and in the process transfer pollen to nectar and in the process transfer pollen to other plants.other plants.
The nectar in flowers smell good to attract The nectar in flowers smell good to attract animals that assist in cross pollinationanimals that assist in cross pollination
Answers-Adaptations Answers-Adaptations
Spikes on petals force pollinator past anthers on way Spikes on petals force pollinator past anthers on way to nectary.to nectary.
Stigma is above anthers so pollinator deposits pollen Stigma is above anthers so pollinator deposits pollen from another flower before it gets pollen from this from another flower before it gets pollen from this flowerflower
Anthers are large so pollen eating bees won’t destroy Anthers are large so pollen eating bees won’t destroy them, enough pollen for bee and cross pollinationthem, enough pollen for bee and cross pollination
Highly scented nectar because bees have a good sense Highly scented nectar because bees have a good sense of smellof smell
The flower has UV markings that guide the insect to The flower has UV markings that guide the insect to the nectary past the anthersthe nectary past the anthers
Pollen is spikey to stick to insect hairsPollen is spikey to stick to insect hairs
Answers cont..Answers cont..
The bees love nectar so encourage them to The bees love nectar so encourage them to come back to the flower and pollinate it and come back to the flower and pollinate it and other flowers.other flowers.
The stigma needs to be up high so it can be The stigma needs to be up high so it can be pollinated and the ovary needs to be pollinated and the ovary needs to be somewhere less exposed so that it can be somewhere less exposed so that it can be protected.protected.
Answers-DisadvantagesAnswers-Disadvantages
Huge energy cost (nectar and showy flower)Huge energy cost (nectar and showy flower) Insects can’t fly in bad weatherInsects can’t fly in bad weather Relies mainly on bees so if they become Relies mainly on bees so if they become
extinct then no cross pollination.extinct then no cross pollination.
Advantages, disadvantages + niche
Advantages Disadvantages Other / Niche
Gametes separate. Targeted pollination allowing high number of gametes produced to fertilise.
High energy adaptations. Bees cant fly in bad weather (extinction?).
Blooms seasonally, in sheltered environments. Pollen sticky and spikey.
Smell and UV, Wind and pollinators required.
Dominant sporophyte life cycle
Not dependant on gametophyte for survival
Nourishing zygote Zygote is protected by the plant. Seed made to provide energy for young zygote.
Pollen tube required for fertilisation. Energy required to make seed.
Can withstand harsh environments as seed can provide nutrients.
Vascular tissue Sporophyte can survive dry periods
Can survive in variety of environments
Seeds Can withstand harsh conditions before germinating when more favourable.
Lots of energy needed to make seeds.
Can grow in variety of environments