Reproduction in Flowering Plants

1. Reproduction in Flowering Plants Mrs. Zemcik Living Environment Expanded by Joe Naumann, UMSL Emphasis on Pollinators

2. Flower • Sexual reproductive structure • Produces egg and sperm • Fertilization takes place inside the flower

3. Pistil *Stigma –top of the pistil, Sticky surface for pollen to stick to *Style – connects the stigma to the ovary *Ovary –contains ovules ( eggs) Stamen *Anther –produces sperm nuclei by meiosis. Sperm nuclei are enclosed by pollen grains. *Filament – holds the anther up Female reproductive organ Male reproductive organ

4. Pollination • Transfer of mature pollen grains from the anther to the stigma -wind -insects -birds & other animals

6. Important (endangered?) Pollinators • Bees • Butterflies • Moths • Wasps • Bombyliid flies • syrphid flies • Beetles • Midges • Thrips • Ants • Green bottle flies • Bactrocera fruit flies • Bats • Birds • Hummingbirds • Honeyeaters • Sunbirds • monkeys, lemurs, possums, rodents and lizards

9. Scopa (pollen holder) of a Megachilid bee

10. Halictid bee, showing adhering pollen

11. Syrphid fly, showing some adhering pollen

12. Halictid bee

17. Pollinator population declines and conservation • In 1999 the Convention on Biological Diversity issued the São Paulo Declaration on Pollinators, recognizing the critical role that these species play in supporting and maintaining terrestrial productivity as well as the survival challenges they face due to anthropogenic change. Today pollinators are considered to be in a state of decline; some species, such as Franklin’s bumble bee (Bombus franklini) have been red-listed and are in danger of extinction.

18. Serious Problem • Declines in the health and population of pollinators pose what could be a significant threat to the integrity of biodiversity, to global food webs, and to human health. At least 80% of our world's crop species require pollination to set seed. An estimated one out of every three bites of food comes to us through the work of animal pollinators.

19. When a pollen grain lands on the stigma, it germinates and a pollen tube grows down through the style to an ovule (egg)

20. Fertilization • The sperm travels through the pollen tube to the ovule. The sperm & egg fuse forming the zygote (fertilized egg) –this grows into the plant embryo (cells grow by mitosis)

21. *Self pollination –pollen from same flower*Cross pollination – pollen from a different flower - more variation

22. The ovary and zygote (fertilized ovule) develop and ripen. *The ovule forms the seed and the ovary forms the fruit. • A fruit is a ripened ovary

23. The plant embryo uses food stored in the cotyledon of the seed until it develops leaves for photosynthesis

24. Seedling micropyle –opening in ovule where pollen tube attached, sperm enteredhilum –scar where ovule attached to ovaryradicle –embryonic root

25. Epicotyl – grows above the cotyledons and gives rise to the leaves. Hypocotyl –below the point of attachment of the cotyledon, develops into the stem.

26. Seed coat Hypocotyl Epicotyl Cotyledons Endosperm Seed coat Epicotyl Hypocotyl Cotyledon Radicle Parts of a seed • Dicot • Monocot

27. Monocot Dicot Epigeous Hypogeous Radicle Seed Germination

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