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BOT3015L Biology of Flowering Plants: Reproduction Flowers and Pollination Presentation created by Danielle Sherdan All photos from Raven et al. Biology.

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Presentation on theme: "BOT3015L Biology of Flowering Plants: Reproduction Flowers and Pollination Presentation created by Danielle Sherdan All photos from Raven et al. Biology."— Presentation transcript:

1 BOT3015L Biology of Flowering Plants: Reproduction Flowers and Pollination Presentation created by Danielle Sherdan All photos from Raven et al. Biology of Plants except when otherwise noted

2 Today Introducing angiosperms, flower structure and function Pollination Evolutionary trends in floral structure Inflorescences Monocots and dicots Introducing angiosperms, flower structure and function Pollination Evolutionary trends in floral structure Inflorescences Monocots and dicots

3 Saguaro cactus Apple Cherry Flowers are distinguishing characteristics of angiosperms All fruits come from flowers Sunflowers Cattleya orchid Angion=vessel Sperma=seed Angiosperms have seeds contained in a vessel (developing ovary)

4 Flowers What are the functions of flowers? How are these functions important for the survival of species? Honeysuckle

5 Alternation of Generations generalized plant life cycle In angiosperms, gametophytes are borne within the reproductive structures of the flower; thus flowers are important when discussing evolution of angiosperms

6 Flower dissection a guided tour Notice the arrangement of the floral parts

7 Arrangements of floral organs Spiral arrangement of floral organs. Stamens Sepals Petals Carpels Arrangement of floral organs in whorls. Primitive Advanced

8 Flower dissection a guided tour Note that the petals are inserted after the sepals What are the functions of these floral parts?

9 Flower dissection a guided tour stamen What are the functions of the stamens? Hint: collectively, the stamens are termed the androecium (andro=male, ecium=house). We will discuss the microgametophyte next week

10 The stamens of most grasses (left) and the paper birch (right) are easily blown by wind. The flowers of most grasses do not have showy petals, why?

11 Flower dissection a guided tour stamen We will discuss more about the megagametophyte next week Ovary, ovules (within ovary), style, and stigma comprise the carpel (megasporophyll) What are the functions of the carpel?

12 Alternation of Generations generalized plant life cycle In angiosperms, gametophytes are born within the reproductive structures of the flower; thus flowers are important when discussing evolution of angiosperms Requires pollination

13 Today Introducing angiosperms, flower structure and function Pollination Evolutionary trends in floral structure Inflorescences Monocots and dicots

14 Pollination In angiosperms, movement of the microgametophyte (pollen grain) to the megagametophyte in the ovule of the carpel How does a sessile organism, the microgametophyte in the case of angiosperms move? Vectors In the following discussion, notice the co-evolution of flowers and their biotic vectors

15 Some plants make big investments in attracting animal pollination vectors Nectar Notice the pollen on the hummingbirds forehead and the stigma that touches it as he feeds

16 Some plants make big investments in attracting animal pollination vectors Pollen Seat bee gathering pollen from the stamens of a cactus flower

17 Some plants make big investments in attracting animal pollination vectors Cypridium sp. Koning, Ross E Pollination Adaptations. Plant Physiology Information Website. ( ). Drugs (Intoxication)

18 Some plants make big investments in attracting animal pollination vectors Ophrys bécasse Charente photonature-pvd.chez.tiscali.fr/ ophrys.htm Prospect of Sex (pseudocopulation) Ophrys speculum

19 Plants that rely on wind make big investments in pollen grass birch Notice the stigmas that fan out to easily catch pollen

20 Pollination Biology movie

21 Today Introducing angiosperms, flower structure and function Pollination Evolutionary trends in floral structure Inflorescences Monocots and dicots

22 Evolutionary Trends in Floral Structure 1. Reduction in number of parts

23 Perfect and Imperfect flowers From Outlaw lecture

24 Evolutionary Trends in Floral Structure 1.Reduction in number of parts 3. Fusion of organs 2. Cyclic arrangement (vs. spiral)

25 Fusion of floral parts Angel trumpet has fused petals that form a floral tube Outlaw lecture notes

26 Fusion of organs Notice the stamens fused to the carpel of this hibiscus flower Danielle Sherdan NE Tallahassee, FL

27 Fusion of floral parts Superior and Inferior ovaries Superior ovary (primitive)note typical appearance of order of insertion of floral parts. Superior, parts still appear to arise in normal order. Inferior, floral tube fused to ovary wall, making ovary appear to arise below other floral parts. Ancestral Derived

28 Evolutionary Trends in Floral Structure 1.Reduction in number of parts 3. Fusion of organs 2. Cyclic arrangement (vs. spiral) 4. Away from marginal placentation

29 Placentation Parietal Axile Free central Primitive Advanced Marginal Seeds attached to margin of single carpel Fusion of carpels The ovary develops into the fruit, another distinguishing characteristic of angiosperms Within each ovule, double fertilization, a distinguishing characteristic of angiosperms, produces the zygote and endosperm.

30 Evolutionary Trends in Floral Structure 1.Reduction in number of parts 3. Fusion of organs 2. Cyclic arrangement (vs. spiral) 4. Away from marginal placentation 5. Away from regularity e.g. toward bilateral symmetry over radial symmetry

31 Bilateral and Radial Symmetry This orchid, an advanced monocot, displays bilateral symmetry This wintergreen displays radial symmetry, which is primitive, but fused carpels, which is derived

32 Today Introducing angiosperms, flower structure and function Pollination Evolutionary trends in floral structure Inflorescences Monocots and dicots

33 Inflorescences Groups of flowers in particular arrangements Lupine Some examples

34 Inflorescences Groups of flowers in particular arrangements What is a fitness advantage of having inflorescences? What is a fitness disadvantage of having inflorescences?

35 Inflorescences Groups of flowers in particular arrangements Notice that these composites display many evolutionarily advanced characteristics

36 Today Introducing angiosperms, flower structure and function Pollination Evolutionary trends in floral structure Inflorescences Monocots and dicots

37 Monocots and Dicots the two major groups of angiosperms Monocots and dicots have several differentiating characteristics Number of cotyledons Function of cotyledons Seed structure at maturity Number of flower parts Root structure Secondary growth in shoot Arrangement of vascular bundles Leaf venation Observe today In your lab notebook, create a table to contrast these traits in monocots and dicots

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