lab 04

Lab 4: Angiosperms: Evolution of the Flower and Fruit: 

Lab 4: Angiosperms: Evolution of the Flower and Fruit Tasks to prep for next week Angiosperms: Phylum Anthophyta Traditional Classes: Monocotyledonae and Dicotyledonae Flowers and Fruits Life Cycle Tasks

Tasks to prep for next week…: 

Tasks to prep for next week… Seed germination roll (Page 5.9) paper towel on INSIDE seed on paper towel paper towel bottom sticks out to wick up water

Tasks to prep for next week…: 

Tasks to prep for next week… Leaf abscission use a razor blade to remove a pair of leaf blades from Coleus plant (leave petioles intact!) use wooden applicator to put lanolin paste (A) on one petiole tip (do not label) use wooden applicator to put lanolin paste with NAA (B) on the other petiole tip (label using white paper ring)

Angiosperms: Phylum Anthophyta: 

Angiosperms: Phylum Anthophyta Angiosperms – “seed in a vessel” at time of pollination, ovule is enclosed in sporophyte tissue (ovary) ovary later develops into fruit that encloses the seed other structures may also contribute to the fruit (“accessory structures”) flowers and fruits are unique to angiosperms

Angiosperms: Phylum Anthophyta: 

Angiosperms: Phylum Anthophyta one phylum = Anthophyta = “flowering plants” two traditional classes: Monocotyledonae (monocots) Dicotyledonae (dicots) new version (eudicots) splits off some problematic groups; don’t worry about eudicots for lab

Angiosperms: Phylum Anthophyta: 

Angiosperms: Phylum Anthophyta monocots – some key characteristics one cotyledon (seed leaf) flower parts typically multiples of 3 leaves with parallel venation of vascular tissue dicots – some key characteristics two cotyledons flower parts typically multiples of 4 or 5 leaves with netlike venation of vascular tissue

Slide7: 

Flowers

Flowers: 

Flowers flower parts attached to receptacle in four whorls; from outside in: calyx – sepals corolla – petals androecium – stamens gynoecium – carpels

Slide9: 

complete – calyx + corolla + androecium + gynoecium incomplete – one or more whorls absent perfect – has both androecium and gynoecium imperfect – missing either androecium or gynoecium loss of whorls is a derived characteristic Flowers

Slide10: 

separate floral parts is the ancestral condition; fused parts is a derived characteristic connation – fusing within a whorl adnation – fusing between whorls (for example, sepals and petals fused together) CORRECTION to lab manual: page 4.6 – every “adnation” should be “connation” and “connation” should be “adnation” Flowers

Slide11: 

symmetry: ancestral form is “regular” or radial symmetry (actinomorphic) Flowers

Slide12: 

derived form is “irregular” or bilaterally symmetry (zygomorphic) Flowers

Fruits: 

Fruits typically formed from ovary wall (pericarp); may be divided into exocarp (outer wall) mesocarp endocarp (inner wall, next to seed)

Fruits: 

Fruits if material outside of ovary is included, the fruit is an “accessory fruit” includes material derived from receptacle and/or floral tube example: apple

Fruits: 

Fruits three groups: simple (derived from one pistil) aggregate (from separate carpels on one flower) multiple (from multiple flowers)

Fruits: 

Fruits also divided by: pericarp fleshy or dry at maturity dry subdivided based on splitting at maturity dehiscent – splits open at maturity indehiscent – doesn’t split

Angiosperm Life Cycle: 

Angiosperm Life Cycle still alternation of generations…

Alternation of Generation (Sporic Meiosis): 

Alternation of Generation (Sporic Meiosis) 2N 2N 1N 1N 1N mitosis mitosis gametes (zygote) spores gametophyte sporophyte diploid (2N) generation haploid (1N) generation

Angiosperm Life Cycle: 

Angiosperm Life Cycle see pages 4.8-4.9 see also class webpage key new terms to point out (beyond flower and fruit terms already covered):

Angiosperm Life Cycle: 

Angiosperm Life Cycle embryo sac – mature female gametophyte (7 cells, 8 nuclei)

Angiosperm Life Cycle: 

Angiosperm Life Cycle double fertilization – one sperm fertilizes egg to make zygote; other fertilizes polar bodies to make 3N endosperm (used for food)

Task 1: The Flower: 

Task 1: The Flower flower structure examine Alstromeria flowers (note change from lab manual); compare to Figure 4-1 dissect and examine as indicated on page 4.5 examine specimens and fill out Table 4-1 for the following: Alstroemeria Snapdragon Carnation Lily Rose

Task 1: The Flower: 

Task 1: The Flower anthers and pollen development examine transparencies examine pollen grains on slide “Lilium anthers”

Task 1: The Flower: 

Task 1: The Flower germination of pollen this will be a demo on the TV also, examine slide of mixed pollen grains ovules and embryo development examine slide of lily ovary examine color transparencies

Task 2: The Fruit: 

Task 2: The Fruit examination of fruit types examine the fruits on demonstration record at least one example of each type in Table 4-3 except for “other accessory fruit” and “other” use the dichotomous key (Table 4-2) to help as much as possible, but also take advantage of the drawings (Figures 4-6, 4-7, 4-8, 4-9)

Slide26: 

TODAY YOU WILL HAVE AN EXIT ACTIVITY