Society for Conservation Biology Auburn University Chapter Check us out on Facebook WHEN?TUESDAY Mar. 3 6:00-7:00 PM Guest Speaker: Dr. David Steen “Road mortality and freshwater turtle conservation in North America” Also: Info on Tigers 4 Tigers plans for spring semester! WHERE? 112 Rouse Life Sciences

Ch. 7: Plant Growth and Reproduction

Plant Growth Includes: –phenology –location of overwintering buds (criterion for major subdivisions) Fig. 7.2

Plant Growth Main Raunkiaer categories (7): –7) Epiphyte: germinates & grows on plants Lab #3: Who am I??

Epiphyte Focus Effect on host: –Negligible (commensalism: one benefits & other unaffected) –(+,0) (epiphyte, host)

Epiphyte Focus Effect on host: –Positive. Canopy roots (host): roots –Mutualism: (+,+) Trees known to form canopy roots

Parasitic Epiphytes Negative: Parasites. Tap Parasitism. (+,-) (epiphyte, host)

Parasitic Epiphytes Holoparasites: No chlorophyll. Haustoria (modified roots) penetrate Ex, dodder (Cuscuta) “Witches hair” “Love vine”

Parasitic Epiphytes Hemiparasites: Chlorophyll-- water & nutrients from Ex, Who am I? (Lab #3)

Plant Reproduction 2 main types Two main types…..

Plant Reproduction Sexual reproduction: genetically varying offspring (via meiosis & fertilization)

Plant Reproduction Asexual reproduction: genetically identical offspring (involves mitosis) –Ex, clonal growth (discussed)

Plant Reproduction Agamospermy: seeds asexual (CLONES) –Exs: Taraxacum (dandelion), some Rubus

Plant Reproduction Asexual reproduction: genetically identical offspring Sexual reproduction: genetically varying offspring (via meiosis and fertilization )

Plant Reproduction Meiosis: reduction division 2N to 1N

Plant Reproduction Fertilization: gametes (egg+sperm) form 1N to 2N Human example….

Plant Life Cycle Life cycle: Involves 1) meiosis, 2) fertilization, 3) haploid cells, 4) diploid cells

Plant Life Cycle Sporic meiosis: 2 bodies, 1 cycle: alternation of generations Sporophyte 2N, gametophyte 1N

Plant Life Cycle Gametophyte (1N): gametes BY MITOSIS Fertilization: zygote (2N) Start

Plant Life Cycle Zygote to sporophyte (2N): mitosis Sporophyte: spores BY MEIOSIS Spore to gametophyte: End

Plant Life Cycle Mosses: gametophyte leafy –Sporophyte on Granite outcrop lab

Plant Life Cycle Seed plants + ferns: major body = _______ Who am I? (Lab 3) Epiphyte fern Site for sori…. Lab #1? Where other “body”?

Plant Life Cycle Where gametophytes? –Seed plants: male = pollen grain Ferns

Plant Life Cycle Female gametophyte (embryo sac): inside ovule Ovules in ovary

Life Cycle Mature male gametophyte = Fertilization: sperm & egg form zygote (2N) DOUBLE fertilization!

Life Cycle Zygote: embryo in ovule Endosperm: nutritive Ovule into seed What’s a seed??

Life Cycle Seed: baby plant ( : new sporophyte) in box ( coat) with lunch ( : flowering plants)

Terms Flower parts (BIOL 1030) 4: sepals, petals, stamens, pistil(s) Carpel= Pistil here

Floral variation Fusing petals –Long-tongued/long-billed pollinators Who am I? (Lab #3) seeds

Floral variation Stamens & pistils: perfect flowers

Floral variation Some imperfect. Pistillate (pistil) or staminate (stamens) Staminate flowers of Sagittaria Pistillate flowers of Sagittaria

Floral variation Pistillate & carpellate.: dioecious (MUST outcross) Monoecious: both sexes Cones!

Floral variation Ex. dioecious species: Persimmon (Diospyros virginiana) Persimmon fruits Staminate flower Pistillate flower

Floral variation Complete flowers: all 4 parts (sepals, petals, stamens, pistil) Lack : incomplete flowers Diospyros?

Floral variation Group flowers: inflorescence –One type: head –Ex, sunflower (Asteraceae) –Ray flowers: lg. –Disk flowers sm. disk flowers ray flowers

Floral variation Who am I? (Lab #1) –Inflorescence: white structures = bracts Inflorescence Closeup showing individual greenish flowers

Pollination Why flowers vary? Many form mutualism w/ animals

Terms Pollination (flowering plants): transfer Carpel=pistil

Terms Fertilization: sperm fuses w/ egg (in ovule), makes

Pollination Abiotic: pollen carried

Wind Pollination Grasses, temperate trees (Quercus, Carya, Pinus) Not Carya A grass

Terms Biotic pollination: pollen carried by animal-- 90% flowering plants –Floral visitor: visits –Pollinator: deposits

Pollination as Mutualism Mutualism (+,+) interaction –Plant gets –Animal gets Reward?

Animal Rewards Pollen: hi Also lipids, Renewable…