society for conservation biology auburn university chapter check us out on facebook when?tuesday...

Society for Conservation BiologySociety for Conservation BiologyAuburn University ChapterAuburn University Chapter

Check us out on Facebook

WHEN?

TUESDAYTUESDAY Mar. 3

6:00-7:00 PM

Guest Speaker: Dr. David SteenGuest Speaker: Dr. David Steen““Road mortality and freshwater turtle Road mortality and freshwater turtle

conservation in North Americaconservation 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 knownto form canopyroots

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 CycleSeed plants + ferns: major body = _______

Who am I? (Lab 3)Epiphyte fernSite 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 seedWhat’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 SagittariaPistillate flowers of Sagittaria

Floral variation• Pistillate & carpellate .: dioecious (MUST

outcross)• Monoecious: both sexes

Cones!

Floral variation• Ex. dioecious species: Persimmon

(Diospyros virginiana)

Persimmon fruits

Staminateflower

Pistillateflower

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.

diskflowers

ray flowers

Floral variation• Who am I? (Lab #1)

– Inflorescence: white structures = bracts

Inflorescence Closeup showing individualgreenish 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

CaryaA grass

Terms• Biotic pollination: pollen carried by animal--

90% flowering plants– Floral visitor: visits – Pollinator: deposits

Pollination as MutualismMutualism (+,+) interaction

– Plant gets– Animal gets

Reward?

Animal Rewards• Pollen: hi • Also lipids,

Renewable…