Title: Plant Reproduction II
1Plant Reproduction II
- Roses are red,
- Violets are blue,
- Some poems rhyme.
- But this one doesn't.
-
- - anonymous
2Business
- Quiz Wednesday,
- Essay Questions due Weds. Midnight, 2 pt Extra
Credit.
3 The Tree(s) of LifeKwakwakawakw
- Western Red cedar
- (Thuja plicata)
- and -
- Alaska cedar/ Yellow cedar
- (Chamaecyparis nootkatensis)
Thuja plicata
4 The Tree(s) of LifeKwakwakawakw
- Western Red cedar
- (Thuja plicata)
- and -
- Alaska cedar/ Yellow cedar
- (Chamaecyparis nootkatensis)
Chamaecyparis nootkatensis
5- "In a small clearing in the forest, a young
woman is in labour. Two women companions urge
her to pull hard on the cedar bark rope tied to a
nearby tree. The baby, born onto a newly made
cedar bark mat, cries its arrival into the
Northwest Coast world. Its cradle of firmly
woven cedar root, with a mattress and a covering
of soft-shredded cedar bark, is ready. The young
woman's husband and his uncle are on the water in
a canoe carved from a single red cedar log and
are using paddles made from lengths of yellow
cedar. Wearing a cedar bark hat, cape and skirt
to protect her from the rain and cold, the baby's
grandmother collects berries. She loads them
into a basket of cedar root and adjusts the broad
cedar tumpline across her forehead and returns
home. - The embers in the centre of the cedar house
leap into flame as the grandmother's niece adds
more wood. Smoke billows past the cedar rack
above, where small fish are hung to cure. The
young girl takes red-hot rocks from the fire with
long tongs, dips them into a small cedar box of
water to rinse off the ashes, then places the
rocks into a cedar wood cooking box to boil
water. The young girl then coils two fresh
diapers from soft-shredded cedar bark and goes to
tend a crying baby, while the child's father
prepares long, slender cedar withes to lash a
stone hammer to. With the hammer finished he uses
it to pound wedges into a cedar log to split off
a plank for a tackle box to fit in bow of his
canoe."
Hilary Stewart's Cedar tree of life to the
Northwest Coast Indians (1984)
6- Look at me friend! I come to ask for your
dress For you have pity on us For there is
nothing for which you cannot be used...For you
are really willing to give us your dress, I come
to beg you for this, Long-life maker For I am
going to make a basket for camus-roots out of you.
Kwakwakawakw prayer
7Secondary Growth
8(No Transcript)
9Today
- Spore formation,
- Gamete formation,
- Pollination,
- Fertilization,
- Germination.
10Spore Formation Study Fig 40.8
11Pollen Development(male gametophyte)
Fig 40.8
meiosis
mitosis
microspores ...meiosis yields four haploid
cells,
12Pollen Cells
Lily
Sperm
Tube Cell forms the pollen tube, Generative
cell forms two sperm (mitosis),
13Pollen
Horse Chestnut
Lily
Lily Close-up
Ragweed
- Outer wall is formed primarily of sporopollenin,
- and proteins (mating signals?),
- Form adapted for specific pollinators,
- Species specific, durable.
- Well represented in the fossil, prehistoric and
historic record, - Used for environmental and ecological studies,
- Used for forensic work.
14(No Transcript)
15Embryo Sac Development( female gametophore)
Fig 40.14
meiosis
mitosis
16Embryo Sac Development( female gametophyte)
megasporocytes
ovules
embryo sac
integument
megaspore
17Pollination
- the transfer of pollen from an anther to a
stigma, - does not imply fertilization,
- Vector,
- the means of transfer.
18Pollinationvectors
19Pollinationvectors
20Pollination / Speciation
- Differences in alpine skypilot populations are
due to differential selection by pollinators.
21Anthers / Dehiscence
Pollen Sacs
Dehiscence pollen sacs break, pollen is
released.
22Self-Fertilization
- acceptable in some species,
- prohibited in others,
- dioecious plants,
- moneocious plants with timing differences,
- structural (i.e pin and thrum),
- S alleles (genetic compatibility).
23Self Incompatibility
Box 40.2
- Alleles alternate versions of a gene,
- diploid organism have two copies of every gene
(one from mom, one from dad), - in a population, many alleles may be present.
- S genes self-compatibility genes,
- genes whose products block fertilization by
like individuals, - S-locus the genomic location of the S genes.
24Self Incompatibilitymodes
- Gametophytic (pollen)
- blocking process occurs within the pollen,
- i.e. incompatible (self) pollen allows the import
of RNA degrading enzymes,
- Sporophytic (stigma),
- carpel tissue blocks pollen function,
E (effector) protein blocks pollen function.
25Pollen Germination
- Metabolic rates are low in pollen grains,
- Germination,
- tube cell tip growth under proper stimuli,
- Tubes of cytoplasm form and lengthen allowing the
movement of sperm nuclei.
26Pollen Tube
http//www.bio.umass.edu/hepler/Images_movie_2.htm
Guided by stigmatic signals, not by environmental
cues.
27Pollen Tube Growth Double Fertilization
Fig 40.14
Generative cell divides ...to become two sperm
nuclei in the pollen tube,
Pollen germinates pollen tube begins to grow
down style,
28Lilium
29Embryo Sac Development( female gametophore)
embryo vasculature forms and primary meristems
are established.
daughter cells divide into a mass of cells
(proembryo), and a string of single cells
(suspensor),
Fig 40.15
30See Fig 40.16
Embryo Development storage
- Endosperm nuclei (3n) divide forming rich
nutritious material, - cytokinesis follows and partitions the nuclei
between membranes, - most dicots absorb the nutrient of the endosperm
into their cotyledons before germination,
- most monocots (and some dicots) use endosperm
after the seed germinates,
31Fruit maternal
32Today
- Spore formation,
- Gamete formation,
- Pollination,
- Fertilization,
- Germination.
33Dormant Seeds
- Dormancy slow metabolic rate and suspension of
growth and development, - seed coat dormancy (seed coat impermeable to O2
and H2O), - release by scarification (fire, abrasion,
digestive tracts, etc.), - internal dormancy (physiological),
- the most common internal dormancy is a
requirement for cold, - release by stratification (cold treatment).
Know these terms.
34Seed Germinationphase changes
- Dormant to metabolically active,
- etiolated growth (dark growth),
- respond to gravity,
- light,
- temperature,
- touch,
- De-etiolation (dark to light habit),
- vegetative growth program.
35Home Stretch
- Responses to internal and external signals are
studied (to a large extent) by studying the
genetics and physiology of...
Germination (phase change) Etiolated
Growth De-etiolation (phase change)
Signal Transduction Hormones Photomorphogenesis Gr
avitropism others...