ESF Diversity of plants lab practical 2

bryidae life cycle

*has meiospores, sperm has two flagella

2 strongest synapomorphies for lycopsid clade

*stalked kidney bean shaped sporangia* clearly united to one another and fossil kin by this character, allows for phylogenetic resolution in lycopsid lineages

vascular plants characters

- conspicuous and long lived plant body - sporophyte - vasc system of x and p - presence of multicellular archegonia

selaginella life cycle; how is it different?

- very differential embryo; shoot and root apical meristem multicellular * endosporic *gametophyte tissue food for developing embryo, like seed plants*

sporophyte of selaginellaceae

-conspicuous megasporophylls > strobili > megasporangia > megaspores (large, few, yellow) micro for male (red, many small spores)

economic importance of lycopodium

-homeopathic remedies for memory, ear aches, sore throats, digestive disorders, ut problems, blood vessles, bones, joints liver and heart. -pyrotechnics/photography -floral industry -lubricant

lycopodiophyta characters and classes

-homosporous and heterosporous -microphylls -motile sperm -low growing, herbaceous, usually understory/epiphytic plants -common in wet tropics, also canopy dwellers lycopodium, selaginella and isoetes

Family selaginaellaceae

-only has a single genus, 750 sp growing in tropics -all sp are HETEROSPOROUS either develop into microgametophyte or megagametophyte

leptosporangiate (define, which pteridophytes)

-sporangium arises from a *single initial cell* and whose wall is composed of a single layer of cells, capable of spore discharge -stalked sporangium w/ annulus -active spore dispersal -circinate venation POLYOPSIDA & SALVINALES

eusporangiate (define, which pteridophytes)

-sporangium that comes from *several initial cells*, forms a wall of more than one cell layer thick -passive spore discharge -no circinate venation -no stalk PSILOTOPSIDA, MARATTIOPSIDA, EQUISETOPSIDA

microphylls

1 strand of vascular tissue

Marchantia gametophyte cross section

1- parenchyma cells 2-rhizoids (1 cell layer) 3- pores 4-chloroplasts 5(not there but under 3)- epidermis

polypodiopsida habitats and how many

12,000 sp, 320 genera, 35 families diverse in tropics, many in temperate forests, arid habitats. many diversified after conifer and angiosperm radiations.

3 classes of bryophytes

:bryidae, sphagnidae, andreae

ground cedar

L. tristachyum

multicellular sex organs of marchantia

PRODUCED ON SEPARATE 'MALE' AND 'FEMALE' PLANTS antheridia - antheridial disks evelated on antheridiophore a few mm above thallus. In presence of water, produce many motile sperms surrounded by sterile protective cells and are embedded in the upper surface of the antheridial disk. Antheridia rupture and reach archegonium through water. archegonia - archegonial disk on archegoniophore pendant at maturity

2 species of selaginella have also been collected from onondaga county. Seligenella apoda is usually found in wet places whereas S. rupestris is from relatively dry areas. What morphological criteria can you use to differentiate these 2 sp?

S. rupestris - dense, fluffier looking, likely retains more h2o when wet like a sponge S. apoda - smaller, daintier, doesn't need to hold water constantly.

homosporous

all spores produced are same bisexual gametophytes self fertilization potential monoicous

primary function of root system by ancient lycopods

anchoring

isoetes is nearest living relative to

ancient tree lycophytes of the carboniferous (lepidodendrales), sharing the feature of secondary xylem, vasc cambium secondary xylem may have evolved multiple times through convergent evolution

when did arborescent 40 m tall lycophytes dominate and why did they go extinct

carboniferous; coexisted with small herbaceous lycophytes. became extinct at beginning of permian when the climate cooled

describe at least one technique used by paleobotanists to study fossil plants and the kind of info that can be obtained from it

cellulose acetate peel replicas of etched surfaces embedded in sheets of cellulose acetate; replicas so detailed that the microstructures of plants can be easily studied under a light microscope.

protostele and three types

central core of vascular tissue, cylindrical strand of xylem, surrounded by a region of phloem. might have been an endodermis that regulated the flow of water into and out of the vascular system haplostele, actinostele, plectostele

Lycopodiaceae

club mosses -small, simple, microphyllous (only 1 vasc strand, no leaf gap) leaves irregularly or spirally arranged in vertical rows -sporangia borne in sporophylls, axils of fertile leaves -sporophylls commonly reduced and grouped in terminal cones strobili

mnium capsule longitudinal section; where is the columella and what does it contain?

columella long central column of sterile cells

habitat of lepidodendron?

dense stands in wet areas of prehistoric coal swamps

most significant factor for vp evolution

development of vasc system for effective translocation of waters, minerals and sugars to all parts of plant body

heterosporous

different spores m and f spore give rise to m and f gametes unisexual less chance for selfing dioicous

major difference in n/2n generations between mosses and 'higher' plants

dominant sporophyte, gametophyte dependent or free living

lycophytes and pteridophytes arrived

during the late devonian to the mid-silurian ~ 375-290 mya

exospory vs endospory

exospory: gametophyte develops outside of spore wall endospory: gametophyte develops begin developing within spore wall

label parts of polytrichum

foot - attaches sporophyte to the gametophyte plants seta - stalk capsule - spore producing strucutre calyptra - (covering for the head) is gametophytic tissue derived from the wall of the archegonium in which the sporophyte developed operculum - small lid covering very end of capsule peristome - teeth holding sentral disk (annulus) in place

sporophyte of marchantia (describe formation)

formed after sperm cells swim to the neck of archegonium and up to egg cell, leading to fertilization and then formation of a zygote. the zygote divides repeadetly within archegonium to form a multicellular sporophyte, the 2n generation, which remains attached to and is nutritonally dependent on the gametophyte

Asexual reproduction in Marchantia can result from

fragmentation of its body OR by dispersal of specialized structures called gemmae found in cups. (two arrows = growing points)

What large alga showed similar dichotomous branching to Marchantia polymorpha

fucus

granite moss: tetraphis pellucida what feature does this have in common with liverworts?

gemmae cup

class andreaeiade

granite mosses alpine or subalpine habitats grow on granite rocks common in high peaks of adirondaks * gametophyte like a moss * capsule more similar to a liverwort

similarity between bryophyte, lycophyte and pteridophyte sperm are reliant on

h2o for successful fertilization

female moss plant

have terminal leaves bent inward to form a slender tip

function of elaters in marchantia sporophyte?

help shoot spores further

lycopodiaceae members all homosporous or heterosporous?

homosporous

phylum anthocerophyta

hornworts **have a reduced protonema -primarily tropical-sub tropical areas -biflagellate sperm, rely on aquatic env -ecological pioneers, grow in areas with little to no competition

which species on display does not have sporangia borne in cones?

huperzia lucidula

conducting cells inside of mosses

hydroids and leptoids

sporophyll

leaf containing gametes

phylls

leaves

moss sporophyte formation describe

like liverworts, fertilization takes place in water. The zygote, the first cell of the sporophyte generation, develops in archegonium and through successive mitotic divisions, leads to the multicellular sporophyte which remains anchored to the archegonial gametophore during its short life

phylum marchantiophyta (characters and common name)

liverworts; has a plant body that is dorsoventrally orientational, thallus like or leafy and usually prostrate

lycopodium clavatum

locate: root, underground stem, upright stem, microphylls and strobilus

Asteroxylon - extinct group of herbacous lycopods, what extant lycophyte was it compared to and what features were used in comparison

lycopodium - xylem (actinostele) star shaped

cross section of selaginella under microscope. find xylem and phloem how different is the anatomy of this plant from lycopodium?

lycopodium stele is a plectostele selaginella stele is a polystele/distellic (each stele is a protostele with xylem core surrounded by phloem with pericycle and epidermis)

Bryophytes (phyla and characters)

marchantiophyta, bryophyta, anthoceraphyta. -presence of motile sperms and dependence on h2o for successful fertilization -heteromorphic alternation of generation between conspiciuous nutritionally independent gametophyte (n) and small dependent sporophyte (2n) -lack vascular tissues -multicellular sex organs and multicellular embryos

moss costa

midrib of specialized cells that runs lengthwise of the "leaf"

specimen cross sections of ventral antheridia and archegonium we observed on slides

mnium

compare stem and leaf of lycopodium with stem-like and leaf like structures of moss mnium. how are they different?

mnium - no lignin, has hydroids and leptoid cells to conduct h2o lycopodium - has vascular tissue and therefore lignin

compare moss and lycopodium life cycles (ploidy levels, sporophyte gametophyte phases)

moss: dominant haploid gametophyte lycopodium: dominant diploid sporophyte, homosporous

Phylum bryophyta characters

mosses -erect stem-like structure bearing thin expanded sheets of cells that function like leaves. -rhizoids = anchorage -gametes protected until maturity by steril jacket cells (same as marchantia) -sporophyte produces sporangium in which numerous spore mother cells undergo meiosis to produce haploid spores

in what ways does moss photosynthesizing organs differ from a true leaf

no possession of lignin = no vascular tissue (true leaves have lignin therefore vt)

lepidodendron typical leaf scars

note features

hornwort life cycle

note protonema

herbarium mounts of lycopodium

note tiny oil rich spores are borne in spore cases or sporangia which are usually clustered into cones or strobili

why does hornwort sporophyte stay attached to parent?

nutritionally dependent on gametophyte

function of peristome

permit spore dispersal only in dry weather

explain what spines on sawdonia are and their possible evolutinary significance

photosynthesis, early leaves?

mature marchantia sporophyte diagram

placenta- ontop of foot foot- anchors structure in gametophyte tissues seta- short stalk capsule- terminal oval spores- red/green dots elaters- green and long

Pteridophyta

polyopsida, marattiopsida, psilotopsida, equisetopsida

which pteridophytes are homosporic?

polyopsida, marattiopsida, psilotopsida, equisetopsida

which pteridophytes are exosporic?

polyopsida, salvinales, marattiopsida, psilotopsida, equisetopsida

hair-cap moss examined in lab

polytrichum

comparing cooksonia and sawdonia to modern plants, what was the major indicator of the earlier plants' simplicity?

primitive vasc tissue

which part of marchantia life cycle is most vulnerable to environmental stress

protonema - looks like algae, acts like it no cuticle, wouln't last long w/o moisture

cross section of lycopodium stem; can you find any vascular tissue in the cortex of the stem? what does the presence of this structure indicate?

protostele plectostele -- vt = potential areas where microphylls would be connected to stem

Isoetaceae

quillworts, one genus 150 sp all HETEROSPOROUS -plant body relatively small with a greatly shortened axis and has tufts of leaves and roots -secondary xylem -grass-like -found in lakes, ponds, swampy areas and ephemeral pools

microsporophyll color

red

stigmaria

root of ancient lycopod trees composed of sandstone preserved due to sand and mud getting into caveties of trunk following death

which pteridophytes are heterosporic?

salvinales (shares this with isoetes and selaginella likely by convergent evolution)

early vps (name them) characterized by

small stature simple & primitive morphology rhyniophyta, zosterophyllophyta and trimerophyta dominant from mid silurian to mid devonian ~410-370 mya

spores of lycopodium give rise to

small subterranean gametophytes bearing both archegonia and antheridia

what does protonema closely resemble and how can you distinguish it?

soil inhabiting algae -- protonema has buds, disk like chloroplasts and has slanted cross walls while algae have perpendicular cross walls

note differences in foliar morphology based on a few reps

some are more smooth looking (like a single stem) others are leafy all over. some just leafy on tips

what part of the cycle indicates aquatic ancestry and explain

sperm - needs h20 to move and swim to egg to effectively fertilize protonema - needs h20

pteridophyte sperm?

still need water for movement, now have multiflagellate sperm so that plant may survive further from water.

lepidostrobus: what is it and when would it reproduce?

strobilus of lepidodendron individuals would reproduce once at end of its lifetime by way of encapsulated spores

male moss plant

terminal rosette of leaves in which the long, slender, stalked antheridia are embedded

why are hornworts less successful in moderate to dry environments?

the archegonium and antheridium are not close to eachother in 'pores' of the thallus so water allows them to open and sperm can move to archegonia

what could be a reason for a horn shaped sporophyte?

to get higher up so spores will be dispersed further and more effectively

class bryidae - what are the two distinct phases of the gametophyte?

true moses 1. protonema - when a spore germinates cell divides repeatedly to form an extensive branched filamentous body which gives rise to the... 2. gametophore which will develop into an upright moss plant

antheridial disk cross section: where are antheridia located on disk (upper/lower surface) and what is the significance of such a location?

upper surface for splash transport of sperm to archegonium

archegonial disk cross section: what is the swollen basal portion where archegonium are located called?

venter

where on the underside of Marchantia thallus are the rhizoids attached

ventral side of thallus, not present on central line of ventral side

class sphagnidae economic importance and why

water retaining capacity - large dead cells with secondary thickening absorb and hold large quantities of water used to lighten heavy soils and improve water holding capacity of light sandy soils.

megaphylls

webbed vascular strands

what does presence of root system in ancient lycopods indicate about the nature of substrate during devonian period?

wet/ floating forests

what is sphagnum water holding capacity (ratio) and how

wet:dry weight 1:10 due to LARGE EMPTY CELLS in addition TO SMALLER PHOTOSYNTHESIZING CELLS in mature leaf-like structures green cells = living large clear cells = dead

psilotopsida

whisk ferns order psilotales psilotum (L) and tmesipteris (r) -lack true roots and true leaves. -upward growing stems green and psynthetic. -rhizomes or lateral stems -ephiphytic * because they lack leaves they were og though to have been modern descendents of early vps like rhinyophytes, molec evidence proves they are more closely related to ferns *ophioglossales (grape ferns, once under polypodiopsida) being considered for psilotopsida

megasporophyll color

yellow