Bryophytes

What are the three phylums in Bryophytes?

Phylum Hepaophyta (Liverworts)

Phylum Anthocerophyta (hornworts)

Phylum Bryophya (mosses)

Are bryophytes considered vasular or nonvascular plants?

Non-vascular plants

What are the six characteristics that byrophytes and vascular plants share that differ from charophytes (green algae)?

1. presence of male and female gametangia, antheridia and archegonia

2. retention of both the zygote and the developing multicellular embyo or young sporophyte within the archegonium or female gametophyte

3. presence of a multicellular diploid sporophtye, which results in an increased number of meiosis and an amplification of the number of spores that can be produced by each fertilization event.

4. multicellular sporangia consisting of a sterlie jacket layer and internal spore-producing (sporogenous) tissue.

5) meiospores w/ walls containg sporpollenin, which resists decay and drying

6) tissues produced by an apical meristem.

What type of life cycle do borophyte have?

Alternating heteromorphic gametophytic and sporophytic generation.

Gametophyte is larger and free living. Sporophyte is smaller and permanently attached to and nutrionally dependent on parentlal gametophyte. (This is opposite of vascular plants)

True or False

DNA sequence data from present-day plants suggests that earliest plants diverged from charophytes were similar to present-day bryophyte.

True

Molecular data support that liverworts, hornworts or bryophytes are sister to all remaining land plants?

liverworts, hepatophyta

What bryophytes have thalloid? What is it?

a) namely the hornworts and certain liverworts

b) dorsiventrally flattened; dorsal side as pores and ventral side has rhizoids and scales.

Marchantia represents which phyla in Bryophytes?

Phylum Heptophyta: Thallose liverworts

The gametophytes in Marchantia (thalloid liverwort) are unisexual or bisexual? Name the parts.

Unisexual.

Antheridia are borne on disk-headed gametophores caleld antheridiophores

archegonia are borne on umbrella-headed gametophores called archegoniaphores.

What are the elongate cells called in a mature sporangium of a Marchantia (thalloid liverwort)? What does it do?

Elaters.

Helps disperse spores due to changes in humidity.

What does the sporophyte generation consist of in Marchantia (thalloid liverwort)

Foot, short Seta and a capsule.

Fragmentation is the principle means of asexual reproduction, but another mechanism is is the production of GEMMAE. Where is it produced? How is it dispersed?

Produced in gemma cups located on the dorsal surface of the gametophyte

dispersed by splashes of rain.

Life Cycle of Marchantia

Young sporophyte (2N) contained inside of the archegonia undergoes meiosis creating spores (N) inside the Mature sporophyte (2n). Spores will give rise to either male or female gametophytes.

Fertilization occurs when the rain falls and transfers motile sperm onto the female archegonial head which swims down the venter and fertilizes the egg forming the zygote which grows into the young sporophyte which will eventually rupture the enlarge calyptra. The sporophyte is permanently attached to the gametophyte by the foot.

Asexual reproduction takes place in the Gemma cup of the gametophyte.

Where is the archegonia located on the archegonial head on the Merchantia?

Underneath the archegonial head.

Where is the antheridia located on the antheridial head of Merchantia?

On the top of the antheridial head

In Merchantia, what are the parts of the mature sporophyte starting at the foot of the gametophyte down?

Foot, Seta, the sporangium (2N) with spores (n) inside

How can one distinguish a liverwort leaf from a moss leaf?

moss leaves are equal in size and spirally arranged around the stem. Liverworst have 2 rots of equal-sized leaves and a 3rd row of smaller leaves along the lower surface of the gametophyte.

Gametophytes of Phyla Anthocerophyta; hornworts are superficially similar to what?

Thallose liverworts, phyla hepatophyta.

The cells of a Anthocerophyta contain a large central chlorophase with what structure?

Pyrenoids

Anthrocerophyta have extensive internal cavities inhabited by what bacteria that helps fix nitrogen?

cyanobacteria

What is a unique aspect of anthocerophyta that has to do with their meristem between the foot and the sporangium?

It is actively dividing, so that the sporophyte continues to elongate for a prolonged period of time.

What links mosses and liverhorns to evolutionarily to vascular plants?

stomata.

What class within Phylum Bryophyta are the "true mosses"?

Bryidae

The branching filaments of Phyla Bryophyta consists of how many rows?

single row of cells

In Phylum Bryophyta, leafy gametophyte will develop from what structure?

bud-like structure on the Protonema

Are the rhizoids of Phylum Bryophyta multicellular or unicellular?

Multicellular

How many cells thick is the leaf of phylum Bryophyta

One cell thick except at the midrib

What is a hadrom and hadroid? Where is it found and in which phylum?

Hadrom is a water conducting tissue and Hadroid is the water conducting cells found in the stems of gametophyte and sporophytes of Phylum Bryophytes.

what do hadroids resemble? What do hadroid lack?

trachery elements of vascular plants b/c they both lack a living protoplast at maturity.

Lack specialized, lignin-containing wall thickenings.

What is leptom and leptoids? Where is it found and in what phyla?

Leptom is the food-conducting tissue and leptoids are the cells. It surrounds the strands of hydroids in the stem of gametophytes and sporophytes in phyla Bryophyta

What type of asexual reproduction does phylum bryophyta undergo?

Fragmentation and sometimes produce Gemmae

How can one tell the difference from a hydroid and leptoid?

Hydroid is in the center and is much larger than the leptoid cells.

What are capsules in Phyla Bryophyta?

The sporangia

Does phyla Bryophyta have stomata?

Yes, are present on epidermis of moss and some are bordered by a single, doughnut shaped guard cell.

In Phyla Bryophyta, what stage of it's life does it have chloroplasts and when does it lose it?

Young and maturing sporophytes contain chloroplasts to carry out photosynthesis but as it matures it will lose its ability to photosynthesize and go from green to yellow, orange than brown.

What is the calpytra derived from? In the Bryophyta when the capsule elongates, what happens to the calpytra?

The female archegonia. It will be lifted upward with the capsule.

What is the peristome in phyla bryophyta?

when the operculum burst off the capsule revealing a ring of teeth that curl up when moist and uncurl when dry which release spores.

Within bryophytes, which phyla have stomata?

Anthocerophyta and Bryophyta

Within the bryophytes, which phyl have elaters?

Hepatophyta and anthocerophyta

Within bryophytes, which phylas have cond. tissue?

Bryophyta

In bryophytes, which phyla have protonema?

Hepatophyta rarely

anthocerophyta no

bryophyta yes.

thallus

The body of a plant-like organism that is not divided into leaves, roots, or stems.

Liverworts characteristics

No conducting tissue, but in some a strange type of conducting cell

- Separate evolutionary line from other plants

-Most do not have a cuticle. No stomata -- pores instead

-May be thalloid or leafy

Leafy liverworts: Frullania characteristics

-Small, one cell-thick leaves in gametophyte

-Distinctive scale (leaf) arrangement: (Fig. 16-16, page 378)

-Two rows of equal sized scales and a third row of smaller scales on the lower side; often lobed

-No midrib or veins

thalloid liverworts: Marchantia characteristics

Thallus structure (Fig. 16-4, page 369), some with protonemata --

dichotomous branching

• Thalloid gametophytes -- undifferentiated plant body, lack leaves and

stems, attached with rhizoids

• Sporophyte -- foot, seta (stalk), capsule (sporangium), hygroscopic elaters. Non-photosynthetic.

-Elaters - hygroscopic cells that undergo a shape change in response to moisture/drying and help disperse spores

sexual reproduction for thalloid liverwort

Antheridiophores and archegoniophores (Fig. 16-11, page 374)

-Splash cup - sperm dispersal by rain/water drops

asexual reproduction for thalloid liverwort

o Fragmentation

o Gemmae -- multicellular structures that resist desiccation and

can produce new gametophytes. Gemma cups. (Fig. 16-13, page 375)

-

Bryophyta classes

Sphagnidae, Andreaeidae, Bryidae