Chapter 20: Bryophytes

Which type of chlorophylls are shared between plants and green algae?

Chlorophylls a and b, carotenoids

What acts as food reserve in both plants and green algae?

Starch

What do both plants and green algae contain in cell walls?

Cellulose

What is involved in cell division of both plant and algae?

Phragmoplast and cell plate

What do the shared features in plants and green algae suggest?

A common ancestor

How long ago did land plants and green algae first appear?

Around 400 million years ago

What do shared ancestors between plants and green algae progress from and to (even earlier)?

From aquatic to land habitat

Which feature do plant surfaces develop to retard water loss?

Fatty cuticles

Which two structured features in plants become multicellular and surrounded by jacket of sterile cells?

Gametangia (gamete-producing structures), sporangia (spore-producing structures)

What is a plant feature that involves zygotes?

Zygotes developed into multicellular embryos within parental tissues, originally surrounding egg

Phylum Hepaticophyla

The liverworts

Phylum Antherocerophyta

Hornworts

Phylum Bryophyta

Mosses

How many species of bryophytes have been established?

About 23,000 species

Which mosses are included in Bryophyte species?

Mosses, liverworts, and hornworts

What type of habitats do Byrophyte species occupy?

Damp banks, trees, logs, frozen alpine slopes, bare rocks in scorching sun

What length of elevations do Bryophyte species also occupy?

From sea level up to 5,500 meters or more

What do Bryophytes often have associated with their rhizoids?

Mycorrhizal fungi

Which type of mosses are ecologically important in bogs?

Peat mosses

Where are luminous mosses typically found in?

Caves, other dark, damp places

What kind of “like cells” do luminous mosses have that concentrate light on chloroplasts?

Lenslike cells

What do many Bryophyte species have for water conduction?

Hydroids

How is most water absorbed by Bryophyte species?

Directly through surface

What do a few Bryophyte species have for food-conductions?L

Leptoids

What must Bryophyte species have to sexually reproduce?

External water

What do Byrophytes exhibit alternation in?

Generations

In mosses, what is leafy plant a major part of?

Gametophyte generation

What does sporophyte generation grow from?

Gametophyte

What does sporophyte produce?

Spores

What is the number of distinct bryophyte phyla?

Three distinct bryophyte phyla

Bryophyte lines may have arisen independently from:

Ancestral green algae

What is the structural formation of most common and widespread Phylum Hepaticophyta? (Liverworts)

Flattened, lobed thalli

What percent of species do thalloid liverworts constitute?

About 20% of species

What precent of the Phlyum Hepaticophyta (Liverworts) species is leafy?

80%

What do thalli or leafy gametophytes develop from?

Spores

What may spores in Phylum Hepaticophyta (liverworts) produce when they germinate?

Protonema

In thalloid liverworts growth is:

Prostrate

Which root-like structure anchors the plant in thalloid liverworts?

One-celled rhizoids on the lower surface

Which species is considered “best known” in genus Marchantia?

Thalloid Liverworts

What occurs in Thallus during the growth of a Thalloid liverwort?

Thallus forks dichotomously

What does each branch in the Thallus consist of?

A notch at apex and a central groove

Which cells continue to divide in a notch of a Thallus branch?

Meristematic cells

Where is the epidermis located in the Thallus?

Bottom layer, which rhizoids and scales arise from

What is the upper surface of Marchantia divided into that mark the limits of the chambers below?

Diamond-shaped segments

What does each segment of the Marchantia consist of?

A bordered pore opening into chamber

What type of cells sit on the floor of each Marchantia segment chamber?

Short, erect rows of cells with choroplasts

What does Marchantia produce asexually by means of?

Gemmae (gemma)

Gemmae

Tiny, lens-shaped pieces of tissue that become detached from thallus

Where is Gemmae in Marchantia produced during asexual reproduction?

In gamma cups scattered over upper surface of thallus

What is formed on gametophores in Marchantia during sexual reproduction?

Gametangia

What is a male gematophore in Marchantia known as?

Antheridiophore

Anteridiophore

Antheridia containing sperm found on upper surface

What do the sperm of male gametophore in Marchantia consist of?

Numerous flagella

What is formed on gametophores?

Gametangia

What is a female gametophore known as in Gametophores?

Archegoniophore

Archeniophore

Archegonia with eggs in rows, hanging down beneath spokes of archegoniophore

What is embryo dependent on for sustenance?

Gametophyte

What does the foot of sporophyte anchor to?

Archegoniophore

Seta

Short stalk

What does Meiosis produce inside of capsules?

Haploid spores

What do other non-meiosis cells inside of capsule develop into?

Elaters with spiral thickenings

How do Elaters react to humidity as a result of their sensitivity?

Twist and untwist rapidly to aid spore dispersal by breaking up spore mass

What is immature sporophyte protected by?

Calyptra

Calyptra

Catlike tissue that grows out from gametophyte

What does a capsule split at maturity to release?

Spores

What is the structure of “Leafy” Liverworts?

Two rows of partially overlapping leaves, no midrib, folds or lobs

What do the cells of “Leafy” Liverworts contain?

Oil bodies

What is the structural form of mature Phylum Anthocerophyta (Hornworts)?

Miniature greenish-blackish rods

What type of cells do gametophytes thalloid in Phylum Anthocerophyta contain?

Cells with only one large chloroplast

How does asexual reproduction primarily occur in Phylum Anthocerophyta?

Fragmentation

What may asexual reproduction appear as in Phylum Anthocerophyta?

As lobes that separate from the main part of the thallus

What so (some) Phylum Anthocerophyta form during asexual Reproduction?

Tiny tubers that can become new gametophytes

What is produced underneath the upper surfaces of gametophytes in Phylum Anthocerophyta during sexual reproduction?

Archegonia and antheridia (in rows)

What does the Meristem above foot continually increase length of during sexual reproduction of Phylum Anthocerophyta?

Sporophyte from base

What occurs in sporophyte to produce spores in Phylum Anthocerophyta during sexual reproduction?

Meiosis

Which similar function to liverworts intermingle with spores in Phylum Anthocerophyta during sexual reproduction?

Diploid elaters

How many species of mosses are currently known?

10,000

What do the three divided classes of mosses consist of?

Peat, true, and rock mosses

What type of blades do leaves of moss gametophytes nearly always have?

One-cell thick, except at midrib, and never loved or divided

What do the cells in leaves of moss gametophytes usually contain?

Numerous chloroplasts

What type of cells do Peat moss leaves have?

Large transparent cells without chloroplasts that absorb water and small, green, photosynthetic cells in between

The axis of a Peat moos leave does not contain:

Xylem or phloem

What do the stemlike axis in Peat moss often contain?

Central stand of hydroids

Where is the gametangia located in Phylum Bryophyta during sexual reproduction?

At apices of leafy shoots

What do the leafy shoots in Phylum Bryophyta contain during sexual reproduction?

Archegonium cylindrical with egg in swollen base, neck above containing narrow canal

Multicellular filaments (Phylum Bryophyta)

Paraohyses scattered among archegonia

Where is Antheridia found in Phylum Bryophyta?

On short stalks, surrounded by walls one cell thick

What type of cells are formed inside of cell walls of Phylum Bryophyta (Antheridia)?

Sperm cells, each with pair of flagella

Where is sperm forced out from in Phylum Bryophyta (Antheridia)?

On top of antheridium

What is scattered among the antheridia in Phylum Bryophyta (Antheridia)?

Paraphyses

Which type of structure releases substances that attract sperm?

Archegonia

What does the zygote grow into?

Spindle-shaped embryo

What does top of archegonium form after splitting off?

Cap on top of sporophyte (Calyptra)

What do mature sporophytes consist of?

Capsule, seta and foot

What process produces spores inside capsule?

Meiosis

Where is the peristome, composed of one or two rows of teeth, located in the capsule?

Under operculum at tip of capsule

What does peristome open and close in response to?

Humidity

What do spores develop into that produces bud-developing leafy gametophytes?

Filamentous protonema

How does asexual production of Mosses primarily occur?

Through fragmentation

What is a possible routine mode of moss dispersal in arctic regions?

Wind dispersal of fragments