Biology 200 - Chapter 20: Bryophytes

Comprehensive practice flashcards covering the characteristics, phyla, and reproduction of Bryophytes as detailed in the Chapter 20 lecture notes.

Which pigments do plants and green algae share as a key physiological feature?

Chlorophylls $a$ and $b$, and carotenoids

What is the shared food reserve found in both plants and green algae?

Starch

What structural material is found in the cell walls of both plants and green algae?

Cellulose

Which two structures are shared by plants and green algae during the process of cell division?

Phragmoplast and cell plate

According to fossil evidence, when did land plants first appear?

$400$ million years ago

What fatty substance developed on plant surfaces to prevent drying by retarding water loss?

Fatty cuticle

What are gametangia in land plants?

Multicellular gamete-producing structures surrounded by a jacket of sterile cells

What are sporangia in land plants?

Multicellular spore-producing structures surrounded by a jacket of sterile cells

Where do zygotes develop into multicellular embryos in land plants?

Within parental tissues that originally surrounded the egg

Name the three phyla identified as Bryophytes in the lecture introduction.

Phylum Hepaticophyla, Phylum Antherocerophyta, and Phylum Bryophyta

Approximately how many species of bryophytes are currently known?

About $23,000$ species

What is the maximum elevation mentioned where bryophytes can be found?

$5,500$ meters or more

Which fungi are often found associated with the rhizoids of bryophytes?

Mycorrhizal fungi

What is the ecological importance of peat mosses?

They are ecologically important in bogs

What specialized feature do luminous mosses use to concentrate light on chloroplasts?

Lenslike cells

Do bryophytes possess true xylem or phloem tissues?

No, none have true xylem or phloem

What specialized cells are used by many bryophytes for water conduction?

Hydroids

What specialized cells are found in a few bryophytes for food conduction?

Leptoids

What environmental factor is required for bryophytes to reproduce sexually?

External water

In the alternation of generations in mosses, what is the major part of the gametophyte generation?

The leafy plant

What does the sporophyte generation of a bryophyte produce?

Spores

How did the distinct lines of bryophyta likely arise relative to other plants?

They may have arisen independently from ancestral green algae

In Phylum Hepaticophyta, what percentage of liverwort species are categorized as thalloid?

About $20\%$

In Phylum Hepaticophyta, what percentage of liverwort species are leafy?

About $80\%$

What is a protonema in the context of liverwort development?

An immature gametophyte consisting of short filaments produced when spores germinate

What structure anchors thalloid liverworts on their lower surface?

One-celled rhizoids

Which genus is the best known among thalloid liverworts?

Marchantia

What characterizes the growth pattern of the Marchantia thallus?

It forks dichotomously as it grows

From which layer of the Marchantia thallus do rhizoids and scales arise?

The bottom layer (Epidermis)

What marks the limits of the air chambers on the upper surface of Marchantia?

Diamond-shaped segments

What is the function of the small bordered pores in Marchantia thalli?

They open into chambers containing erect rows of cells with chloroplasts

How does Marchantia perform asexual reproduction?

By means of gemmae

What are gemmae?

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

Where are gemmae produced on the Marchantia thallus?

In gemmae cups scattered over the upper surface

What is the term for the male gametophore in Marchantia?

Antheridiophore

What is the term for the female gametophore in Marchantia?

Archegoniophore

What is a distinctive feature of Marchantia sperm?

They have numerous flagella

How are archegonia arranged on the archegoniophore in Marchantia?

They sit in rows and hang down beneath the spokes

What is the function of the foot in a liverwort sporophyte?

It anchors the sporophyte to the archegoniophore

What is the seta in the Marchantia sporophyte?

A short stalk

What are elaters and what is their role in liverworts?

Cells with spiral thickenings in the capsule that twist and untwist rapidly to aid spore dispersal by breaking up the spore mass

What is the calyptra in bryophytes?

Caplike tissue that grows out from the gametophyte to protect the immature sporophyte

What is a distinguishing structural feature of leafy liverwort leaves compared to true mosses?

They have no midrib

What distinctive organelles are found within the cells of leafy liverworts?

Oil bodies

Describe the appearance of mature Phylum Anthocerophyta sporophytes.

They look like miniature greenish-blackish rods

What is unique about the chloroplasts in the cells of hornworts?

Each cell contains only one large chloroplast

Besides fragmentation, what other structure do some hornworts form for asexual reproduction?

Tiny tubers

Where is the meristem located in a hornwort sporophyte?

Above the foot

Into which three classes is Phylum Bryophyta divided?

Peat mosses, true mosses, and rock mosses

Describe the thickness of the leaf blade in most moss gametophytes.

Nearly always $\text{one-cell thick}$, except at the midrib

What two types of cells are found in peat moss leaves?

Large transparent water-absorptive cells and small green photosynthetic cells

What are paraphyses in moss anatomy?

Multicellular filaments scattered among the archegonia or antheridia

Describe the flagella of moss sperm cells.

Each sperm cell has a pair of flagella

What is the peristome in mosses?

One or two rows of teeth under the operculum that open or close in response to humidity for spore release

Identify three human or ecological uses for peat mosses.

Soil conditioner, fuel, and poultice material (due to antiseptic properties)