p.1
Classes and Subclasses of Bryophytes
What are the three classes of Bryophytes?
Hepaticopsida (liverworts), Anthocerotopsida (hornworts), and Musci (mosses).
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Life Cycle and Reproductive Structures
What is the dominant stage in the life cycle of Bryophytes?
The gametophyte stage, which is haploid.
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Reproductive Strategies in Marchantia
How do sperm reach the ovum in Bryophytes?
Sperm swim to the ovum by chemotaxis in a water film.
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Morphology of Gametophytes and Sporophytes
What is the structure of the diploid sporophyte in Bryophytes?
It consists of a basal foot, an elevating seta, and a terminal sporangium (capsule).
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General Characteristics of Bryophyta
What are Bryophytes?
Non-vascular plants that have no seeds, no roots, and no vascular tissue.
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General Characteristics of Bryophyta
What type of ancestors did Bryophytes evolve from?
Green algal ancestors, closely related to Charophytes.
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Morphology of Gametophytes and Sporophytes
What are the two forms of plant body in Bryophytes?
Thalloid attached by rhizoids or differentiated into stem-like and leaf-like structures.
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Reproductive Strategies in Marchantia
What is the function of archegonia in Bryophytes?
It is the female sex organ that produces a single egg.
p.3
Morphology of Gametophytes and Sporophytes
What are the two layers of the Marchantia thallus?
An upper photosynthetic region and a lower storage region.
p.3
Anatomy and Structure of Marchantia
What are the two types of rhizoids found in Marchantia?
Smooth walled and tuberculate.
p.6
Reproductive Strategies in Marchantia
How are antherozoids attracted to the archegonium?
They are attracted chemotactically towards the neck of the archegonium.
p.4
Anatomy and Structure of Marchantia
What are the two types of appendages in the described structure?
1) Appendigulate - with an apical subrotund appendage; 2) Ligulate - small, without appendage.
p.5
Morphology of Gametophytes and Sporophytes
What features can the margins of gemma cups have?
Hyaline, lobed, spiny, or entire.
p.2
Life Cycle and Reproductive Structures
What is a protonema?
A mass of green, branched, one-cell-thick filaments that grow into gametophytes.
p.6
Germination and Development of Bryophyte Spores
What happens to spores under favorable conditions?
They absorb moisture and increase in size.
p.3
Classification and Subclassification of Bryophytes
What class is Marchantia classified under?
Hepaticopsida or Marchantiopsida.
p.2
Morphology of Gametophytes and Sporophytes
How do hornwort sporophytes differ from those of mosses?
Hornwort sporophytes resemble grass blades and have a cuticle, while moss sporophytes are larger and more complex.
p.2
Morphology of Gametophytes and Sporophytes
How do the gametophytes of mosses and some liverworts differ from those of hornworts?
Mosses and some liverworts have more 'leafy' structures with stemlike features, while hornworts are flattened.
p.2
Classes and Subclasses of Bryophytes
What are the two orders within the Marchantiidae subclass?
Marchantiales and Sphaerocarpales.
p.4
Anatomy and Structure of Marchantia
What is the function of the appendages?
Protection of the growing point and retention of water by capillary action.
p.6
Life Cycle and Reproductive Structures
What leads to the scattering of spores in the air?
Jerky movement of elaters due to their hygroscopic nature.
p.2
Importance of Bryophytes in Ecosystems
What role do bryophytes play in rainfall interception?
They are effective rainfall interceptors, helping to prevent soil erosion.
p.4
Reproductive Strategies in Marchantia
How does vegetative reproduction occur?
Through progressive death and decay, with new cells formed by the apical cell.
p.6
Life Cycle and Reproductive Structures
What causes the valves of the sporophyte capsule to roll back?
Annular thickening in jacket cells.
p.6
Germination and Development of Bryophyte Spores
What structure do spores form after repeated divisions?
A 6-8 celled filamentous structure with a rhizoid at one end.
p.4
Reproductive Strategies in Marchantia
What are adventitious branches?
Branches that some species possess on the ventral surface, which can grow into new thalli when separated.
p.6
Anatomy and Structure of Marchantia
What is located at the tip of the neck in archegonia?
A rosette of 4 cover cells.
p.5
Reproductive Strategies in Marchantia
What arises from the floor of the gemma cup?
Many small, stalked, discoid, and biconvex gemmae.
p.5
Importance of Bryophytes in Ecosystems
What role do mucilage hairs play in gemmae?
They imbibe water and help in the dispersal of gemmae.
p.5
Morphology of Gametophytes and Sporophytes
What is the structure of an antheridiophore?
It has a 1-3 cm long stalk that bears an 8-lobed peltate disc.
p.2
Morphology of Gametophytes and Sporophytes
What type of sporophytes do liverworts have compared to other bryophytes?
Liverworts have the simplest sporophytes among bryophytes.
p.2
Life Cycle and Reproductive Structures
What happens to moss sporophytes as they prepare to release spores?
They turn tan or brownish red.
p.1
General Characteristics of Bryophyta
What is unique about Bryophyte sporophytes compared to other plants?
They have the smallest and simplest sporophytes of all modern plants.
p.6
Germination and Development of Bryophyte Spores
What does the apical cell of the filamentous structure give rise to?
It cuts off derivatives on lateral sides and finally gives rise to the gametophyte.
p.3
General Characteristics of Bryophyta
What type of plants are Marchantia?
Simple plants without roots or vascular systems.
p.6
Anatomy and Structure of Marchantia
What are the neck cells in the neck of archegonia?
6 vertical rows of cells that enclose 4-8 neck canal cells.
p.2
Morphology of Gametophytes and Sporophytes
What feature do the sporophytes of hornworts and mosses share with vascular plants?
They have epidermal stomata.
p.1
Life Cycle and Reproductive Structures
Why are Bryophyte sporophytes dependent on gametophytes?
They depend on gametophytes for sugars, amino acids, minerals, and water.
p.5
Reproductive Strategies in Marchantia
What structures do male and female thalli bear in Marchantia?
Male thallus bears antheridiophores and female thallus bears archegoniophores.
p.5
Reproductive Strategies in Marchantia
What does the venter of an archegonium contain?
A large egg cell and a relatively small venter canal cell.
p.3
Anatomy and Structure of Marchantia
What color are the scales on the ventral surface of Marchantia?
Violet, due to anthocyanin pigments.
p.2
General Characteristics of Bryophyta
Why are bryophytes limited to moist habitats and small size?
Due to the absence of vascular tissue.
p.5
Germination and Development of Bryophyte Spores
What happens to gemmae when they come in contact with the ground?
They start germinating immediately.
p.2
Classes and Subclasses of Bryophytes
What are the two subclasses of the class Hepaticopsida or Marchantiopsida?
Marchantiidae and Jungermanniidae.
p.4
Anatomy and Structure of Marchantia
Describe the structure of air pores.
Barrel-shaped with 4-8 superimposed tiers of cells; each tier consists of a ring of 4-5 cells.
p.4
Reproductive Strategies in Marchantia
What is the role of gemmae in reproduction?
Gemmae are involved in asexual reproduction, allowing for the formation of new plants.
p.5
Reproductive Strategies in Marchantia
What are gemma cups?
Cupules present on the dorsal surface along the midrib region.
p.6
Reproductive Strategies in Marchantia
What occurs after antherozoids enter the archegonium?
Only one antherozoid fuses with the egg, leading to the formation of a zygote.
p.2
Morphology of Gametophytes and Sporophytes
What are rhizoids?
Tubular cells or filaments of cells that anchor bryophytes.
p.5
Reproductive Strategies in Marchantia
What is the function of the ostiole in antheridia?
It is a pore through which water enters the antheridial chamber.
p.4
Anatomy and Structure of Marchantia
What characterizes the storage region in the structure?
A compact zone of several layers of polygonal parenchymatous cells, devoid of chloroplasts and intercellular spaces.
p.3
Morphology of Gametophytes and Sporophytes
What is the structure of the dorsal surface of Marchantia?
It has a shallow groove with a distinct midrib, polygonal areas, air pores, and gemma cups.
p.6
Reproductive Strategies in Marchantia
What happens to the venter canal and neck canal cells during fertilization?
They degenerate to form a mucilaginous substance that imbibes water.
p.5
Anatomy and Structure of Marchantia
What types of cells does a gemma contain?
Chloroplast-containing cells and rhizoidal cells.
p.2
Importance of Bryophytes in Ecosystems
What is the significance of bryophytes in ecosystems?
They prevent soil erosion, provide food for animals, and contribute to nutrient cycles.
p.5
Morphology of Gametophytes and Sporophytes
What is the structure of an archegonium?
A stalked flask-shaped structure with a basal swollen venter and an elongated neck.
p.4
Anatomy and Structure of Marchantia
How do the cells in the lowermost tier of air pores appear?
They project inward, giving the pore a star-shaped appearance.
p.6
Reproductive Strategies in Marchantia
Why is water essential in the fertilization process?
It facilitates the movement of antherozoids to the archegonium.
p.5
Morphology of Gametophytes and Sporophytes
What is the structure of a gemma?
Constricted in the middle with two notches possessing a row of apical cells.
p.5
Reproductive Strategies in Marchantia
What happens during the dehiscence of an antheridium?
Water causes some cells to disintegrate, rupturing the antheridium and releasing antherozoids.
p.4
Anatomy and Structure of Marchantia
What is the photosynthetic region's location and structure?
Lies below the upper epidermis, consisting of large air chambers separated by single-layered partition walls.
p.3
Habitats and Ecological Roles of Bryophytes
What is the growth habitat of Marchantia polymorpha?
Cool, moist, and shady places.
p.6
Life Cycle and Reproductive Structures
How does the sporophyte capsule dehisce?
The single-layered capsule wall splits into longitudinal valves extending from apex to middle.
p.5
Reproductive Strategies in Marchantia
What type of plant is Marchantia?
A heterothallic or dioecious plant.
p.5
Morphology of Gametophytes and Sporophytes
What is the structure of an archegoniophore?
It has a slightly longer stalk and a terminal disc that is 8-lobed.
p.2
Life Cycle and Reproductive Structures
What structures do protonema produce when resources are available?
Meristems that generate gamete-producing structures called gametophores.
p.2
Importance of Bryophytes in Ecosystems
What commercial use does peat moss (Sphagnum) have?
It is used as fuel, soil conditioner, and by florists.
