bryophytes

Question 1

Land plants differ from Charophyceae by

Answer 1

• Male and female gametangia called antheridia and archegonia that have a protective layer (sterile jacket layer)
• Zygote and developing embryo are retained within the archegonium on the female gametophyte
• Sporophyte is multicellular=>increases the number of meiosis and the number of spores produced per single fertilization event
• Spores with walls containing sporopolleninresist decay and drying
• Tissues produced by apical meristem
  o Meristem = region of embryonic cells that makes new cells; like stem cells

Question 2

features

Answer 2

• No vascular plants
  o Lack water (xylem) and food tissues (phloem)
  o So they’re flat to compensate for this
• Lack true leaves, stems, and roots
• Have superficial cuticle and pores—liverworts

Question 3

structure

Answer 3

• Thallose
• Flat and thin gametophyte—undifferentiated
  o Helps with uptake water and CO2
  o Leaves small w/o veins
  o Stems w/ conducting cells
  o Rhizoids for fixation

Question 4

asexual reproduction

Answer 4

• Fragmentation or producing gemmae
  o Small pieces of gametophytes are detached and then regenerate an entire gametophyte (identical)
   Liverworts gametophyte produces gemmae in cups and rain helps with dispersal

Question 5

sexual reproduction

Answer 5

• Gametophytes can be dioecious (male/female) or monoecious (both sex present but separate)
  o Flagellated sperms (n) produced in antheridia
  o Eggs (n) produced in archegonia
   Venter and neck
• After fertilization the zygote (2n) attached to female develops sporophyte (2n)
  o Female gametophyte (n) provides sugars AA’s = matrotrophy
  o Placenta is transfer of cells with highly branched cell wall ingrowth. Incr. SA
• Mature sporophyte, meiosis produces spores (n)
  o Spores released from sporangia and dispersed by winds
  o Spores germinate into gametophyte
  o Directly or through protonema in all mosses and some liverworts

Question 6

Marchantiophyta (Liverworts)

Answer 6

• Leafy and thallose species
• Gametophyte grows directly from the spore
• Thin thallus with single celled rhizoids and scales for fixation to rocks and moist soils
• Gametangia born on gametophores
• Sporophyte dominant in alga
• Spore dispersion
  o Released form sporangia and dispersed by wind
  o Elaters are elongated cells that help with dispersion
   Sensitive to humidity
   Twist

Question 7

Sphagnum Moss

Answer 7

• Abundant
• Peat is accumulation and compression of sphagnum moss in cold wet places
• Sphagnum differs from other bryophytes
  o Protonema one layer thick
  o Leaves made of dead cells surrounded by small living cells
  o Absorbs water
  o Explosive operculum
   Burst and spores released

Question 8

Bryophyta (mosses)

Answer 8

• Leafy gametophytes that develop from buds on filamentous protonemata
• Have specialized cells for water and food conduction
  o Handrom (central strand) Leptom (surrounds hadrom)
  o Hydriods—transport water/minerals, are elongate cells with end walls , permeable to water , no living protoplasm (DEAD CELLS)
  o Leptoids—conduct sap (water +sugar), elongate cells with end walls, protoplast present at maturity but nucleus is degenerate (LIVING CELLS)
• Gametangia produced at tip of main axis/lateral branches
• Sporophytes born on female gametangia
  o Sporophyte grows, venter of archegonium enlarges = calyptra falls off, operculum open to expose peristome
• stomata

Question 9

Anthocerophyta (Hornworts)

Answer 9

• Resemble thallose liverworts
• Symbiotic relationship with cyanobacteria
• stomata

Question 10

MABS

Answer 10

MARCHANT–LIVERWORTS
ANTHO–HORNWORTS
BRYO–MOSS
SPAGNUM–MOSS