Bryophytes-Intro Flashcards
What are the 3 major groups of Bryophytes?
Liverworts (Marchantiophyta) previously Hepaticophyta
Hornworts (Anthocerotophyta)
Mosses (Bryophyta)
Which structure is the dominant structure in Bryophytes?
The gametophyte is the dominant structure. It is the leafy part of the plant. Gametophyte is haploid.
What medium is required for fertilization in Bryophytes?
Water is required for fertilization
What type of sperm does bryophytes have
Bi-flagellated sperm
How is Asexual reproduction carried out in Bryophytes?
By Fragmentation and Gemmae
Do Bryophytes have Plasmodesmata and Protonema?
Plasmodesmata present and Protonema common in most except hornworts
Which green algae is said to be the likely ancestor of Bryophytes?
Colochaete green algae
What are characteristics of Bryophyte?
In regards to:
1. Presence of embryo
2. Ancestor
3. Habitat
4. Component of thallus
5. Presence of Lignin or Cuticle
6. Absorption structure
7. Multicellular or Unicellular rhizoids?
8. Where is zygote stored till it develops into embryo?
- Produce an embryo- Embryophytes
- Evolved from green algae ancestors, related to charophytes
- Group of simple small land plants
- Grow in moist habitats
- Thallus made up of parenchymatous tissue
- Not filamentous
- Have no lignin, have cutin (cuticle) on plant/spores
- Have no roots, only filamentous rhizoids
- Have multicellular sex organs (enclosed in a sterile jacket)
- Retain zygote within the female sex organ to develop into embryo
Do Bryophytes have vascular tissue? How do they absorb nutrients?
- No, they lack vascular tissue (xylem & phloem).
- Lack true leaves and roots, have rhizoids instead.
- absorb water & nutrients by using rhizoids.
What are the two stages in the bryophyte life cycle?
- Gametophyte- dominant haploid stage
- Antheridia (male sex organ/flagellated sperm)
- Archegonia (female sex organ/ 1 egg as gamete) - Sporophyte- Unbranched diploid stage
- parasitic on gametophyte
- has a terminal sporangium, that produces spores after meiosis
- sporophyte releases spores that grow into protonema that develop into gametophytes.
What is poikilohydric photosynthesis?
Hydration is controlled by the environment.
Bryophytes are Poikilohydric.
What is Homohydric photosynthesis?
is a state of hydration controlled by internal mechanisms.
What type of life cycle do bryophytes exhibit?
Alternation of Generation
green, perennial gametophyte (N) & ephemerous dependent sporophyte (2N)
What do bryophytes require to reproduce sexually?
free water
Describe structure of gametangia?
composed of 1 or more sterile cell layers forming the wall; inside contains gametes.
