LESSON 3: Bryophytes Flashcards
What do bryophytes include?
Liverworts, hornworts and mosses
How are bryophytes similar to algae (4 reasons)?
1) Produce flagellated sperm that must swim through water to reach eggs
2) Lack of vascular tissue
3) The gametophyte (n) is much longer lived than the sporophyte (2n) and is photosynthetic
4) Sporophyte is permenantly associated with gametophyte (not independant)
What is a non-vascular plant?
A plant without vessels or tubes to transport materials from one place to another.
As colonizers of bare land with small bodies, what are their advantages (2)?
The small bodies trap particles of inorganic matter which
1) Helps to build soil on bare rock
2) Stabilizes soil surfaces
What does it mean for plants to be poikilohydric?
That they can’t prevent desiccation but can rehydrate.
True or False: Bryophytes are all poikilohydric?
True
How are bryophytes adapted to land (2 reasons)?
1) Their sporophytes (some species) have a water-conserving cuticule and stomata
2) They have rhizoids to anchor the plant to its substrate
What is a cuticule?
A waxy coating on the surface of a leaf (or other surface)
What are stomata? What is their purpose?
A stomata is made of 2 guard cells that create an opening in the epidermis. They are for gas exchange.
Do liverworts have stomata or something of the same type?
No, but they do have pores tant fulfill the same function.
How is called the simple body of liverworts? What alternation of generation element does it represent?
A thallus. It is the gametophyte generation.
In mosses, what happens after the spore germinates?
It elongates and branches into a filamentous web of tissue called protonema.
What are some characteristics of a protonema in mosses (2)?
1) It can become dense enough to color the surface of soil, rocks, or beak visibly green.
2) A single one can be very prolific, asexually producing bud after bud, thus giving rise to a dense clone of genetically identical gametophytes.
What structure is produced at the tip of a male gametophyte?
Antheridia
What structure is produced at the top of a female gametophyte?
Archegonia
What characteristic of sperms permits for them tonswim through a film or see of rainwater?
Flagella
How do hornworts differ from other nonvascular plants?
Their sporophytes can become indépendant of the gametophyte.
True or False: Hornworts are the group of bryophytes that have a more recent common ancestor with vascular plants.
True
True or False: The sporophytes of hornworts have stomata.
True
