Lecture 13 - Seedless Vascular Plants Flashcards
What prevents desiccation?
Protective wall surrounding spores
What prevents evaporation?
Waxy cuticle
What do seedless vascular plants have for gas exchange?
Stomata
How is water and food conducted throughout the plant body?
Xylem and phloem
What do these plants have for support?
Lignin
Phenolic deposited in secondary cell wall does what?
Gives compressive strength and waterproofing
What are roots for in seedless vascular plants?
Roots for anchorage and water and mineral absorption
What generation is dominant in vascular plants?
Sporophyte dominant
What do more advanced vascular plants have?
A much reduced gametophyte
Most primitive vascular plants are?
Homosporous
What does homosporous mean?
Produce only one type of spore
Primitive vascular plants spores develop into:
Bisexual gametophytes
More advanced vascular plants are typically:
Heterosporous
Define heterosporous
Produce microspores and megaspores
Microspores develop into?
Male gametophytes
Megaspores develop into?
Female gametophytes
When were seedless vascular plants dominant?
~ 400-300 mya (from the Devonian to the Carboniferous periods)
What are the seedless vascular plants of today?
Ferns and fern allies
3 types included in lycophytes
Club moss, spike moss, quillwort
Another name for club moss
Lycopodium
Club mosses resemble large mosses but have what at their apex?
Have an elongate strobilus at their apex
Club Moss: Strobilus has ___________ that bear the sporangia
Sporophylls
What kind of sporous is lycopodium? Club moss
Homosporous
What is lycopodium’s (club moss) leaf type?
Leaves are microphylls
What does leaf type microphyll mean?
Small leaves that contain a single strand of vascular tissue
Another name for spike moss
Selaginella
What is Selaginella sporous type? spike moss
Heterosporous
Selaginella: where does the male gametophyte develop? spike moss
Inside the microspores
Selaginella: where does the female gametophyte develop? spike moss
Inside the megaspores
What’s another name for quillwort?
Isoetes
What type of plant is club moss?
Lycophyte
What type of plant is spike moss?
Lycophyte
What type of plant is quillwort?
Lycophyte
What is isoetes? quillwort
Small aquatic plant
Isoetes leaves resemble what? quillwort
Porcupine quills
Another name for whisk ferns?
Psilotum
Psilotum: describe leaves, roots, and branches
whisk ferns
No leaves or roots, dichotomously divided branches
Psilotum: where is sporangia produced? whisk ferns
At the ends of short lateral branches
Psilotum: what is whisk ferns sporous type? whisk ferns
Homosporous
Psilotum: what is the prothallus? whisk ferns
A nutritionally independent gametophyte
Psilotum: what does the prothallus produce? whisk ferns
Antheridia and archegonia
Psilotum: where do sperm swim from and to? whisk ferns
From antheridia to eggs inside archegonia
Psilotum: sperm is inside where? whisk ferns
Antheridia
Psilotum: eggs are inside where? whisk ferns
Archegonia
Psilotum: what does the diploid zygote develop into? whisk ferns
Develops into the sporophyte
Another name for horsetails?
Equisetum
horsetails Equisetum: the shoot is comprised of sections __________ ___ _________
Sections joined at nodes
Equisetum: what do sterile shoots have at each node? horsetails
Whorls of long, narrow leaves at each node
Equisetum: what does the fertile shoot lack? horsetails
Chlorophyll
Equisetum: the fertile shoot has a strobilus that bears what? horsetails
Sporangia
Equisetum: what do shoots have in their outer tissue? horsetails
Silica in outer tissue
What’s an important fact about ferns?
Largest group of seedless vascular plants
What is the most conspicuous generation of ferns?
Sporophyte
Most of fern stem is an?
Underground rhizome
What is the leaf type of ferns?
Megaphylls and often pinnately compound
What is on the underside of fern leaves?
Sori
In ferns, each sorus consists of what?
Many sporangia
ferns: within each sporangium, what do spore mother mother cells undergo and produce?
Undergo meiosis, produce four haploid spores
ferns: what do sporangia have a layer of?
Unevenly thick walled cells called annulus
How do ferns expel spores?
Humidity drops, sporangium cracks, annulus snaps back and expels spores
What are ferns sporous type?
Homosporous
When do fern spores germinate and what do they grow into?
In moist location, grow into gametophyte
Describe fern gametophytes shape and sexuality
Heart-shaped, bisexual
Another name for fern gametophytes
Prothalli
What is one trait of fern prothalli?
Photosynthetic
What anchors the fern gametophyte?
Rhizoids
Where is archegonia in ferns?
On underside of prothalus at notched end
A single ________ is produced in each archegonium
Egg
Where are antheridia found in ferns?
On underside of prothallus but are scattered at The apex
What do fern antheridia contain?
Sperm
Where do fern sperm swim to start fertilization? Where do they fertilize?
Swim to archegonia, usually fertilize a different prothallus
ferns: what develops after fertilization?
A new diploid sporophyte
ferns: what develops a foot that penetrates the prothallus?
Embryo
ferns: what does the sporophyte use the gametophyte for?
For nourishment until it becomes self-sufficient