Lab Quiz 3 (lab 7: free-sporing plants) Flashcards
(29 cards)
What specialized structures does a liverwort have for gamete production?
gametangia: antheridiaphores and archegoniophores
(looking at beached thallus liverworts on display)
What are the openings in the epidermal layer and what is their function?
The openings are pores, and their function is gas exchange
(looking at gamma cups of liverworts)
Are the gemmae haploid or diploid?
Are gemmae the result of vegetative (clonal) or sexual reproduction?
Gemmae are haploid,
and are the result of vegetative reproduction
(moss life cycle)
What are the similarities with the liverwort life cycle?
Gametophyte dominant
(sporophytes of living moss)
What is the name of the structure that houses the spores?
The capsule houses the spores
(sporophytes of living moss)
What do the peristomal teeth do?
The peristomal teeth move back and forth depending on how moist or dry the conditions are.
When they dry out completely, they move the spores out forcefully dispersing them.
(sphagnum moss)
In what type of environment does Sphagnum grow?
Bogs / wetlands
(sphagnum moss)
Sphagnum had specialized dead cells that make it useful for hanging baskets and in potting media for many plants. What is the function of those dead cells?
The dead cells absorb and hold water
(lycopodium life cycle)
How does the alternation of generations differ from that of nonvascular plants?
Sporophyte dominant, bisexual gametophyte
(lycopodium life cycle)
What are strobili and where do they occur on the plant body?
Strobili: reduced spore-producing modified leaves (sporophylls) in a cluster at the tip of stems
(cross section of lycopod stem)
What type of stele does it possess?
Protostele
(resurrection plant)
Describe its roots and its overall morphology.
It has fibrous, adventitious roots and has a spreading flat form.
(resurrection plant)
How does its structure look different from when it is wet to when it is dry?
When dry it is curled up and brown,
when wet it spreads out flat and starts to green up with chlorophyll
(selaginella)
What type of branching does it have (is it dichotomous or does it have axillary buds)?
It has dichotomous branching
(leptosporangiate fern life cycle)
How does it differ from that of the lycopods and Selaginella?
Sporangia are clustered in sori on the underside of sporophylls instead of in strobili.
The gametophyte generation is very short-lived, and most are homosporous.
(leptosporangiate fern life cycle)
These ferns have colonies of nitrogen-fixing cyanobacteria that live in their leaves. Why do rice farmers have these ferns in their paddies?
The N-fixing bacteria in the leaves of the Azolla fix N from the atmosphere to make it available to the rice plants, especially when the Azolla die and decompose.
(Look at a sporangium)(technically synangia because they are made up of multiple fused sporangia).
How many parts are there to each synangium?
There are 3 fused sporangium to each synangium
(look at removed psilotum)
How do the rhizomes differ in appearance to the rest of the plant?
The rhizomes are thicker, brown and more irregular, while the rest of the plant is thinner, green and the stems are more uniform.
(cross section of the psilotum stem)
What type of stele do these plants have?
Protostele
(strobilus under a dissecting scope)
Can you identify individual sporangia?
yes
Now hold a few Equisetum stems in your hand. Are they rough or smooth?
Explain why the stem feels that way
The Equisetum stems are rough because they have silica in their cell walls.
lycopodiophyta have… which are?
microphylls which are one-unbranched vascular bundle
selaginella =
resurrection plant
resurrection plant unique characteristic
Poikilohydry: ability to loose 95% of their intracellular water and go dormant during dry seasons
