Kingdom Plantae Flashcards
Alternation of Generations
Two different life cycles.
Fertilization -> Sporophyte (2n) -> Meiosis -> Spore(n) -> Gametophyte(n) -> Mitosis -> Gametes(n) -> Fertilization
Gametophyte
Haploid generation that produces gametes through mitosis.
Sporophyte
Diploid generation that produces haploid spores through meiosis.
Gametangia
Gamete producing structures
Antheridia
Male, sperm-producing gametangia
Archegonia
Female, egg-producing gametangia
Sporangia
Produce haploid spores
Isomorphic Generations
Some algae.
Sporophyte and gametophyte generations look identical
Heteromorphic Generations
Land plants
Sporophyte and gametophyte generations look different.
Bryophytes
Descriptive, non-taxidermic category for plants belonging to three different Divisions.
Division Bryophyta, Anthocerophyta and Hepatophyta
Lack vascular tissue.
Dominance of gametophyte generation
Thought to have evolved from algae
Evolutionary dead-end
Unable to regulate water balance but can go dormant when exposed to drought.
Division Bryophyta
Mosses >14,000 species Mnium, Polytrichum, Sphagnum Have phyllids and caulids Monoecious and dioecious Contain rhizoids
Phyllids
Leaf-like structures spirally arranged on caulids
Caulids
Stem-like structures containing phyllids
Monoecious
Mnium
One house
Both antheridia and archegonia are present in same plant
Dioecious
Polyteichum
Two houses
Separate male and female gametophytes
Division Hepatophyta
Liverworts (Marchantia, Porella, Conocephalum, Riccia)
Simplest Bryophytes
> 9,000 species worldwide
Great diversity of body forms
Some contain phyllids and caulks
Contain rhizoids
Sperm have two flagella and require water to swim
Rhizoids
Anchor plant on its substrate, but do not conduct water and nutrients to the plant.
Not true roots, no vascular tissue
Division Anthocerophyta
Hornworts > 300 species Get name from long, hornlike sporangia Sporophyte gen. can outlive gametophyte gen. Have true stomata in epidermis
Seedless Vascular Plants
Contain true xylem and phloem Can control their water balance Have true roots that can absorb water Life cycles are dominated by sporophyte gen. Three Divisions
Xylem
True vascular tissue to distribute water from roots throughout the plant
Phloem
Distribute the products of photosynthesis to plant tissues
Division Lycophyta
Club Mosses (Selaginella, Lycopodium)
Moist environments (Selaginella also found in deserts, often called “resurrection plant”)
Often resemble small pine tress
Have true roots, stems and leaves
Club or cone-shaped sporangia on their stems called strobili.
Flagellated
Homospory and heterospory
Strobili
Clusters of spore-bearing leaves called sporophylls
Homospory
Spore mother cells undergo meiosis to produce one type of spore
Heterospory
When two different types of spores are produced.
Megaspores and microspores
Selaginella.
Megaspores
Larger spores that germinate to form female gametophytes
Microspores
Smaller spores that germinate to form male gametophytes
Division Sphenophyta
Horestails (Equisetum)
Only one genus and species remain
Huge tree-size reps. were common during age of Dinosaurs.
Strobili resemble tapered ends of horses’ tails
Cell walls contain silica
Often called “scouring rushes”
Division Pterophyta
Ferns
Whisk Ferns and Classic or “True” Ferns
Whisk Ferns
Psilotum
Sometimes divided into own Division (Psilophyta).
Very common in Florida
Very simple and primitive in appearance
May resemble very earliest vascular plants on Earth
Lack true roots
Usually participate in symbiotic relationship with fungus
Classic or “True” Ferns
Well represented in Florida > 12,000 species Some "resurrection ferns" Tree ferns can grow more than 60 feet in height, while smallest aquatic ferns can be 1 - 2 cm. Only group in which evolution appears to be ongoing Have true leaves called fronds Grow along underground rhizome Top of sporangium is hygroscopic.
Fronds
True leaves (mature)
Generally large, macrophylls.
Compound in form and divided.
One fertile frond can release millions of spores per year
Fiddlehead
True leaves (immature) Curled form of a young frond before unfurling
Rhizome
Horizontal stem
Can live for hundreds of years
Hygroscopic
Sensitive to the presence of water
