Plants Flashcards
What are the 4 main groups of plants?
1- Charophytes
2- non-vascular seedless
3- vascular seedless
4- vascular seed
What are non-vascular seedless plants? 3 examples
Bryophytes
Liverworts, hornworts, and mosses
What are the 2 types of vascular seed plants? 3 exampls for each
Lycophtes - club mosses, quillworts, spike mosses
Pterophytes - whisk ferns, horsetails, ferns
What are the 2 vascular seed plants?
Gymnosperms
Angiosperms
What are Charophytes? What are they most closely related to?
algae
Closely related to land plants
What are 3 features that distinguish land parts? What 2 sea “plants” fit in with these?
Multicellular, eukaryotic and photosynthetic autotrophs
Red and brown seaweeds
Land plants also have what in their cell? (3) what is this the same as?
Cell walls, chlorophyll a and b in their chloroplasts
Same as serval algae groups
What 2 features does land plants share with their closet group the Charophytes?
1- both have plasma membrane containing rosette cellulose-synthesizing complexes for the cellulose within the cell walls
2- both have peroxisomes = enzyme minimizes the loss of organic products due to photorespiration
What is the last thing that connects land plants and Charophytes in the life cycles?
Flagellated sperm cells
What are the 5 things that have allowed land plants to diversify out from Charophytes since conquering land?
1- apical meristems 2- multicellular embryos 3- alternation of generations 4- sporangia producing walled spores 5- gametangia producing gametes
What is apical meristem?
Localized regions of cell division at tips of shoots and roots
What does it mean to have multicellular embryos? (4)
They develop from zygotes
that are retained within tissue of female plant
which provides nutrients
with specialized placental transfer cells
What life cycle do all land plants shows?
Alternation of generation
Where else does alternation of generation occur? Where doesn’t it happen?
Happens in green algae
Doesn’t happen in Charophytes (type of algae closest related to land plants)
Explain the 6 stages of alternation of generation
Diploid sporophyte
Undergoes meiosis to produce haploid spores
Spores undergo mitosis to get haploid gametophyte
Gametophyte through mitosis produces haploid gametes
Fertilization or 2 gametes produces diploid zygote
Zygote goes through mitosis to get diploid sporophyte
What are the spores produced by a sporophyte covered in?
Sporopollenin = durable organic material
As we move into more complex alteration of generation life cycles, what grows on the sporophytes that specifically produces the spores?
Sporangia = diploid spore mother cells undergo meiosis to get haploid spores
As we move into more complex alteration of generation life cycles, what grows on the gametophyte that specifically produces the gametes? Which 3 do we see this in?
Gametangia
In bryophytes, pteridophytes, and gymnosperms
What are the 2 types of gametangia called?
Female = archegonium producing single egg Male = antheridium producing many sperm cells
The 3 types of bryophytes are liverworts, hornworts and mosses. What are their phylums?
Liverworts = Hepatophyta Hornworts = Anthocerophyta Mosses = Bryophyta
What is the dominate stage in bryophytes?
Gametophyte stage
Explain the characteristics gametophytes stage in bryophytes (called)
Mass of green, branched, one-cell-thick filament = called protonema
Explain the bryophyte life cycle (7)
Male haploid gametophyte - top antheridia with haploid sperm
Female haploid gametophyte - top archegonia with haploid egg
Sperm gets dispersed by water over to archegonia
Fertilization occurs in archegonia = diploid zygote
Mitosis grows diploid sporophyte out of archegonia
Tip of sporophyte is sporangia undergo meiosis for haploid spores
Spores are released and through mitosis grow into male/female gametophytes
How are bryophytes anchored into ground?
With rhizoids = not the same as roots
Due to bryophytes being non-vascular, what do they lack? What does this mean (2)?
Lack xylem = can’t distribute water and have supporting tissues
What are the 2 phylums of the vascular seedless plants lycophytes and pterophytes?
Lycophytes = club mosses, quillworts, spike mosses = phylum Lycophyta Pterophytes = which ferns, horsetails, ferns = phylum Pterophyta
What is the dominant stage in vascular seedless plants?
Sporophyte is dominant
What is seen in the more evolved group seedless vascular land plants (spores)?
Homosporous = all spores same size and contain both antheridium and archegonium vs. Heterosporous = differentiation in sexes on spores
What is the sporangia grow on the sporophyte on ferns called? Where are they found?
Cluster called sori found on underside of the green leaves = sporophylls
Explain the life cycle of a fern as a Pterophyte seedless vascular plant (8)
Diploid sporophyte have sori
Each sori has a sporangia
Inside sporangia undergoes meiosis = haploid spores
Spores are released to grow into young haploid gametophyte
Mature gametophyte has antheridia w/ sperm and archegonia w/ egg
Sperm is released and swims to egg
Fertilization happens w/in archegonia = diploid zygote
Mitosis grow new diploid sporophyte from haploid gametophyte
If heterosporous allows for differentiation of sexes on spores, what does this mean?
Megasporangia produces Megaspores = develop into female gametophyte
Microsporangia produces Mircospores = develop into male gametophyte
Explain the life cycle of selanginella a lycophyte seedless vascular plant (8)
Diploid sporophyte grows strobilus
Strobilus has micro/megasporophyll w/ micro/megasporangia
Micro/megasporangia undergo meiosis to get haploid micro/megaspores = released
Microspores develop microgametophyte w/ antheridia w/ sperm
Megaspores develop megagametophyte w/ archegonia w/ egg
Sperm released and fertilizes egg = diploid zygote
Zygote through mitosis = diploid mature gametophyte
Grows into diploid sporophyte
Where are seedless vascular plants most common? Similar to what?
Is damp habitats like non-vascular plants
What does gymnosperm mean?
“Naked seeds” - ovules and seeds develop on the surfaces of sporophylls
What are the 4 phylums of gymnosperms?
Ginkophyta
Cycadophyta
Gnetophyta
Coniferophyta
What are the 3 adaptations of a pine as a gymnosperm of vascular seed plants?
1- sporophyte stage increases in dominance
2- seeds has resistant, dispersal stage
3- pollen dispersed by air
Explain the life cycle of a pine tree (10)
Diploid sporophyte grows ovule cone and pollen cone
Pollen cone has microsporophyll w/ microsporangia
Microsporangia undergoes meiosis to produce haploid microspores
Ovule cone has megasporophyll w/ megasporangia
Megasporangia undergoes meiosis to produce haploid megaspores
Inside megaspores is archegonia w/ egg
When microspores are related then become pollen grains
Pollination = sperm from pollen moves down to egg in archegonia
Fertilization = diploid embryo surrounded by haploid female gametophyte w/ diploid parent sporophyte = seed
Mitosis forms diploid seedling which grows into diploid sporophyte
How does pollination occur in gymnosperms?
By wind or animals
There are 4 megaspores produced in a megasporangium. Do they all survive?
No only 1 out of the 4 per each megasporangium will survive
Explain pollination in gymnosperms
When pollen lands on megasporangia and a pollen tube has developed from one of the sperm cells in pollen
Explain fertilization in gymnosperms
When the sperm and egg finally fuse inside the archegonia
Explain a seed in gymnosperm
Diploid zygote surrounded by the nutritive tissue of haploid female gametophyte still inside the original diploid female sporophyte
What is the male gametophyte of gymnosperms?
Is the same as pollen gains
What are angiosperms known as?
Flowering plants
What is the phylum of angiosperms?
Anthophyta
What are the 2 main classes of angiosperms?
Monocots and dicots
Explain the flower of an angiosperm
Specialized shoot w/ 4 circles of modified leaves called whorls
These are sepals, petals, stamen, and carpals
What is the stamen as a whorl of an angiosperm flower? What 2 things does it consist of?
Male reproductive organs = sporophyll that produces microspores which will grow into male gametophyte
Consists of = stalk (filament) and sac (anther) where pollen is produced
What is the carpals as a whorl of an angiosperm flower? What 3 things does it consist of?
Female sporophyll that produces megaspores that produces the female gametophyte
Consist of = tip a sticky stigma that receives pollen, style that leads to the ovary, which is at base of carpal and holds the ovules and later seeds
What is a fruit of an angiosperm?
A mature ovary developed from seeds that are fertilized ovules
Describe how a fruit is made
After pollination wall of ovary becomes pericarp = thicken wall of fruit. Other parts of flower wither away
What are the 3 classifications of fruits?
1- simple = single flower with single ovary
2- aggregate = single flower multiple ovaries
3- multiple = multiple flowers each with own ovary
What is an example of the 3 classifications of fruits?
Simple = cherry our soybean pod Aggregate = blackberry Multiple = pineapple
Explain the male gametophyte of an angiosperm
Contained within pollen grain, which develops in the anther of the stamen
Explain the cells of a pollen grain of an angiosperm
Only 2 haploid cells
Explain the ovules of an angiosperm
Contains the female gametophyte = embryo sac
Developed within ovary of the carpal
Explain the life cycle of an angiosperm (8)
Diploid flower (sporophyte) In anther (microsporangia) undergo meiosis = haploid microspores mitosis = pollen grain In ovary, the ovules (megasporangia) undergo meiosis = haploid megaspores mitosis = embryo sac (female gametophyte) Pollination = pollen grain released and land on stigma Double Fertilization = 2 sperm cell fertilize egg and polar nuclei cell Diploid zygote inside a triploid endosperm Seed = Embryo inside endosperm inside seed coat Germinated seed = seedling which matures into a flower
Although flowers can self-pollinate, what else must they be able to do?
Cross-pollination
Explain double fertilization in angiosperms
Once pollination has happened, the tube cell of the pollen grain will create a tribe for the generative cell (inside is 2 sperm cells) to go down and the 2 sperms cells will be released into the ovule and fertilize the egg and the polar nuclei cell
When the embryos of an angiosperm develops it has a root and 1 or 2 seed leaves. What are these leaves called and how can you tell the type of angiosperm form them?
Called cotyledons
Monocots have 1 cotyledon
Dicots have 2 cotyledons
What is coevolution? What reinforces it? What does it improve?
Mutual evolutionary influence between 2 species
Natural selection reinforces the interactions between the species
Helps to improve reproductive success for both
