Flashcards in Chapter 30- Overview of Green Plants Deck (76):
What is a plant?
A multicellular, eukaryotic, terrestrial, photoautotroph
Land plants shared a common ancestor with what?
2 clades of green algae
Chlorophytes-never made it to land
Charophytes-sister to all land plants
Name a common Chlorophyte
What are chlorophytes
Unicellular green alae
Describe a few characteristics of volvox
Cells have 2 flagella
-asexual or sexual reproduction
What does haplodiplontic mean
alteration of generations between haploid and diploid stages
Plant adaptations for terrestrial life
Waxy cuticle and stomata
-water and other material movement using tracheids
-Shift to dominant diploid generation b/c of uv radiation
What are tracheophytes
They are plants that have tracheids
-Tracheids-xylem and phloem
Moss generation size?
Small, Dependent spororphyte
Angiosperm generation size?
Small, dependent gametophyte
Non vascular plants include what Phyla
Seedless vascular plants are what clade?
Seed plants are what clade?
gymnosperms and angiosperms
What are the main dispersal means of non seed plants?
What defines a Gymnosperm
A plant that produces seeds in a cone or at the tip of branches
What defines an Angiosperm
A plant that produces seeds that form in fruits
Describe a Nontracheophytic plant
Live in moist environments or close to water
-tend to be small
-Mycorrhizal associations important in enhancing water uptake
Are gametophytes haploid or diploid?
Are sporophytes haploid or diploid?
What do Nontracheophyte plants require for fertilization
water for sexual reproduction
Mosses are in what phylum
What does the gametophyte generation of Mosses look like
Small, leaflike structures around a stemlike axis
-not true leaves-no vascular tissue
What anchors mosses to their substrate?
What are the two types of gametangia in mosses
Archegonia and Antheridia
What are Archegonia
Female gametangia in Bryophytes-produces one egg (ovum)
What are antheridia
Male gametangia-produce many sperm
-flagellated sperm must swim in water
Liverworts are what phylum?
What defines Liverworts?
Look like mosses
-form gametangia in umbrella shaped structures
What makes Hornworts special
Sporophyte in photosynthetic
-cells have a single large chloroplast
-gametophyte is still dominant
Xylem does what?
Conducts water and dissolved upward from the roots
Phloem does what?
Conducts sucrose and hormones throughout the plant
What are 3 unique tracheophyte structures besides tracheids
Stems-support leaves and reproductive structures
Leaves-Increade surface area for photosynthesis
Roots-Provide transport and support
What defines Lycophytes?
-lack seeds (evergreens)
-Superficially resemble true mosses but the sporophyte is dominant
Besides mosses, what forms archegonia and antheridia
What do Pterophytes require for Sexual reproduction?
Water for their flagellated sperm
What is the most abundant group for seedless vascular plants?
What is the frond of a fern used for
Photosynthesis occurs here
What is a sorus?
a cluster of sporangia on the underside of certain fronds in ferns.
How are gametophytes formed from fern sporophytes?
2N spore mother cells within sporangium undergo meiosis to form 1N spores
Where do the antheridia and archegonia of ferns form?
In the prothalus, which is a product of mitosis of the 1N gametophyte spores
Describe some characteristics of Whisk Ferns
Found in tropics
-sporophyte consists of forking green stems w/o true leaves or roots
What is the defining characteristic of Horsetails
Sporophyte consists of ribbed, jointed photosynthetic stems.
What did seed plants first evolve from?
What is the evolutionary advantage of seed plants?
Seed protects and provides food for embryo
-Allows for waiting period for the conditions to be right
-Fruits enhance dispersal
All seeds have 3 of the following characteristics
1.) 2N multicellular, embryo plant
2.)Nutritive tissue, food source before photosynthesis begins
3.) Tough, protective seed coat
What is a seed
its the embryo, nutritive tissue and protective seed coat in one
What does heterosporous mean?
having two kinds of sporangia; spore mother cells and spores
What is the megasporangium?
It is the 2N female sporangium tissue. Divides by meitosis to produce 1N megaspores, which divide mitotically to produce egg that will combine with sperm to form zygote + tissues
What is the Microsporangia?
The 2N male sporangium tissue-found in male cones or anther of flowers
How do pollen grains form?
2N microspore mother cells undergo meiosis to form 1n Microspores, mitotic division makes 1N male gametophyte tissue-pollen grain
What are the 4 living groups of Gymnosperms?
What type of trees are conifers
Most familiar type
-pines, spruces, firs
Found in colder and drier regions of world
What type of leaves do conifers have
Thin and needle like
-most are evergreen-dont shed thier leaves
What does monoecious mean and what Phyla does it apply to
MEans separate male and female reproductive structures on the same tree (cones)
applies to conifers
What makes conifer leaves special
Leaves have thick cuticle and recessed stomata to retard water loss
What are Cycads
-Slow growing gymnosperms of tropical and subtropical regions
-resemble palm trees
What are Gnetophytes
Only gymnosperms with vessels in their xylem
What are Ginkophytes
Gymnosperm with one living species
What does Dioecious mean
Male and female reproductive structures form on different trees
What defines angiosperms
Plants with flowers and fruits; heterosporous
Ovules are enclosed in diploid tissue at time of pollination
What is a whorl
parts of a flower organized into circles
What is a pedicel?
The stalk of a flower from which other parts attach
What is the calyx?
Outermost whorl of a flower- made up of sepals (green leaves)
What is the corolla?
the second whorl of the flower-made of petals
What does the third whorl of a flower consist of
made up of the stamens
-each stamen has a pollen bearing anther and a filament
What is the innermost whirl of a flower made up of?
-consists of one or more carpels (stigma, style, ovule, ovary wall)
What are the levels (from outer to inner) of flower whorls?
third whirl (stamens)
Innermost whorl (female gametophyte)
What are the 3 major regions of the carpel?
What is the ovary in a flower
swollen base of a flower containing one or more ovules (where fertilization and seed formation occurs)
-ovary develops into a fruit
What is the stigma in a flower
The tip where pollen lands
what is the style in a flower
The neck or stalk inside the flower
How many megaspores does the mother cell produce in an angiosperm?
4 1N megaspores
-nucleus of remaining divides mitotically to produce 8 haploid nuclei
Where does pollen production occur in angiosperms?
in the anthers
-Diploid microspore mother cells undergo meiosis to produce 4 haploid microspores
-binucleate microspores become pollen grains
What do pollen grains develop into upon contact with flower
they develop into a pollen tube that is guided to the embryo sac
-One of the grains divides to produce 2 sperm cells