Chapter 22 LAND PLANTS lecture Flashcards
Plant Ancestry and Diversity
Plants are ____ and ______
they adapted _____________
1.)multicellular eukaryotes
2.)primarily photosynthetic
adapted to life on land
land plants are close relatives of ___ and ___
like ALL green algae; they have ____ in their cell walls and ____ with what pigments…
PLANTS CONTAIN WHAT?
land plants are….
• Close relatives of RED ALGAE and GREEN ALGAE
• Like all green algae, plants contain:
- cellulose cell walls
-chloroplasts with chlorophylls a and b
-store sugars as starch
-Create a new cell wall via cell plate formation
during cell division
land plants shared traits ties them closely to ____
charophyte algae
Embryophytes
• Is the Defining trait of ____ _______
• EMBRYOS FORM WITHIN THE…
•Receive nourishment _____
- Defining trait of LAND PLANTS
- Embryos form within CHAMBER OF PARENTAL TISSUES
- Receive nourishment during development
All plants have alternation of generations that alternates between a ______ and a ________
- Diploid (sporophyte)
* Haploid (gametophyte)
DIPLOID:____
DIPLOID:sporophyte
HAPLOID:_____
HAPLOID:gametophyte
Earliest plant fossils closely resemble______
ex:___________
bryophytes—-> (mosses, liverworts, hornworts)
Flower is ____
gametophyte stage of a sporophyte plant?
Alternation of Generations
1-5
• The diploid generation, the multicellular sporophyte,
produces haploid spores by meiosis
• Spores grow by mitosis to become the alternate
generation, the haploid gametophyte
• The gametophyte produces gametes by mitosis
• The gametes meet, and fertilization occurs to form a
diploid zygote
• The zygote grows by mitosis to become the next diploid sporophyte
Bryophytes examples
—liverworts, mosses, and hornworts
Bryophytes
- Gametophyte is larger and longer-lived than the sporophyte
- Nonvascular plants – do NOT contain transport tissues for nutrient transport
- Seedless, instead they produce spores
- Vascular plants – contain tissues for transport of water and nutrients
- Sporophyte is larger and longer-lived than the gametophyte
• Some do not produce seeds, some do produce seeds
Ex:—liverworts, mosses, and hornworts
Seed-ed plants
• Vascular plants that hold on to their spores and disperse by releasing seeds
• Produce pollen
• Two lineages survive today
- Gymnosperms
- AngiospermsStory of plant evolution
Story of plant evolution
• Adapted to life on land
• Adapted to increasingly drier habitats
• Cuticle, Stomata, root systems, leaves and surface area
Sporophyte dominates all vascular plant life cycles—
- Spores more likely to survive in dry conditions
- Xylem and phloem
-Ex: Oak tree • Large and complex sporophyte (the tree) • Gametophyte: only a few cells
Evolutionary Trends Among Plants
Genetic factors——–
Structural adaptations———
Genetic factors——–
• Haploid vs. diploid
- As plants spread out onto drier habitats, they evolved features that allowed them to survive without being surrounded by water (vascular systems and seeds)
- Influenced diploid sporophyte dominance
Structural adaptations———
• Cuticle=Helps reduce evaporative water loss
• Stomata= Open to allow gas exchange for
photosynthesis, Close to conserve water
• Root systems=Thread-like underground parts specialized for absorption of water and minerals
Cuticle
Helps reduce evaporative water loss
Stomata
Open to allow gas exchange for
photosynthesis, Close to conserve water
Root systems
Thread-like underground parts specialized for absorption of water and minerals
Vascular tissues
- Internal system of pipelines
- Xylem distributes water
- Phloem distributes sugars
- Lignin in xylem provides structural support
Leaves
- Contain veins of vascular tissue
* Allow plant to capture sunlight and exchange gases
POLLEN GRAINS—>
SEEDS—->
Angiosperms disperse seeds inside a fruit
POLLEN GRAINS—> produced by seed plants are the walled, immature gametophyte
• Gives rise to male gametes
• Travel to female gametophytes on the wind or in insect bodies
• Allow plants to reproduce even in dry environments
SEEDS—-> protect the sporophyte embryo and nutritive tissue, enclosed within a waterproof seed coat
• Many have features that facilitate their dispersal
**Angiosperms disperse seeds inside a fruit
Bryophytes -
-
-
—— Phylum Bryophyta: Mosses——
Bryophytes -
• Includes mosses, liverworts, and hornworts
• All have a dominant gametophyte*
• Lack of vascular tissue keeps bryophytes small*
• Small size helps flagellated sperm reach the egg
• Often inhabit areas vascular plants could not grow
• Ex. Colonize rocky sites and harsh conditions where vascular plants cannot take root
• Some of the only plants found in the Arctic and Antarctic
—— Phylum Bryophyta: Mosses——
• Most diverse and familiar group of bryophytes
• Gametophyte is made up of leaflike thalli arranged around a central stalk, and thready, ROOTLIKE RHIZOIDS; both can absorb water and nutrients
Life Cycle of a moss:
1.
2.
3.
Life Cycle of a moss:
1. On the gametophyte, eggs and sperm develop in
gametangia at the shoot tips of the moss.
2. After fertilization, the zygote develops into a mature
sporophyte, which consists of a sporangium in which the spores develop
3. Spores are dispersed by the wind and develop into one or more gametophytes
- Mosses can also reproduce asexually via
fragmentation
Liverworts:Phylum ____________
Liverworts:Phylum Hepaticophyta
liverworts- - - - -
- Liverworts are in Phylum Hepaticophyta
- Among oldest known fossils of land plants
- Gametophytes of liverworts can be leafy liverworts
- Can reproduce asexually and sexually
• Asexual: gemmae cups on surface of thallus
• Sexual: male and female stalks grow up from thalli and produce
gametes
• Example: Marchantia
Hornworts in Phylum ___________
•
•
Hornworts in Phylum Anthocerotophyta
• Has a pointy, hornlike sporophyte
• Contain chloroplasts (unlike mosses or liverworts)
• Most of the SEEDLESS VASCULAR PLANTS that flourished in the past are extinct…
-
-
• Most of the SEEDLESS VASCULAR PLANTS that flourished in the past are extinct…
• **Present day descendants include lycophytes,
horsetails, and ferns
• **Differ from bryophytes with respect to the
sporophytes, which:
- Develop independently of the gametophytes - Have well-developed vascular tissues - Are the larger, longer-lived phase of the life cycle
• The spores of seedless vascular plants develop into tiny, short-lived, photosynthetic gametophytes that produce gametes
SEEDLESS VASCULAR PLANTS OVERVIEW
SEEDLESS VASCULAR PLANTS
• Oldest vascular plant lineages
• ***Disperse by releasing spores directly to the
environment
• ***Have flagellated sperm that swim to eggs
• Dominant sporophytes can be large and long-lived;
have true roots, stems, and leaves
• Two lineages survive today:
-Phylum Pterophyta – ferns, horsetails, and whisk ferns -Phylum Lycophyta (Lycophytes) – club mosses and spike mosses
SEEDLESS/VASCULAR PLANTS: Whisk ferns (not true ferns) - - -
Whisk ferns (not true ferns):
• Native to the Southeastern United States
• Sporophyte has rhizome, but no roots
• Leafless, photosynthetic stems
SEEDLESS/VASCULAR PLANTS: Horsetails
-
Horsetails:
• Only one remaining genus, Equisetum
• Sporophyte has hollow stems with whorls of leaves
• Deposits of silica in the cell walls of stems
(scouring rushes)
• Spores produced in sporangia clustered as a
strobilus
SEEDLESS/VASCULAR PLANTS: Club mosses -Most common is\_\_\_\_ - - -
-
-
Club mosses
• Most common: lycophyte
• Grow on the floor of temperate forests
• Resemble mini pine trees, sometimes called ground pine
• Sporophyte has true roots and stems with small leaves growing from a rhizome
- Ex: Lycopodium
- Sporophytes resemble small pine trees
- Spores produced on a strobilus
- Waxy coating on spores can be easily ignited when suspended in air
- Led to the use of spores as flash powder for photography and magic
SEEDLESS/VASCULAR PLANTS: FERNS - - - - -
SEEDLESS/VASCULAR PLANTS:
Ferns
• Most diverse and familiar seedless vascular plant
• Varied in size and shape
• Most live in the tropics
• Many are epiphytes – a plant that grows on other plants but are not parasitic
• Sporophyte has leaves called fronds and a horizontal stem called a rhizome from which roots grow
FERN Sporophyte has leaves called ______ and a horizontal stem called a ______ from which roots grow
- Fiddlehead is a _______
- Sorus – _____________
Sporophyte has leaves called fronds and a horizontal stem called a rhizome from which roots grow
- Fiddlehead is young frond
- Sorus – a cluster of sporangia on underside of frond; where spores are produced
Ferns
•
•
•
Ferns
• Fern spores form by meiosis in sori, which germinate
into small heart-shaped gametophytes
• Eggs and sperm form in the gametangia, which
release sperm when it rains
• A fertilized egg develops into a new sporophyte, and
the parental gametophyte dies
Advantages of seed-bearing plants: 1. Reproductive traits - - -
- ## Structural traits-
Advantages of seed-bearing plants:
1. Reproductive traits——-
• Gametophyte protected within sporophyte
- Microspores and megaspores produced (this means the gametophyte is not dependent on external conditions anymore)
- Seeds contain embryo and provide stored food wrapped in a protective seed coat
- Structural traits——-
• Secondary growth (increases diameter)
• Some produce wood made of lignin for strength and protection
Gymnosperms were the first seed plants to evolve
t or f
true
-
-
• Types- • • • •
Gymnosperms
• Vascular seed plants that produce “naked”
seeds
• “naked” refers to not having fruit around the seed
• Some may be in a paper or fleshy covering
• Types-
• Cycads
• Ginkgos
• Gnetophytes
• Conifers
-
-
Cycads
• Only about 130 species still exist – confined to tropics and subtropics
• Often resemble palms, though not closely related
• Flagellated sperm
CONIFERS---- - - - - -
CONIFERS—–
- Most diverse gymnosperm lineage (about 600 species)
- Trees and shrubs with woody cones
- Needle-like or scale-like leaves with a thick cuticle
- More resistant to drought and cold than flowering plants
- Evergreen
- Include the longest lived plants
- Some bristlecone pines are 4,000 years old
- Great economic importance
- Source of oils, bark mulch, and lumber
FLOWER:
-
-
Angiosperm Traits
• Vascular seed plants that make flowers and fruits (i.e.
seeds produced in fruits)
Flower————
• Contains sepals, petals, stamen, and carpel
• Innermost part of the flower is the ovary
• Double fertilization produces a seed from an ovule and endosperm (stored food)
• Ovary becomes the fruit
Angiosperm Diversity
Angiosperm Diversity————————
**90 percent of all species today are angiosperms*
• Angiosperm characteristics give them a selective
advantage over gymnosperms
• Shorter life cycle
• Most angiosperms develop rapidly and
produce seeds quicker than gymnosperms
Animal-pollinated flowers——————
• The development of flower leads to the attraction of insects, birds, and other
animals that helped reproduction occur rapidly
• Enhanced seed dispersal
• Monocots and eudicots have different characteristics—
• Monocots and eudicots have different
characteristics:
• Monocots and dicots derive their names from the number of seed leaves (cotelydons)
—— Monocots have one, dicots have two
- Vary in their leaf venation, arrangement of vascular tissue, and number of flower parts (petals)
- Unlike Dicots, monocots only undergo primary growth, meaning they get long or tall, but not thick. They do not produce true wood
why is it critical for ferns to live in a moist enviorment ?
ferns require water for fertilization
Unlike Dicots, monocots only undergo ______ growth,
meaning they get long or tall, but not thick. They do not produce true wood
Unlike Dicots, monocots only undergo PRIMARY growth, meaning they get long or tall, but not thick. They do not produce true wood
most of the fruits and vegetables we eat are…
eudicots/ dicots
what structure grows from a true fern spore upon germination
prothallus
what group of plants are commonly called sago palms and used locally for landscaping
cycads
which plants were the first to have true leaves and roots in addition to true stems…
club mosses*
Phylum- lycophyta
Lycopodium
what does the term dioecious mean
separate male and female plants
which of the following characteristics describes a monocot SELECT ALL THAT APPLY
- petals in 4s and 5s
- petals in 3’s
- fibrous root system
- taproot system
petals in 3s
fibrous root system
what were the first plants to have pollen
gymnosperms
which of the following is TRUE about nonvascular plants ?
a-they reproduce w/ seeds
b-they can grow to greats heights due to water and nutrient transport efficiency
c-they have a gametophyte-dominant lifecycle
d-they have roots
e- non-vasuclar plants all have the same phylum
c-they have a gametophyte-dominant lifecycle
Alternation of generations
diploid gen. MEIOSIS=haploid spores–>spores–> MITOSIS —> gameto gen. —>makes gametes by MITOSIS—>the gametes meet, fertilization=
=DIPLOID ZYGOTE—> zygote grows by MITOSIS—–> becomes next diploid sporophyte
