Plants Flashcards
What are Micorrhizae?
Symbiotic partnership of fungi with angiosperms to get nutrients from soil. Fungi provides plants with additional moisture and nutrients. Plant provides sugars to fungi.
What are Mycelia?
Fruiting body made up of thin hyphae. Retains high amounts of moisture.
What are Basidia?
Specialized end cells of mushroom gills. Form spores during sexual reproduction.
Monophyletic
Group that evolved from common ancestor and includes all descendants of that common ancestor.
Sister group
Two groups that splits from common node in phylogeny.
Four defining features of Fungi
- Structure
- Nutrition
- Reproduction
- Dispersal
Structure of Fungi
- cell walls made of chitin
- Single celled or made of filament
- No complex transport system
- Have mycelia- body is made up of thin hyphae, and have crosswalls called septa. These pack to form mushroom.
Advantage and disadvantage of Hyphae
Hyphae are long and thin: high surface area to volume ratio
However, this limits fungi to moist environments.
Fungi are main decomposers or what? Fungi are also a key component of what cycles?
- Main decomposers of cellulose and lignin
- Key in Carbon, Nitrogen, and phosphorus cycles
What is “most famous symbiosis”?
Lichens!
Fungi reproduction
Asexual: Fragmentation during haploid phase of vegetative spores
Sexual: Compatible individuals fuse mycelia together- this triggers basidia in gills top fuse together and form spores through meiosis. Spores spread and land and germinate.
Fungi/ Spore dispersal
Spores can withstand challenging conditions
Small size facilitates airborne dispersal
What are cordyceps
Spores that use animal dispersers- create “zombies”- grows fungi out of insect.
Are protists monophyletic?
NO- protists are paraphyletic
Capture of photosynthesis- what’s it called? Describe the steps
Endosymbiosis: eukaryotic protist “engulfed” a cyanobacterium containing a chloroplast.
Secondary endosymbiosis is when an second eukaryotes engulfs the first eukaryote. (4 membranes created)
Which photosynthesizers make the most O2?
Archaeplastids- (algaes)
Phytoplankton
- Blue green algae
- Unicellular
- Base of almost every freshwater food web
Brown Algae
-Phoaphytes
-4 membraned chloroplast
-Multicellular
-Individual=thallus (filaments making up plant body)
Example: kelp (keystone species)
Relationship between kelp and otters
Otters lay in kelp- However they eat urchins which often disrupt the survival of kelp.
Kelp are primary producers in sea environment- so the urchin consumption by otters is vital to the ecosystem. (KEYSTONE SPECIES)
What is meant by alternation of generations? How come animals aren’t alternation of generations when they have both haploid and diploid phases?
Alternation between multicellular haploid and multicellular diploid. Gametophyte-Sporophyte. (plants)
Animals are diploid life cycle because their haploid phase is unicellular.
What is name of Fungi life cycle?
Fungi have a haploid life cycle
Red Algae- characteristics+ why is it red?
-Most diverse marine seaweed
-Helps build+ heal coral reefs
-Unicellular and multicellular
-Absorbs blue light (travels best through ocean)- giving it a red pigment (cartenoid).
Can live at great depths
Name for non-vascular plant vs. vascular plant
Non vascular plant: Bryophyte
Vascular plant: Traechyophyte
What are Viridiplantae?
The “green plant”
- Green algae
- Land plants (can be bryophytes or traecheophytes)
Dr.Bell’s experiment- what does it mean regarding rising carbon levels.
- With and increase of CO2 we have an Increase in primary production- will this decrease Carbon levels? Will increased photosynthesizers help offset human emissions?
- Experiment: grew a strain of chlamodyomonas in a high CO2 environment and another in an ambient CO2 environment.
- Results: Algae grown in high CO2 environment had lower CO2 uptake. This is because due to readily available CO2, there was no need for the algae to be able to uptake it efficiently.- No “forced mutation”.
Advantages of transition to land
- Large uncolonized area
- Abundant light
- Readily available CO2
- Less predators/ herbivory (at the time)
- Potential for symbiotic relationships
Challenges of initial transition to land
- UV radiation
- Dehydration
- Spore/ seed dispersal
- Gravity
- Nutrients
What is a cuticle?
Cuticle is Key innovation as results of UV ray damage on land.
Algae with cuticle and UV absorbing compounds were the plants that survived transition to land- “sun protection”
However, it inhibits gas exchange
What are the three major innovations of plants in order to reproduce on (dry) land?
- Sporopollenin: toughest biological material on earth that encases spores in order to allow them to resist drying and survive long periods.
- Gametangia: Specific male and female reproductive organs that prevent gametes from drying
- Embryo Retention: “plant pregnancy” Instead of shedding eggs, plants retain them; zygote begins development on parent plant.
5 Characteristics of Bryophytes
- No true roots (can grow on rocks)
- Can absorb through their “leaves”
- Small and slow growing
- Thin leaves with rudimentary cuticles
- Generally grows in damp habitats
Bryophyte reproduction
Can be unisexual or bisexual. Use spores for dispersal either way.
What moss has colonized land on every continent. How does it form?
Peat moss/bogs. Forms when plant material doesn’t fully decay in acidic and anaerobic conditions.
What challenges did Tracheophytes face post transition to land?
- Competition
- Colonized drier environment
- Get taller (for sunlight)
- Go deeper (access to nutrients)
What were the 4 main innovations of tracheophytes
- Branching: allows specific stems for different uses
- Stomata: tiny “holes” in cuticle on underside of leaf. Allows gas exchange.
- Vascular tissue: “get taller”. Xylem and Phloem provide structure and PUMP nutrients and water.
- Roots: Nutrient and water acquisition. (mycorrhizal fungi)
Vascular plants have a ________ dominant life cycle. This is because ______ cells respond to varying environmental conditions more efficiently.
Vascular plants have a SPOROPHYTE dominant life cycle. This is because DIPLOID cells respond to varying environmental conditions more efficiently.
What are our extant tracheophytes?
Clubmosses, ferns and horsetails
What are main Gymnosperms
Trees with seeds.
- Cycads (large cone at apex, eaten by dinosaurs!)
- Ginkgos (very resitant to pollution so often planted in cities- smelly)
- Conifers (most diverse gymnosperm, specialize in dry environments, thick bark)
- Gnetophytes
How is height an advantage?
- Access to light
- Shade out competitors
- Better wind dispersal
Definition of a tree
Plant with single stem and branching canopy that can reach large heights thanks to specialized cells. Has wood and increases in girth.
What were first tree like plants? When did they appear? How did they grow/ what was their structure?
Gilboa trees- mid devonian.
Made up of a bunch of “tiny trees”, not true wood. It was inefficient because it had many different xylem strands. Was outcompeted when real wood appeared.
Carboniferous Forests- what are they?
- Ancient fern forests covered in early tracheophytes.
- When the tracheophytes were outcompeted, they sank to the ground due to shallow roots. No lignin- decomposing- fungi were present. This resulted in TONS OF COAL.
Xylem vs. Phloem
- Xylem: water/ nutrients flow UP
- Phloem: sugars flow DOWN
What is the Vascular Cambium?
Ring of dividing cells beneath the bark in modern trees.
~Main growth tissue in gymnosperms and angiosperms
What is the “link between ferns and gymnosperms”
- Archeopteris. Now extinct
- Conifer wood with fern like leaves.
Reproduced via spores
What is heterospory? Why is it a key innovation?
- Spores now have two sizes. Two sexes.
- Megaspores: larger, female spores
-Microspores: smaller, male spores
This leads to evolution of seeds and pollen.
Evolution of seeds`
1) Creation of megagametophyte- megaspore
retained in sporangium while it germinates. It is
surrounded by integument, CREATION OF OVULE
-A fertilized ovule is a seed
Evolution of pollen
Microspores evolve into pollen grains (coated in sporopollenin) Swims down tube to ovule.
Can now survive dry habitats
What are Angiosperms?
- Flowers and fruits!
- By far largest amount of species of all land plants
Angiosperm radiation
When angiosperm lineages produces an unusually large amount of descendant species adaptive to many habitats.
3 Key adaptations of angiosperms
1) More efficient Xylem (ends of vessel has slits)
2) Fruits- enable transport or seeds
3) Flowers (reproductive organ- female carpels and male stamen)
What are ovary vs anther?
Ovules develop in ovary, pollen develops in anther
What is outcross pollination?
Pollen and stigma on different plants
*pollen that lands on wrong stigma is wasted
Significance of floral traits
- Attract pollinators
- Deter non-pollinating visitors
- Manipulate visitor behaviours to maximize pollen transfer (shape forcing towards stigma or anthers…)
Angiosperm radiation is associated with ______ in diversity and extent of _______________ relationships
Angiosperm radiation is associated with DECLINE in diversity and extent of PLANT- POLLINATOR relationships.
When do fruits ripen?
After fertilization
Monocots vs Dicots.
Who evolved from who?
- Monocots: 1 cotelydon, parallel leaf veins, petals in multiples of 3
- Dicots: 2 cotelydons, branching leaf veins, petals in multiples of 4 or 5
Monocots evolved from dicots
What are Eudicots?
“true dicots”
Monophyletic lineage that includes most plants considered to be dicots.
Difference between yeast and bacteria
Yeast has a membrane bound nucleus (eukaryote), bacteria doesn’t (prokaryote)
What are Saprophytes vs Symbionts
Saprophytes feed on dead decaying matter
Symbionts develop mutualistic relationships
What is a lichen made of?
Algae + Cyanobacteria
What is a dikaryotic mycelium?
The product of formation of two mycelia. This stage can last decades
Are land plants and algae mono or para- phyletic?
Mono
Do brown algae have a complex vascular system?
No
Sporophytes produce _____ by _____
Gametophyte produce ______ by _____
Sporophytes (2n) produce spores (n) by meiosis
Gametophyte produce gametes by mitosis
Why is red algae red?
There is Calcareous deposit in it’s cell walls
Absorbs blue light- appearing red
Red carotenoid pigment used in photosynthesis
How do chloroplasts get passed on to offspring?
