Unit 5: Taxonomy, Ecology, and Diversity Flashcards
What is mutualism?
Mutualism is a species interaction in which each species benefits by associating with the other.
What is obligate mutualism?
It means that the two species literally need each other, e.g. milkweeds and monarchs
What is mutual protection?
When the two species use each other for protection, e.g. the clown fish and anemone
What are competitive interactions?
Essentially, resource wars.
Since resources are scarce and limited, there is major competition for them.
In competitive interactions, which species wins?
No one, really; they are both “hurt” by the depletion of resources.
Which is usually more intense: inter-species or same-species competitive interactions?
Same-species
What is an ecological niche?
The environmental conditions under which an organism can survive and thrive.
What can we say about similar species and niches?
The more similar the niches of two species, the more intense the competition
What is resource partitioning?
The evolutionary process by which species adapt to share resources in a way that limits competition.
What is predation?
An species interaction in which one species (predator) captures, kills, and eats another species (prey).
What are the main three kinds of physical adaptations for prey that help with protection?
Warning coloration, mimicry, and camouflage.
What is herbivory?
When an animal feeds on plants
What two defences do plants have against herbivores?
- Tolerance + quick regrowth
- Physical or chemical deterrents
What is parasitism?
When one species (parasite) benefits by feeding on another (host), without immediately killing it
What do we call it when one egg-laying species benefits by having another raise its offspring?
Brood parasitism
What is brood parasitism?
When one egg-laying species benefits by having another raise its offspring, e.g. cuckoos or cowbirds
What are parasitoids?
Insects that lay eggs inside other insects
What is ecological succession?
A process in which one array of species replaces another
What is primary succession?
When NOTHING was there, e.g. new volcanic land or glaciers receding
What is a pioneer species?
The first species to appear in a primary succession, usually lichen or mosses
What do pioneer species do?
They are opportunistic colonizers that help to build and improve soils
What is a secondary succession?
When one array replaces another in a disturbed region, e.g. the OK Mtn Park fire
Who developed the taxonomic categories?
Carl Linnaeus
Our system of naming uses two names–what’s that called?
Binomial nomenclature
How are taxonomic names written?
A capitalized Genus, followed by a species epithet.
e.g. Ursus americanus
What is taxonomy?
The science of classification
What does classification mean?
Putting things in groups
What traits is our current system of taxonomy based on?
Morphological
What are morphological traits?
Physical and structural traits
What is the principle that Linnaeus’s system was based on?
It assumed that “more in common” meant “more closely related”
What is currently happening with the taxonomic system?
Many taxons are being reevaluated because modern DNA analyses are showing us that the original assumptions are, in fact, incorrect.
(think mammals vs. marsupials)
Where and when was Linnaeus?
Sweden, 1707-1778
Why are taxonomic names in Latin?
It’s a dead, unchanging language that scientists are already familiar with
Every organism has a unique _____ name.
Every organism has a unique species name.
How many known, living, and named species are there on Earth?
2 - 4.5 million
How many estimated species are there on Earth?
10 - 100 million
How many species is it estimated that we lose a year?
50 000
How is a species defined?
Organisms with similar characteristics that produce fertile offspring
A species is what?
The basic unit of biological classification.
What is the problem with our current definition of a species?
We run into problems with unicellulars that reproduce asexually.
What is a dichotomous key?
A key for the identification of organisms
What are the three domains?
Archaea, Eubacteria, Eukarya
What are the five kingdoms?
Monera, plantae, fungi, protista, animalia
How do lichens work as a pioneer species?
They literally create soil.
How do lichens create soil?
The lichen breaks down the rocks, producing organic materials; other stuff blows in, and soil is formed.
What are lichens?
A mutual relationship between fungi and algae/cynobacteria
What symbiotic interaction does lichen exemplify?
Obligate mutualism
How does the fungus benefit in the lichen relationship?
The algae and cynobacteria do photosynthesis, aka make sugars
How do the algae/cynobacteria benefit from the lichen relationship?
The fungi holds absorbs minerals from breaking down rocks; it also holds the water, because otherwise they would just dry up.
Where does most of a fungus exist?
Underground
What is the underground part of a fungus called?
The mycellium network
What does the mycellium do?
They look for molecules to break down.
Are fungi multi- or uni-cellular?
Mostly multi, but some uni (yeast)
Where do fungi live?
In warm,dark, moist conditions rich in organic matter
What is the point of fungi?
They are decomposers and can break down just about anything, i.e. wood, crops, plastic.
What are the benefits of fungi?
- They decompose and recycle nutrients
- Mycorrhiza helps trees and other plants absorb water and nutrients from the soil
- Lichens make soil
- Food: mushrooms and blue cheese
- Baking and brewing: yeast
- Antibiotics: penicillin
What are the negatives of fungi?
- Fungal crop parasites spoil food
- Mold damage to homes
- Parasites on humans, e.g. athlete’s foot
What is mycorrhiza?
It is a symbiotic relationship between fungi and the roots of vascular plants.
What do fungi get from mycorrhiza?
They get sugars (carbohydrates/energy) from the plants
What do plants get from mycorrhiza?
They gain nutrients and water from the soil
What are hyphae?
They are the long, branching filaments in the fungi underground network
What do hyphae do?
They search out and digest food
What are hyphae called as a collective?
Mycelium
How fast can hyphae grow?
Over 1 km/day
Where do hyphae come from?
They grow from a single spore (mitosis)
How do fungi do meiosis?
They hyphae become a fruiting body that then does haploid spore production
How do fungi break down food?
Externally; they secrete digestive enzymes onto food, then absorb the resulting small food molecules
What is a saprobe?
Mostly fungi and bacteria that obtain food from the decaying bodies of plants and animals
Give two examples of fungal parasites.
Athlete’s foot and ring worm
What phylum are club fungi?
Basidiomycota
What are some common species of club fungi?
Mushrooms, shelf fungi
What do club fungi do?
They decompose forest plants; they are the only fungus that can break down lignin (in plant stems)
What are basidiospores?
They are released from a club-shaped spore-producing structure called basidia
Describe the sexual phase of the fungal life cycle.
1. Dikaryotic stage (n + n) (fusion of nuclei) 2. Diploid (2n) zygote (meiosis) 3. Spore-producing structure (n) 4. Spores (n) 5. Haploid (n) mycelium (fusion of cytoplasm)
Back to #1!
What are the four major events in the evolution of land plants?
- Zygote protection and waxy cuticle
- Vascular tissue
- Pollen grain and seed
- Fruits and flowers
What are the two phases of a plant life cycle?
The diploid and haploid phases
What is the biggest difference between plants and animals?
Animals don’t have a diploid growth phase
Where are spores produced in fungi?
In the gills of the fruit
Flowers: What are the man bits?
The stamen.
The stamen produce sperm-pollen (male gametophytes) through meiosis in the pollen sack, which then go on to insert themselves in the centre tube (stigma).
Flowers: What are the lady bits?
The carpel.
The ovule lives inside the ovary at the base of the carpel; it undergoes meiosis, producing megaspores, which develop into a female gametophyte.
What does the female gametophyte include in flowers?
An egg and six other cells, include a cell with two nuclei.
What the hell is double fertilization?
One sperm fertilizes and egg to produce a zygote and another a diploid cell to create a triploid cell that develops into an endosperm; this makes a seed!
What the nut is an endosperm?
A triploid (3n) tissue in the seed that acts as food for the embryo; that’s what it’s more successful in new environments.
What plants are associated with the first major event in the evolution of land plants?
Bryophytes
What plants are associated with the second major event in the evolution of land plants?
Seedless vascular plants
What plants are associated with the third major event in the evolution of land plants?
Gymnosperms
What does bryophyte literally mean?
moss-plant
What does gymnosperm literally mean?
naked-seed
What plants are associated with the fourth major event in the evolution of land plants?
Angiosperms
What plants are bryophytes?
Mosses
What are the characteristics of bryophytes?
Short, no true leaves and no real roots; only found in moist habitats
Why doesn’t moss grow tall?
- It has no way of transporting water up and down
- It would fall over (no vascular tissue)
What stage is dominant in bryophytes?
Gametophyte
Why do bryophytes need moist environments?
It can only sexually reproduce in water; the sperm must “swim” to the egg
What plants are “seedless vascular plants”?
Ferns, horsetails, etc.
What are the characteristics of seedless vascular plants?
- has roots
- grows to over 30 cm
- stem walls show channels in cross-section
What do seedless vascular plants have in common with bryophytes?
Still cannot reproduce in dry environments
What kind of plants are gymnosperms?
Conifers
What are the characteristics of gymnosperms?
- Seeds!
- Pollen grains travel through the air from male to female structures and gametes meet after arrival (never exposed to air)
- Seed allows dispersal of protected embryo (increased survival rate of offspring)
How are seeds dispersed with gymnosperms?
Wind, gravity, and a few birds and animals
How is pollination achieved with gymnosperms?
Gravity and wind
What does angiosperm literally mean?
vessel-seed
What kind of plants are angiosperms?
Mapes, roses, dandelions, etc.
This is by FAR the most diverse group.
What is the point of fruit?
A fruit covering protects seeds and attracts animals; animals eating fruits disperse seeds in the feces
What is the point of flowers?
The colours and nectar attract insect and bird pollinators who carry pollen grains along as they travel from one flower to the next, effecting pollination
Flower parts: What’s the peener/tube part called?
Carpel
Flower parts: The thing that looks like a petal but isn’t
Sepal
Flower parts: Hole at the top of the carple
Stigma
Flower parts: Tube of the carpel
Style
Flower parts: Tank of the carpel
Ovary
Flower parts: Eggy bits
Ovule
Flower parts: Stem of the stamen
Filament
Flower parts: Pollen sack of the stamen
Anther
What’s a sporophyte?
Diploid, spore-producing body in the life cycle of land plants and some algae
Explain algae and sporophyte
Algae mostly have haploid gametophyte bodies (male and female different bodies), but then that little flowery-not-flower bit comes out, which is the diploid sporophyte part, and babies get made
Explain the plant life-cycle.
Top and clockwise:
Diploid phase
1. Multicelled sporophyte
(undergoes meiosis on the left; dotted line)
Now in the haploid phase 2. Spores (mitosis) 3. Multicelled gametophyte (mitosis) 4. Gametes
(fertilization on the right; dotted line)
Diploid again
5. Zygote
(mitosis)
Multicelled sporophyte!
