Unit 3 Topic 1 Flashcards
What is classification?
Classificationis the systematic and rationalgrouping of both organisms andecosystemsto show the biological relationships between them
What can classification be based on?
1) Similarity of physical features
2) Methods of reproduction
3) Molecular sequences
4) Species interaction
What is the taxonomic order/rank?
Domain, Kingdom, Phylum, Class, Order, Family, Genus (e.g Pseudomys), Species (e.g Plains Mouse).
Dear King Phillip Came over for good soup
What is the definition of a species?
A species is a group of organisms that can potentially interbreed, or mate, with one another to produce viable, fertile offspring.
What is an interspecific hybrid, and an example of one?
The offspring are not viable (infertile) andcan’t reproduce. Example is a mule.
Why is multiple definitions of a species needed?
Multiple definitions of species are required because some species definitions/concepts cannot be applied to organisms that do not reproduce sexually.
Describe features of the Linnaean system of classification?
Starts more broadly and gets specific
Features 3 differents domains
Utilises bionomial nomenclature
Grouped on similarity of physical features
What is the Linnaean system of classification based off of?
Based on similarities in obvious physical traits.
Describe the two methods of reproduction?
Sexual – 2 parents with variation (e.g. humans)
Asexual – 1 parent with no variation (e.g. bacteria)
What are the two types of reproductive selection?
r-strategists – short life-span, high rate of reproduction, quick to mature, little care for offspring (e.g. insects)
K-strategists – fewer offspring, more energy to nurture,higher survival rate,longer gestation period (e.g. chimp)
What is the word for classification by molecular sequences?
Phylogenetics
What is phylogeny?
The process of comparing geneticsequences and molecularstructures.
What is cladistics?
When similarities in molecularsequence is used to define agroup of organisms.
What does a phylogenic tree show?
A phylogenetic tree shows patterns based on morphological or genetic sequences
What is predation? (Classification by Species interaction)
A predator-prey relationship involves a predator and its prey. Prey numbers regulate predator numbers, but the presence of predators can impact ecosystem dynamics
What is competition? (Classification by Species interaction)
A competition relationship exists when organisms in an ecosystem use the same resources – e.g. food, space, mates, nesting sites
This relationship negatively affects both participants
What is symbiosis and what are the 3 types? (Classification by Species interaction)
interaction between two different organisms living in close physical association, where at least one species benefits
What is disease? (Classification by Species interaction)
Disease involves the harm to a living thing and can involve the interaction between a pathogen and a host
Disease can be classified asinfectious or non-infectious, involve pathogens, parasites, vectors/hosts
What molecular evidence is used for classification and as evidenceof relatedness betweenspecies?
Amino acid and DNAsequences
If two species have similar proteins or DNA sequences it is usedas molecular evidence that they shared?
A recent common ancestor
What do organisms that share a common ancestor have fewer differences in?
Their amino acid sequences
What will happen if two populations become isolated?
Theywill accumulate differences (mutations) in their DNAsequences over time
The rateof accumulation of mutations can be used to calculate?
Howlong-ago organisms diverged
The greater the difference in the DNA sequences between two species…
The more time is inferred to have passed since they shared a common ancestor
What are the common assumptions of cladistics?
Common ancestry:
Cladistics assumes that organisms within a group are descended from a common ancestor
Bifurcation:
Cladistics assumes that there is a bifurcating pattern (dividing a branch into two)
Physical change:
Cladistics assumes that physical change occurs over time
What is the difference between a phylogram and a cladeogram?
Phylograms (phylogenetic trees) have branch lengths proportional to the amount of evolutionary time and are a more accurate representation of the evolutionary history of an organism
Cladograms are more simplistic, giving a hypothetical picture of the evolution of organisms with no time-scale
Clade refers to?
A clade is a group oforganisms that includes anancestor and all theproposed descendants ofthat ancestor, also called amonophyletic group
What is an ecosystem?
An ecosystemis a biological community of interacting organisms and their physical environment
Why is it important to classify ecosystems?
Classifying different ecosystems is vital for ecosystem management and conservation
Why are old growth forests important to classify?
They provide important habitat for many threatened species, and have diverse structures and a mix of species and often contain old trees with hollows
Why are productive soils important to classify?
Soils can have high biodiversity, including bacteria, fungi, earthworms and termites. Healthy soil has biological, physical and chemical propertiesthat promote the health of plants, animals and humans, can recover from stress and can assist in nutrient cycling which supports plant growth, decomposition and promotes healthy growth.
Why are coral reefs important to classify?
Coral reefs support a huge number of fish, invertebrate, plants, turtles, birds and marine mammals. They protect coastlines from storms and erosion, provide jobs and recreation and hold cultural significanceto indigenous people around the world
What is the 3 step method used to classify ecosystem in Queensland?
- Bioregion (there are 13)
- Landform (there are 12)
- Vegetation community (there are 185)
What does stratified sampling involve?
Stratified sampling breaks a large population down into similar subgroups (strata) and collects random samples as a representation of the population
Why do ecologists employ stratified sampling?
Stratified sampling is conducted to make estimates about the population as a whole
These estimates could include:
Population density
Distribution
Environmental gradients/profiles (gradual changes in abiotic factors – e.g. effect of altitude)
Zonation (distribution of species into zones of different conditions – e.g. distance from the beach into a mangrove forest)
Stratification (distribution of species into different vertical zones – e.g. forest floor to the canopy)
Site selection involves?
Sites must be selected from each strata that are fairly homogenousand representative of the larger population.
Randomisation methods should be used to minimise selection bias. Thesurveyorsmust ensure an adequate number of samples,replicates within a sample and frequency of sample collection
Themain surveying techniques used are:
Transects to measure distribution
Quadrats to measure density
How do you minimize bias when sampling?
Greater number of samples = greater probability that thesamples are representative of the community
A grid overlay on the survey area where site selection isbased on a random number used to pick grid coordinates for transect or quadratplacement
Establishing clear parameters for counting organisms
Regular servicing and calibration of equipment and acknowledgment of precision
How do you present data?
Data collection should always becomprehensive as you might notbe able to easily return to an area
The headings you select for yourtable are determined by the typeof ecosystem being surveyed and the aim of your study
Profile diagrams are scaledrawings of the profile (sideview/elevation) of the vegetationalong a transect. These are usedto make qualitative
comparisonsbetween communities
Appropriate graphical representations are used to best visualize the data (e.g. scatterplots)
What is biodiversity?
Biodiversity is the variety of organismsliving within an ecosystem. It also includes the diversity of ecosystems
Why is it important to measure biodiversity?
Measuring biodiversityis important for determining the wellbeing of ecosystems, as higher levels ofbiodiversity help to stabilize ecosystems and deal with suddenchange
Ecologists measure biodiversity to assess ecosystem health, andconsider human practices that may be harming or helping inmaintaining biodiversity
What are the 3 levels biodiversity can be measured at?
Genetic: Variety of gene variations in the gene pool
Species: Variety of species present in an ecosystem
Ecosystem: Variety of ecosystems and habitats in a given region / biome
What is species diversity?
Species diversity is the numberof different species present inan ecosystem
Why does more habitats and microhabitats in an ecosystem increase the amount of species present?
Because each species has aset ofenvironmental conditions which are required for their survival called atolerance range. These environmental conditions limit the distribution and abundance of species
How does climate limit species distribution?
Climate includes precipitation, temperature, winddirection, cloud cover and sunshine which allaffect the type and abundance of species
Windaffects salinity in coastal areas, precipitation and plant transpiration
Warmer climates tend to support biodiversity whilecolder climates tend to reduce it, resulting inslowed metabolism and slow or sporadic growthof plants
This harshness means only few species can surviveand flourish,minimisingfood supplies, resulting inlimited biodiversity
How does soil affect species distribution?
Soils are formed when the underlying bedrock isweathered and broken down into grain-sizedparticles, so the underlying rock has a large influenceon which plants can grow in an area
The types of plants present will determine whichanimals can also live in an area
Soil quality includes the thickness, structure, porosity, pH, nutrient content and salinity
How does water quality affect species distribution?
Marine and fresh-water ecosystems depend on water quality
Measurable factors in aquatic environmentsinclude light, depth and turbidity (water clarity),oxygenation, temperature, pH, and water flow
What does percentage cover measure?
Percentage covermeasures the proportion of an area coveredby an organism to estimate abundance
What are the four ways to measure percentage cover?
Basal cover
Ground cover
Leaf/foliar cover
Canopy cover
What is species richness?
Species richness is a simple measure of the number of species within a particular area
What is species abundance?
Species abundance is the number of individuals of a particularspecies in the ecosystem under consideration
What is species evenness?
Species evenness (relative species abundance) is a measure of thenumber of individuals of a species in relation to the total number ofindividuals of all species in the area
