U3 T1 Flashcards
What are the 3 classification methods?
- Physical features: hair, fur, feathers
- Method of reproduction: sexual, asexual
- Molecular sequences: DNA
Why do we need classification?
So that organisations all around the world recognise animals with the same scientific name
What is Taxonomy?
The organisation of organisms in hierarchical groups known as a taxa eg. kingdom. the full hierarchy is known as a taxon
What is the order of taxon from least specific to most specific?
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
(Donkey Kong Plays Cocomelon On Fridays Good Stuff)
How many domains are there?
3
What are the three domains?
Bacteria, Archaea, Eukarya
What is the Binomial naming system?
Uses the Latin Genus and species names. often in italics where the Genus comes before the species and is capitalised. eg Canis latrans where Canis is the genus and latrans is the species.
Why are multiple definitions of species required?
Traditionally, differences in morphology was used to differentiate organisms where the ability to breed was also incorporated. there are many exceptions.
What is the most widely accepted definition?
A species is a group of organisms that have the ability to mate with one another to produce healthy, viable and fertile offspring.
What is an interspecific hybrid and give an example.
When organisms of different species can mate and produce healthy offspring but the offspring are not fertile. eg A horse and a donkey can mate to produce a mule.
Why do interspecific hybrids occur?
When closely related species are kept together in captivity rather than natural habitats
How many Kingdoms are there?
5 (You do not need to know the names of them)
What is sexual reproduction?
2 Parents with variation (Humans)
What is asexual reproduction?
1 parent with no variation (Bacteria)
What is an r-strategist?
- Short lifespan
- reproduce once in lifetime in large number
- short gestation period
- quick to mature
- little to no parental care or investment
- often live in hostile environments
- eg rats
What is a K-strategist
- long lifespan
- long gestation period
- can reproduce multiple times in lifespan
- fewer offspring
- more energy to nurture
- large amount of parental care or investment
- live in stable environments
- eg Elephants
What is classification by molecular sequences?
Linnaean system was based on morphological characteristics however, once evolutionary theory was accepted, biologists started analysing genetic sequences and comparing them - phylogeny.
Phylogenetics use this data to classify evolutionary relatedness.
What are the 4 species interactions that can be used to classify organisms?
- Predation
- Competition
- Symbiosis
- Disease
Explain the predation interaction
A predator prey relationship involves a predator and its prey. Prey numbers regulate predator numbers however the presence of predators can affect ecosystem dynamics.
Explain the competition interaction
Exists when organisms in an ecosystem use the same resources such as food, space, mates, nesting sites. negatively affects both participants
Explain the symbiosis interaction (3 forms)
Exist between species when at least one member benefits.
- Mutualism (Both Benefit)
- Commensalism (One benefits and other is unaffected)
- Parasitism (one benefits and other is harmed)
Explain the disease interaction
Involves harm to a living thing and can involve the interaction between a pathogen and a host.
Give an example of Mutualism and explain the relationship
Clownfish and Sea anemone. Clownfish help ward off other fish and also provide the anemone with nutrients. The anemone also provides protection for the clownfish.
Give and example of Commensalism and explain the relationship
Sucker fish on sharks. The fish get a free ride but the shark receives nothing in return but is also unharmed.
Give an example of parasitism and explain the relationship
Mosquitoes suck the blood of animals for protein to produce eggs while the animals are harmed in this process as they lose resources.
What is used as molecular evidence?
Similar proteins or DNA sequences
What is a clade?
An ancestor and all of its descendants
What is a phylogenetic tree?
A cladistic graph… but it has dates and does not need to bifurcate and does not need to be rooted
What are the three assumptions of cladistics?
- Common ancestry: assumes organisms in a group are descended from a common ancestor.
- Bifurcation: when organisms differentiate, they split into 2
- Physical Change: Cladistics assumes that physicals change occurs over time.
What is an ecosystem?
A biological community of interacting organisms and their physical environment. Habitats can include:
- Micro habitats - eg Bacteria in sweat glands.
- Ecoregions are ecosystems covering large biogeographical areas
What are old growth forests?
Ecologically mature forests that provide important habitats for many endangered species.
What is a healthy soil and what are its benefits
Have a high biodiversity (bacteria, earthworms and microbes)
promotes health in plants, animals and humans. can aslo recover from stress and assist in nutrient cycling.
What is the importance of coral reefs?
Supports many fish, invertebrate, plants, turtles, birds and marine animals. they protect coastlines from erosion and provide jobs and recreation.
give an example of an interspecific hybrid that does not produce fertile offspring
mule, liger, equus, mulus
what is stratified sampling
the breaking down of a large population into similar subgroups (strata) and collect random samples to represent the population
what are examples of strata in a forest ecosystem
canopy, trunk, leaf litter, etc
what is the purpose of stratified sampling
to make estimates about the population as a whole.
for example:
population density
distribution
affect of abiotic factors (e.g. altitude)
zonation (distance of beach from mangrove forest)
stratification (vertical zones: forest floor to canopy)
how must site selection be used for stratified sampling
selected from each strata that represent larger population
randomisation used to reduce selection bias
ensure adequate number of samples
when sites are placed, should be clearly marked and location recorded so further surveys can determine change over time
what are the types of surveying techniques and when should they be used
transects (line and belt): measure changes in distribution and abiotic factors over large areas
quadrats: measure density
what are the ways to reduce bias in stratified sampling
-large sample sizes
-use random number generators to pick coordinates for quadrat and transect placements
-clear criteria for counting organisms (minimum height, etc.)
-regular calibration of equipment
how should data be presented for stratified sampling?
-comprehensive as you may be unable to return to an area
-headings used for table determined by ecosystem type and aim of your study
- scale drawings of the profile (side view) of the vegetation along a transect
-appropriate graphical representations (e.g. scatter plot graphs)
what is biodiversity?
biodiversity is the variety of organisms living within an ecosystem, including the diversity of ecosystems
what are the types of biodiversity
genetic-variety of variations in a gene pool
species-variety of species in an ecosystem
ecosystem-variety of ecosystems and habitats in a region or biome
how do environmental factors affect distribution in an ecosystem
species have a set of environmental conditions that they need to survive, and distribution is determined by these factors.
what are some environmental factors limiting distribution
-climate (temperature, wind direction, salinity, etc)
-soil
-water quality
-air quality
how is percentage cover estimated
estimating the percentage of each quadrat covered by a species by breaking it up into a smaller grid and determining how to count squares that are only partially covered (e.g. over 50%)
how is percentage frequency calculated
quadrats are randomly selected and the number of quadrats containing the species is divided by the total number of quadrats taken
what is species richness
the number of species in an area
does not include the populations of each species or their distribution
what is species abundance
the number of a species in the ecosystem
what is species evenness
the number of individuals of a species in relation to the total number of individuals of all species in the area
what is used to calculate species evenness
shannon-wiener index (U3 T1 - 07 - calculating diversity)
what is used to calculate species diversity
simpson’s diversity index (U3 T1 07 - calculating diversity)
0 - monoculture (one species)
1 - infinity diversity
across which scales can ecosystems be compared
spatial and temporal
space and time
