Classification processes Flashcards
Advantages of Classification
- makes communication about living things much easier and more efficient
- allows easier analysis of the relationships between species
Hierachial classification
- domain
- kingdom
- phylum
- class
- order
- family
- genus
- species
Linnaeus naming system
Based on physical features:
Two epithets
- generic epithet
unique to that genus
- specific epithet
not necessarily unique as other species in different genera may have same specific epithet
Different types of Kingdoms
- animals
- plants
- fungi
- protists
- archaea
- bacteria
The 3 domains
- bacteria
- archaea
- eukarya
Dichotomous keys
Allow the identification of a species by dividing all possible species in two, etc, based on observable traits
Asexual reproduction
Advantages:
- does not require special cells or a lot of energy
- can produce offspring quickly
- in a stable environment creates large, thriving population
Disadvantages:
- limited ability to adapt
- faces massive die-off if environment changes
Sexual Reproduction - R
R-strategist
- r = growth rate
- high r value and low carrying capacity
- grows fast but most die due to density independent factors - climatic events, fires
Sexual reproduction - K
K-strategist
- low r and high K
- grows logarithmically - slow but more survive
- threats are density dependent factors - predation, competition
Advantages/Disadvantages of K
Ad:
- lots of variation within a species
- able to live in a variety of environment
- able to adapt to changes in the environment
Dis:
- needs time and energy
- produces small populations
What are the 4 types of species interactions?
Species Interactions
- predation
- competition
- symbiosis
- disease
What is predation
- any interaction between 2 organisms where the predator consumes another organism
What is competition?
- where both organisms are harmed
- when individuals compete for space/resources/mates etc.
- interspecific - competition between different species
- intraspecific - competition in the same species
What is symbiosis?
Mutualism:
- both species benefit
- anemome protects clownfish / clownfish provides faecal matter for food
Commensalism:
- one benefits / other is unaffected
- barnacles transported to plankton-rich waters by whales
Amensalism:
- one is destroyed/ other is unaffected
- fungi secreting penecillin
Parasitism:
- one benefits/ other is harmed
- ticks/fleas feed on the blood of canine host
What is disease?
Organisms can be classified based on their role in a disease
Parasite:
- organism which lives/feeds of host and causes harm
Pathogen:
- biological agent that causes disease or illness
Host:
- organism that harbours a parastic, mutualistic or commensalist guest
Vector:
- organism that spread infection by spreading pathogens from one host to another
What is phylogeny
- the study of relationships among different groups of organisms and their evolutionary development
What are cladisitics?
- where organisms are categorised in groups based on the most common ancestor
How can you tell the relatedness of two organisms through amino acids?
- you can compare the DNA sequences between the two organisms by looking for the similarities between bases
How do molecular clocks work
- the number of nucleotide substitutions in related genes is proprotional to the time since they last shared a common ancestor
- as species diverge, there will be a difference in the amino acid sequence due to accumulation of mutations
What is a phylogenetic tree?
- they represent evolutionary relationships among organisms
Define the term clade:
- a group of organisms that consists of a common ancestor and all its lineal discendants
what are the three common assumptions of cladistics?
- Any group of organisms are related by descenet from a common ancestor
- There is a branching pattern of lineage-splitting
- Change in physical characteristics occurs in lineages over time
Why is there a need for multiple definitions of species?
Multiple definitions are required because some specific defitions cannot be applied to organisms that do not reproduce sexually.
- morphological
- biological
- ecological
- genetic
- phylogenetic
What are the definitions of morphological and biological species
Morphological:
- differentiate species through differences in form and structure of organisms
Biological:
- a group of similar organisms that are capable of sexually interbreeding to produce fertile offspring
What defintions of ecological and ecological niches
Ecological:
- defines a species by the resources that the particular group of organsims uses and depends on the specialised ecological niche the group occupies
Niche:
- the role the species plays in an environment
- includes habitat, food, location of reprouction and relationships with other species
What are the definitions of genetic and phylogenetic species
Genetic:
- utilises both inherited genetic traits of an organism plus the amount of genetic variation in a population
Phylogenetic:
- an introducible group whose members are descended from a common ancestor
- all possess a combination of certain defining or deriving traits
