4.3 Flashcards
whats classification
the process of sorting living things into groups- helps us understand species biology and identify new species easier
what does the system of classification consist of
- domain
- kingdom
- phylum
- class
- order
- family
- genus
- species
whats domain
the highest taxonomic rank which contains 3 groups- the eukaryote, archaea and bacteria
whats kingdom
there are 4 eukaryote kingdoms: animalia, plantae, fungi and protoctista and another kingdom, the single celled prokaryota (prokaryotes)
whats phylum
all organisms are sorted based on their basic body design; e.g whether they have a backbone
whats class
organisms are grouped based on general traits; e.g. number of limbs
whats order
a further division based on more specific information e.gg; wolves and cows in the mammalian class (simmilar physiology)
whats family
a group of closely related genera e.g; dogs and cats are divided at the family level
whats genus
a group of closely related species; e.g the hominid genus containing homo erectus and homo sapiens
whats species
the basic unit of classification in this system in which all members show little variation (lions and tigers are diff species)
what does binomial naming use
the binomial naming system uses the genus name and species name to avoid confusion when naming species
how do u use the binominal naming system irl
write the genus and then the species- if writing using paper underline each word but if typing, use italics
why are humans homo sapiens or h. sapiens
because we are the species sapiens or the genus homo
when a new species is identified, how is it named
given a scientific name (based on classification) and a common name
what are artificial classifications used to group
to group things into convenient groups (e.g all yellow flowers grouped)
what are artificial classifications based on
based on few characteristics, do not reflect any evolutionary relationships and provide limited info about species
what is the modern classification system based on
based on natural classification of species which uses multiple characteristics and reflects evolutionary relationships
whats phylogeny
the study of evolutionary relationships between organisms
what are phylogenetic relationships between organisms best depicted with
a phylogenetic tree
what do branch tips on the phylogenetic tree represent
represent species at the end of their specific lineage
what do branching points on the phylogenetic tree represent
represent common ancestors
what do branches on the phylogenetic tree represent
represent evolutionary change/ relatedness
what does the direction phylogenetic tree growing represent
corresponds to the time passing
why do we classify organisms
- study similar species
- easy to identify life if we classify
- each species has different economic benefits- economic benefit and pure science knowledge
- universal naming allows for better communication
- to study evolutionary relationships> better protection of biodiversity
what does the 3 domain system consist of
- eukaryota: contains all the eukaryotes (plants, animals, fungi and different kingdoms of protists)
- bacteria: prokaryotes
- archea: prokaryotes with distinctive metabolisms (extremophiles)
why do we have the 3 domain system
to better represent the fundamental cell biology + evolutionary relationships
whats classification
the arrangement of organisms into groups of various sizes on the basis of shared features
whats taxonomy
a form of classification that focuses on physical similarities between different species, for ease of naming and identification
whats convergent evolution
the development of similar features and adaptations through different evoloutionary pathways
how is use of biological molecules important in classification
-organisms will have same biological molecules
-cytochrome C is a protein used in respiration, all respiring organisms have cytochrome C.
-but its different in different species
-comparisons abt these differences tell us how closely related we are to other organisms
(slight changes in primary structure)
how is use of DNA important in classification
- DNA changes are caused by mutations , these are random and increase with time
- the more changes in DNA, the more mutations have occurred, which means time has passed.
- and more evolution would have taken place, suggesting greater distance in relationship
where does mitochondria DNA come from
the mother
explain how organisms undergo evolution (6)
1- mutations of DNA sequences produce genetic changes, these cause alternate forms of genes ( alleles) to be produced.
2- this creates genetic diversity between individuals of the same species ( intraspecific variation)
3- resources can be scarce, and there can be selection factors such as predators and disease. Individuals compete for survival.
4- individuals with the characteristics most suited to their environment survive for longer, thus have a greater opportunity to reproduce
5-thus they can pass on their genes for advantageous characteristics
6- the next generation will have more individuals with these characteristics, over time, population can permanently change
