module 4 bio classification and evolution

arranges species into groups according to their evolutionary origins and relationships

it tells us how closely related species are and how recent their shared common ancestors are

Domain

Kingdom King

Phylus Phillip

Class Comes

Order Over

Family For

Genus Gay

Species Sex

each group is called a taxa

because there is smaller groups arranged within large groups adn there is no overlap between groups

that means that memebrs of different species can fit into the same genus but there is no overlap between those different species

used universally so that data on different species can be used

each species is universally identifed with two names first name is genus (capitalsied ) and the second name is species (lower case) e.g. Homo sapiens

common names can be misleading as they dioffer from langauge to language

common names are usually basde on physical appearance whereas the binomial system gives you an indication of how closely related different species are - different species same genus they must be closely related

prokaryotae

protoctista

fungi

plantae

animalia

unicellular

no membrane bound organelles

small ribosomes

a ring of DNA (plasmid) with no associated proteins

it has no feeding system it instead absorbs nutrients across its surface or some photosyntheise

unjcellulare

has a nucleus and membrane bound organelles

somr have chloroplasta and some have cilia or flagella for movememnt

nutrients are absorbed either by photosynthesis ingestion of other organisms or some are parasites

can be unicellular of multicellular

have a nucleus and membrane bound organelles

no chlororplasts

cannot move ]have a body made of threads of hyphae

nutrients are absorbed from dead or decaying matter (they are saprobionts)

food can be stored as glycogen

multicellular

have a nucleus and membrane bound organelles

have chloroplasts and dont move

nutrients are absorbed by photodynthesis and food is stored as starch

mulitcellular

have a nucleus and membrane bound organelles

no chloroplasts

they can move using cilia flagella or muscles

nutrienst are obtained by ingestion and food can be stored as glycogen

used to be based on observable characteristoics which can be very misleading as individuals of the same species in different habitats can look very differnet

indviduals of different soecies ca also look very similar if they live in the same habitat and are exposed to very similar envirnmental conditions

the accuracy f classification improved as advances in immunology and genome sequencing advanced

DNA base sequences for common genes can now be compared as a measure of how closely related the organisms are

the more clsoely relsted the species the higher the degree of similarity in the base sequences

this is because mutations accumulate over time and thhose species must have evolved from common ancestors longer ago and hav etherefore had more time to accumulate mutations resulting in morre different base sequences

the sequence of amino acids in a polypeptide chain can also be compared because this is determined by the sequence of DNA bases

however

method wont be as accurate as DNA bases because the genetic code is degenerate meaning soem of thsoe amino acids may have been coded for by different codon s

1977 Carl Woese

Eukaryota, Archea and bacteria

organisms are split into these three domaisn based on the type opf r RNA and ribosomes they have and the cell mebrane structures

under tghus system there are 6 kingdoms as prokaryotae is split into eubacteria (true bacteria) and archaebacteria

the split of prokaryotae under carl woese’s system

found everywhere and most bacteria are in this system

split of prokaryotae iunder carl woese’s system live in extreme envirnments such as thermal hot springs and anaerobic environments

natural selection is the process that leads to evolution

it is the change in allele frequency over many generations in a populatioon

fossil record provides evidence of howe species have changed over time and how species have evolved fossils are the imprints or remain sof dead plants or animals in rocks

By comparing DNA base sequences of common genes we can see how closely related species are this ahs enabled scientists to estimate the point in history when two species shared a common ancestor cytochrome C is a protein found in mitochondria which a large number of species have it is often the protein or gene which is compared

a species that is better adpated to its environment

species becoming better adapted to their environment adaptations may be anatomical physiological or behavioural

1. new alleles for a gene are created by random mutation

2. if the new allele increases the chances of the individual to survive in that environment then they are more likely to survive and reproduce

3. this reporduction passes the advantageous allele onto the next generation

4. as a result over many generations the new allele increases in frequency in the population

anatomical physiological or behavioural

adaptations that are internal or external physical features

animals from different taxonomic group may have similar anatomical adaptations this si due to convergent evolution when different species are expsoed to similar selection pressures they will undrgo natural selection for similar alleles and therfore become more genetically similar

adaptations that are changes in the way the organism acts these can be genetic in cause or learnt fro parents

adaptations that are processes that atke place within an organism

interspecific and intraspecific

variation between members of different species

variation between members of the same species

genetic variation eithin the samr especies is introduced through mutations crossing over and independent assortment in mitosis sexual reproduction adn random fertilisation

environmental factors can also cause variation

continuous or discontinuous

refers to traist thqt are controled by genes and the environemnt

represented graphically as a histogram

e.g height weight etc

refers ti traits that are controlled by a single gene and the environment has no impact thereofre individuals can fit into categories and this is represented as a bar chart

e.g. eye colour and blood group