evolution and classification

What is classification?

the process by which animals are sorted into groups

why is classification useful?

• identifies species

• predicts characteristics

• finds evolutionary links - species in the same group share a common ancestor

• a single classification system allows scientists to share research worldwide

what is the order of taxonomic rank?

domain

kingdom

phylum

class

order

family

genus

species

what are the three domains?

archaea

eubacteria

eukaryote

what are the five kingdoms?

plantae

animalia

fungi

protoctista

prokaryotae

how does the phylum group organisms?

wether they have a backbone or not

how does class group organisms?

by similar general traits

how does the order group organisms?

according to the organism nature

e.g. herbivore

how does the family group organisms?

through similar genera based on reproductive characteristics

what is the genus?

a group of similar species

what is the definition of species?

group of organisms that can interbreed to give off fertile offspring

what is taxonomy?

branch of science studying classification

what is binomial nomenclature?

scientific naming of a species with a two part latin name

advantages of binomial system :

• organism may have local names but will have only one binomial name therefore universal worldwide

features of the animalia kingdom :

• eukaryotic

• no cell wall

• multicellular

• a nucleus and other membrane bound organelles

• heterotrophic

• glucose stored as glycogen

what does heterotrophic mean?

large molecules digested into smaller ones for absorption

-eats other organisms

features of the plantae kingdom :

• eukaryotic

• multicellular

• cellulose cell wall

• autotrophic

• store glucose as starch

examples of plantae kingdom :

• algae

• fungi

• conifers

features of the fungi kingdom :

• eukaryotic

• chitin cell walls

• usually multicellular or have mycelium (can be unicellular e.g. yeast)

• no chloroplasts

• saprophytic feeders

• store glucose as glycogen

examples of organisms in the fungi kingdom :

• mould

• mushrooms

• yeast

what does saprophytic feeder mean?

feeds on dead or decaying organisms

features of a prokaryotea kingdom :

• prokaryotic

• unicellular

• no nucleus - circular DNA

• absorbs nutrients or produces nutrients via photosynthesis

examples of organism in the prokaryotae kingdom :

• bacteria - e.g. E.coli, Staphyloccus aureus

features of the protoctista kingdom :

• eukaryotic

• single cell organisms

• some have chloroplasts

• moving using cilia, flagellum and amoeboid mechanisms

• autotrophic and heterotrophic

examples of organisms in the protoctista kingdom :

• amoeba

• paramecium

• protozoa

features of the bacteria domain :

• prokaryotic

• circular dna

• 5 proteins in RNA polymerase

• cell wall of peptidoglycan

• 70 ribosomes

features of the domain archaea :

• prokaryotic

• circular DNA

• some have introns

• 8 - 10 proteins in RNA polymerase

• some can grow at 100c

• 70 ribosomes

features of the domain eukarya :

• eukaryotic

• linear DNA

• membrane bound organelles

• introns

• 12 protein in RNA polymerase

• cytoskeleton

• 80 ribosomes

what is phylogeny?

classification according to evolutionary relationships

what does monophyletic mean?

belonging to the same phylogenetic group

what does the fossil record do?

• place events and species in the right geological era

• evidence for how organisms evolved

disadvantages of the fossil record :

• only bony organisms leave fossil remains

• many fossils are unusable due to mining and other rock damage

what is the law of superstition?

that undisturbed rock in the bottom layers is older than the top layers

how does the law of superstition help the fossil record?

fossils can be dated according to the layer of rock they were found in

how does radiocarbon tell us the age of a fossil?

amount of carbon emitted is proportionate to the age of the fossil

how have fossils influenced the theory of evolution?

evidence of how organisms evolved and adapted

• can be shown in a ‘tree of life’ showing all species are related to each other

what is comparative biochemistry?

study of similarities and difference in proteins and other molecules that control life processes

what is the hypothesis for neutral evolution?

• evolutionary changes are caused by genetic drifts

• variation in the structure doesn’t affect function

• proof for Darwin’s theory of evolution

what is cytochrome c?

important enzyme with control over respiratory chain

how is cytochrome c involved in evidence for evolution?

linked to the brain enlargement in primates showing evolutionary traits

how is ribosomal rna evidence for evolution?

can distinguish organisms on the species level and trace evolutionary relationships through variation of the rRNA sequences

how does ribosomal RNA change?

through mutations

what is interspecific variation?

the difference between different species

what is intraspecific variation?

the difference between individuals of the same species

continuous variation :

• quantitative data

• usually shown on a line graph

• controlled by genes and environment (e.g. height, length of leaves)

discontinuous variation :

• qualitative data with distinct categories

• usually shown of bar graph

• affected by your genes (e.g. blood group)

anatomical adaptations :

when the internal and external physical features adapt

• camouflage

• body coverings

• waxy layers to prevent water loss

physiological adaptations :

when a internal body process will adapt to regulate and maintain homeostasis

• poison production

• water holding frog

• antibiotic production

behavioural adaptation :

changes in how the organism acts - can be innate or learned

• hibernation

• nocturnal

• migration

marsupial mammal characteristics :

• short pregnancy

• don’t develop a fully formed placenta

• born early in development and climb to the mothers pouch where they continue to grow

placental mammal characteristics :

• long gestation period

• develop a placenta allowing nutrient and waste in and out of fetus

• born more developed

monotreme characteristics

• lay eggs

• secrete milk

• have one hole for egestion, reproduction and laying eggs

what is convergent evolution?

where distantly related organism develop similar characteristic due to adapting to similar necessities

what is uniformitarianism?

past changes of the earth were result of a continuous and uniform process

what were darwin’s four methods of evidence?

• similarities between ancient remain and modern species

• fossil evidence

• similarities between current living organisms

• similarities between embryos

who also came up with the theory of evolution?

alfred wallace - didn’t have the status or money to become famous like darwin

definition of comparative anatomy?

similarities and differences between organisms anatomy and physiology

what is a homologous structure?

structure that appears different in different organisms but has the same basic format

example of a homologous structure :

pentadactyl limb

• it is different in different species however all share the same five fingered bone structure

• suggests a common ancestor

what are analogous structures?

structures that are similar in unrelated organisms because they have evolved to do the same job

what is divergent evolution?

when different species have evolved differently to their environments but they share a common ancestor

what is selection pressure?

external factors that affect an organisms ability to survive

• e.g. climate, food availability, disease, mate

what is a gene pool?

total number of alleles in a particular population at a specific time

what is a allele?

form of gene

what is a phenotype?

characteristics of an organism

what is the genotype?

genetic composition of the organism (the alleles it possesses)

mnemonic for natural selection by evolution :

very many able clever students biology pass ocr frequently

how to answer evolution by natural selection?

• variation - difference between individuals of the same species

• mutation - random change in DNA

• adaptation

• competition

• survival

• breed

• pass on advantageous alleles

• over many generations

• frequency of advantageous allele increases

example of antibiotic resistant :

• methicillin resistant to many antibiotics

• rapid bacteria reproduction resulting in short time of evolution

• resistant individuals survived

implication of antibiotic resistant for humans :

• have to take full course of antibiotics for it to work

• many bacteria are resistant to common antibiotics

example of pesticide resistance :

• sheep blow flies became resistant to diazinon over 5 years

what is pre-adaptation?

when a pre-existing trait is advantageous in a new situation

definition of species :

organisms that are able to interbreed to produce fertile offspring

definition of population :

number of the same species that live in the same habit at the same time

definition of habitat :

the natural home / environment and organism lives in

definition of ecosystem :

where the organism interact with the non living condition in an area

what are abiotic factors?

the non living chemical and physical components of an ecosystem