M4 C10: classification and evolution Flashcards
what does the term biological classification mean?
the organisation of living and extinct organisms into groups based on similarities and differences between species
what does the term taxonomy mean?
the study and practice of naming and classifying species and groups within the hierarchical classification scheme
what is the classification system?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
what are the problems with naming organisms based on a particular characteristic?
-same organisms may have completely different name in other parts of the country
-different common names are used in different countries
-same name could be used for different species in different countries
what is the binomial system?
a system of naming species in which each species has 2 names. a generic name and a specific description
what are the 5 kingdoms?
prokaryotes
protists
fungi
plants
animals
what did early classification rely on?
observable factors such as anatomy
what are prokaryotes?
mostly unicellular
no nucleus but has loops of DNA
autotrophic and heterotrophic
no membrane bound organelles
smaller ribosomes
free living or parasitic
what are protists?
single celled
can have plant or animal features
membrane bound organelles
autotrophic and heterotrophic as they can photosynthesise, feed on prey, use extracellular enzymes
are parasites
what are fungi?
eukaryotic
can exist as single cells or have mycelium (network of root like structures)
cell walls made of chitin
cytoplasm is multinucleate
mostly free living an saprophytic (causes decay of organic matter)
what are plants?
eukaryotic
multicellular
contain chlorophyll
autotrophic
what are animals?
eukaryotic
multicellular
heterotrophic
usually mobile (can move)
what are the 3 domains?
eukarya
archaea
bacteria
why were the domains made?
major differences discovered within prokaryotes showing they weren’t that closely related
what is evidence for classification?
1)evidence from bio molecules found in species
2) certain bio molecules are found in all living organisms for essential processes
3) earliest forms of life would have identical versions of these molecules this means any changes are due to evolution
4)comparing dna sequences
5)comparing amino acid sequences
what does the domain eukarya include?
protists
fungi
plants
animals
what is archeae?
can live in extreme environments, these include thermal vents ect.
what is bacteria?
true bacteria, contain peptidoglycan in cell walls
what is artificial classification?
done for convenience and is only based on a few characteristics. it provides limited information and doesn’t reflect evolutionary relationship
what is natural classification?
involves more detail and uses many more characteristics. based on homology and changes in knowledge. reflects evolutionary knowledge
what is homology?
the existence of shared features that are inherited from a common ancestor. shared features may not be used for the same function.
what is phylogeny?
study of evolutionary relationships between organisms and studying how closely different species are related
what are advantages of phylogeny?
-can be done without referring to linnean classification
-provides a continuous tree whereas classification requires discrete taxonomical groups
-not as misleading as hierarchical classification as it shows time
what is the phylogenetic species concept?
how closely related individuals are evolutionary eg common ancestors
what is the biological species concept?
ability of 2 individuals to produce fertile offspring
what is the morphological species concept?
whether organisms look similar
what is the ecological species concept?
whether individual use the same set of biological resources
what did Darwin say about evolution?
proposed ‘natural selection’
offspring are similar to parents
no 2 individuals are the same
populations are mainly stable
can produce multiple offspring
what did wallace say about evolution?
some organisms have advantageous adaptations via natural selection
things habitat is where it is most suited for the environment
map boundaries represent species boundaries
what can we use as evidence for evolution?
fossil evidence
comparative anatomy
comparative biochemistry
How do fossils provide evidence for evolution?
-mineralised remains of a organisms or imprints.
-sequence in which organisms are found matches there links to each other
how does comparative anatomy provide evidence for evolution?
homologous structures which are look different and perform different functions, but has the same underlying structure shows that some organisms have a common ancestor
what is divergent evolution?
when two groups of the same species evolve different traits within those groups in order to accommodate for differing environmental and social pressures, which could result in different species
how does dna provide evidence for evolution?
The differences between the nucleotide sequences in the genes of different species can provide a lot of information:
The more similar the sequence the more closely related the species are
what does biochemistry show about evolution?
molecules, such as amino acid sequences and antibody structure can also be compared for similarities between species. More closely related organisms have share more similarities in their molecules.
what is cytochrome c?
short protein used in respiration
sequence of the amino acids of cytochrome can vary between species the more similar the sequence the more closely related the species are.
what is variation?
differences between and within species
What is intraspecific variation?
variation within species
what is interspecific variation?
variation between species
what is continuous variation?
variation in a feature that has many intermediate values such as leaf length, body mass, height
what is discontinuous variation?
variation in a feature that has discrete categories without any intermediates. eg; blood groups
what are 2 causes of variation?
genetic
environmental
what are some causes of genetic variation?
alleles- different genes
mutations- changes dna sequence
meosis
sexual reproduction
chance of which gametes fertilise
what can cause environmental variation?
climate
food
lifestyle
what is an adaptation?
the way a structure function or aspect of behaviour helps an organisms survive in its environment or perform a activity
what are behavioural adaptations?
way an organism behaves to increase survival. can be inherited or learnt.
can be survival, courtship or seasonal behaviours
what are physiological adaptations?
processes inside a organisms body to help it survive such as poison production, antibiotic production and water holding
what are anatomical adaptions?
structural features of an organism which increases survival such as body covering, camouflage, teeth and mimicry
what are adaptations of marram grass?
anatomical- long roots
behavioural- when covered by sand it grows quicker to reach sunlight
physiological-can roll up due to hinge cells in lower epidermis
what is convergent evolution?
organisms evolve similarities because there adapt to similar environments/ pressures
what is analogous structure?
have adapter to perform the same function but have a different orgin
what is natural selection?
process by which organisms better suited to the environment survive and reproduce passing on there characteristics to their offspring
how does natural selection occur?
mutation creates alternate versions of genes. this creates genetic variation. Selection pressure creates a struggle for survival. individuals with more advantageous genes more likely to survive and these then pass on their genes to the next gene
