4.2.2 Classification And Evolution Flashcards
Define Classification
process of sorting living organisms into groups based on their similarities and differences
Define taxonomy
the study of classification
Define taxonomic group
th hierarchical groups of classification
Define Phylogenetic
the evolutionary relationship between organisms
What are the 7 taxonomic groups, in order? (the first widely used system)
Kingdom, Phylum , Class, Order, Family, Genus, Species
What is the mnemonic to remember the first classification system used
Katy Perry Came Over For Great Soda
What is the taxonomic level that has been added above kindgdom?
Domain
What are 3 reasons why scientists classify organisms?
- To identify species
- To predict characteristics
- To find evolutionary links
Define Species
- The smallest most specific taxonomic group
- contains one type of organism which is able to produce fertile offspring
Explain why horses and donkeys are separate species
- horse and donkeys breed they produce a mule - which is infertile
- mules are infertile bc they have an odd number of chromosomes - meiosis and gamete production doesnt take place correctly bc all chromosomes have to pair up
- can’t be same species as species must produce fertile offspring
Why are mules not given a scientific name and are not a separate species?
- not a seperate species as they are incapable of producing fertile offspring bc odd number of chromosomes
Define scientific name
the name given to organisms consisting of 2 parts
Define binomial nomenclature
SYSTEM of scientific naming of a species made from latin names
- 2 parts - 1st genus - 2nd species
What does the binomial naming system use to make names?
genus and then species
Define generic name
the first word of the scientific name
- the genus
Define specific name
the second word of the scientific name
- the species
How do you write the scientific name of species?
typed?
handwritten?
typed - italics,
handwritten - underlined
- first letter of genus capital
What is the value of the binomial nomenclature system to the scientific community?
- binomial is universal names
- common names vary from place to place
- no 2 species share the same name
- provides information about relationships between species
What are the 5 kingdoms?
give examples of which organisms each contains.
- Prokaryotae - (bacteria)
- Protoctista - (unicellular eukaryotes)
- Fungi - (yeasts,mould,mushrooms)
- Plantae
- Animalia
What are the 5 kingdoms?
give examples of which organisms each contains.
- Prokaryotae - (bacteria)
- Protoctista - (unicellular eukaryotes)
- Fungi - (yeasts,mould,mushrooms)
- Plantae
- Animalia
What are the characteristics of Prokaryotae kingdom?
- unicellular
- no nucleus or membrane bound organelles
- nutrition absorbed through wall/produced internally
- small ribosomes 70s
- cell wall - (murein)
What are the characteristics of Protoctista kingdom?
- mainly unicellular
- sometimes cell wall
- eukaryotic
- nucleus and membrane bound organelles
- nutrition - photosynthesis/ingestion
- some have chloroplasts
What are the characteristics of Fungi kingdom?
- unicellular/multicellular
- nucleus and membrane bound organelles
- cell wall (chitin)
- nutrition absorbed - feed on decay (saprophytic)
- no photosynthesis (no chloroplasts)
- most store food as glycogen
What are the characterstics of Plantae kingdom?
- multicellular
- nucleus and membrane bound organelles
- all have chlorophyll
- nutrients via photosynthesis (autotrophic)
- store food as starch
What are the characteristics of the Animalia kingdom?
- multicellular
- nucleus and membrane bound organelles
- no choloroplasts
- nutrients by ingestion (heterotrophic)
- food stored as glycogen
Why is protoctista described as a dumping ground for species?
- because any eukaryotic organism that doesnt fit into fungi, plantae or animalia is classed as protoctista
What are the 3 domains of life? and the 6 kingdoms that this system uses?
- eukarya
- archaea
- bacteria
* within bacteria the kindgom is: eubacteria
* within archaea the kingdom is :archae-bacteria
* within eukarya the kingdoms: are plantae,fungi, animalia
What are the characteristics of the domain eukarya?
- eukaryotic
- 80s ribosomes
- ceullose/chitin cell wall if present
- RNA polymerase (has 12 proteins)
What are the characteristics of the domain archaea
- prokaryotic
- 70s ribosomes
- RNA polymerase (has 8-10 proteins)
What are the characteristics of the domain bacteria?
- prokaryotic
- 70s ribosomes
- RNA polymerase (has 5 proteins)
- peptidoglycan cell wall
What is the evidence used to create the three domain system?
- rRNA analysis
- sequences of nucelotides in ribosomal RNA (archaea and eukarya closely linked, bacteria separate)
- cells membrane lipid structure
- sensitivity to antibiotics
- molecules in cell wall
How are new explanations of phenomena (facts in question) are scrutinised by scientific community and could end up replacing earlier explanations?
- write sceintific paper describing methods, data, hypothesis, conclusions
- sumbit paper to scientific journal
- paper is read by other scientists before it is published
- paper critically evaluated by scientific community
- lectures, conferences, publish on internet
What occurs in the peer review process?
- check plagiarism
- check data is acceptable and reliable
- check conclusions are logical and valid
- other sceintists try repeat experiments and test theories
Define phylogeny
the evolutionary relationships between organisms
What is a phylogenetic/evolutionary tree?
shows the different species that have evolved from a common ancestor
How do you interpret a phylogenetic tree?
- base of tree = earliest species
- tips of branches = most recent species
What is the advantage of using phylogenetic trees as a form of classification and not taxonomic groupings?
- you can see evolutionary relationships and ancestors of species more clearly
What are 3 different sources of evidence for evolution?
- Palaeontology - (fossils)
- Comparative anatomy - (organisms anatomy diff+similarities)
- Comparative biochemistry - (organisms chemical makeup diff+similarities)
How can the relative age of fossils be determined?
using the different layers (strata) in roks and comparing them
How do fossils provide evidence for evolution?
fossils within layers are different
- evidence of change over time
How does comparative **anatomy ** provide evidence for evolution
comparative anatomy:
- shows divergent evolution from homologous structures
Define homologous structure and divergent evolution
(comparative anatomy)
- homologous structure: a structure that appears superficially (outside) different (and may have different functions) in different organisms but has the same underlying structure
(homologous structures provide evidence for divergent evolution) - divergent evolution: species diverge overtime into 2 different species, results in a new species becoming less like the og one
What is comparative biochemistry?
the study of similarities and differences in the proteins and molecules that control life processes
How does comparative biochemistry provide evidence for evolution?
- small changes in sequences of nucleotides in DNA/Aminoacids in proteins help identify evolutionary links
Define variation
the differences in characteristics between organisms
Define interspecific variation
variation between members of different species
Define intraspecific variation
variation between members of the same species
What are the 2 causes of variation
- genetic variation - caused by differences in genes inherited from parents
- environmental variation - caused by different conditions in the environment
What are 5 causes of genetic variation between individuals within a population?
- alleles - (different versions of a gene that in different combinations code for different characteristics)
- mutations - (changes to the DNA sequence which changes the proteins produced)
- meiosis - (independant assortment and crossing over)
- sexual reproduction - (inheriting a combination of alleles from each parent so individual produced differs from parent)
- chance - (each gamete unique and chance as to which ovum fuses with which sperm)
What are
- 3 charaterstics that are solely genetically determined?
- 3 that are solely environmentally determined?
- 3 that are a combination of genetics and the environment?
- blood group, eye colour, tongue rolling
- scars, piercings, dyed hair
- height, weight, skin colour
How can twin studies help identify the relative influence of genetics and the environment on characteristics?
- identical twins - have same genetics so all variation would be due to environment
- non - identical twins - raised in similar environemnts so variation largely due to genetics
Define continuous variation
- a characteristic that can take any value within a range
e.g. height, mass
Define discontinuous variation
- a characteristic that can only result in certain values
e.g. sex, blood groups
What are the causes of variation that result in discontinuous variation?
- genetic
e.g. bloof type normally by single gene
Define polygenic and multifactorial
- polygenic: controlled by multiple different genes
- multifactorial: involving or dependant on many factors
What are the causes of variation that result in continuous variation?
- tends to be environmental or a combination of many environmental and genetic factors
What are 4 characteristics of a normal distribution curve/graph?
- mean/mode/median are the same
- distribution has bell shape
- 50% of values are less than the mean and 50% greater
- most values lie close to the mean value
What is standard deviation?
- tells you how spread out the data is
greater the standard deviation…
= the greater the spread of data
What does 9 ± 3 in standard deviation mean?
- the mean is 9
- the standard deviation is 3
- so most values are spread out between 6 and 12
What are the meanings of the symbols in the standard deviation equation?
∑= sum of
x = value measures
x with line ontop = mean
n = total number of values in sample
Define adaptation
characteristics that increase an organisms chance of survival and reproduction in its environment
What are the 3 types of adaptation?
- anatomical adaptations
- behavioural adaptations
- physiological adaptations
Define anatomical adaptation
(give 4 examples)
physical features (internal and external)
* body covering (scales/hair/shell/feathers)
* camouflage
* teeth (shape and type)
* mimicry (copying other animals appearance/sounds
* curled/rolled leaves minimise water loss
Define behavioural adaptations
(give 4 examples)
the way an organism acts
(inherited or learnt)
* survival behaviours (playing dead)
* courtship dances
* seasonal behaviours (migration+hibernation)
Define physiological adaptations
(give 4 examples)
metablolic/processes that take place inside an organism
* poison production
* antibiotic production (response to infection)
* water holding (in body)
Define analogous structures
Define convergent evolution
- analogous structures: structures that have adapted to perform the same functions but have different genetic/evolutionary origins
- convergent evolution: when unrelated species share similar features that perform the same function but have different genetic/evolutionary origin
Why might organisms from different taxonomic groups show similar features?
- same/similar niche or lifestyle so same needs
What are 4 examples of convergent evolution
- placental mole and marsupial mole
- marsupial and placental mouse
- flying squirrel and flying phalangers
- wolf and tasmanian wolf
Compare the features of the marsupial mole and placental mole
placental mole:
- burrows through soft dark soil
- dark brown for camouflage
marsupial mole:
- burrows through soft sandy soil
- pale yellow for camouflage
both:
- eat worms and grubs
- streamlined body shape
- forelimbs adapted for digging
- velvety fur for smooth movement through soil
How can convergent evolution make true evolutionary relationship discovery difficult?
how can this be overcome?
- usually, more similarities mean more closely related so more common recent ancestor
- through convergent evolution similarities arise bc of similar habits and selection pressures not common ancestors
- overcome: look at genetics/characteristics that are selectively neutral e.g. (DNA sections without function)
Define evolution
the change in allele freuquency within a gene pool overtime
Define natural selection
the process by which an allele that provides a selective advantage becomes more common in a population over time
Define allele frequency
the proportion of the copies of a gene in a gene pool that are of a particular type
Define gene pool
all the alleles of all the genes in a population
Define selection pressure
- factors that affect the organisms chances of survival/reproductive success
Define selectively neutral allele
- a variety of a gene that doesn’t provide a selective advantage or disadvantage to the organism
Define advantageous allele
- a variety of a gene that provides a selective advantage to the organism
Define advantageous characteristic
- one form of a part of an organisms phenotype that provides it with a selective advantage
What are the steps in the process of adaptations evolving by natural selection?
- individuals within a population show variation in their phenotypes
- selection pressures (environmental factors e.g. disease/competition/predation) create struggle for survival
- individuals with better adaptations more likely to survive and have reproductive success - can reproduce and pass of advantageous adaptations to offspring
- overtime proportion of population with advantageous adaptations increases
- over generations this = evolution as favourable adaptations become more common in the population
How has natural selection resulted in change in frequency of dark and pale moths in populations of peppered moth near industrial towns and cities overtime?
- selection pressure is being eaten by birds
- before industrial revolution more light moths
- during industrial revolution trees got darker from pollution
- dark coloured moths can camouflage and better adapted to this environment so can reproduce and pass alleles for dark colouring to offspring
- dark moths increase and alleles for dark colour more common in population
- since clear air act reduced pollution levels, bark lighter coloured so pale allele in moth gene pool increased
What are the characteristics that are likely to allow a population to evolve to tolerate a change in environment and the characteristics that are likely to cause a population to go extinct due to a change in environment?
????
- evolve to tolerate change - larger population size = more genetic variation in population
- higher reproduction rate
- ## ability to pass plasmids from 1 individuals to another
How has human activity resulted in evolution in populations of the bacterium Staphylococcus aureus, the Sheep blowfly Lucilia cuprina, and the bacterium Flavobacterium.
staphylococcus aureous:
Change in environment in use of antibiotic
Eventually species is resistant
Sheep blowfly:
Change in environment is introduction of pesticide
Eventually species resistant
Flavobacterium:
Change in environment is nylon present in waste water from factories
The selection pressure is this nylon which is a new protein source
Eventually species adapted to novel food source as all individuals produce nylonase
