4.2.2 Classification and Evolution Flashcards
what is classification
the process by which living organisms are sorted into groups based on similarities and differences between species
what is taxonomy
the study and practice of naming and classifying species and groups of species within the hierarchal classification scheme
what are the taxonomic groups
kingdom, phylum, class, order, family, genus, species
describe the kingdom in size
the biggest and broadest taxonomic group
describe species in size
the smallest and most specific classification
what is the hierarchal classification also known as
linnaean classification
who was carl linnaeus
the first person to propose the classification system
what is the most recent classification added
domain
where is domain placed in the taxonomic group order
at the top
why do scientists classify organisms
- to identify species
- to predict charactersistics
- find evolutionary links
what are the three domains
- archea
- bacteria
-eukarya
what is the definition of a species
a group of organisms that are able to reproduce to produce fertile offspring
give an example of a species
donkeys can reproduce with other donkeys, but when a horse breeds with a donkey the offspring produced is infertile
why is a horse and donkey bred make the offspring infertile
because their cells contain an odd number of chromosomes
so meiosis and gamete production cannot take place correctly
why is the system of giving names due to a charcterstic not a sufficient method?
- same organisms may have a complete different common name in different parts of one country
- different common names are used in different countries
- translation of languages/dialect may give different names
- same common name could be used for a different species in another part of the world
what is the binomial nomenclature
a system created by carl linnaeus to give animals names to ensure aniamls of the world are discussing the same organism
describe the naming steps of the binomal menclature system
- first word indicates the organisms genus (generic name , like a surname)
- second word is the organisms species (specific name)
-no two species have the same generic and specific name
how would you represent an organisms scientific name
printed - italics
handwritten - underlined
capital letter for beginning of genus name
give an example of an organisms scientific name
Canis familiaris (dog)
what are the 5 kingdoms
prokaryote, protoctista, fungi, plantae, animalia
what did early classification rely on?
observable features only to place organisms into groups such as appearance and anatomy
what did Aristole classed all things as
plants and animals (live and move in water, live and move on land, move through air)
what lead to the 5 kingdom system
when microscopes developed overtime and more organisms could be studied in detail
what is a prokaryote general features
- unicelluar
- no nucleus or membrane - bound organelles
- no visible feeding mechanism, nutrients are absorbed through the cell wall or produced internally
what are the general features of protoctista
- mainly unicellular
- has a nucleus and other membrane-bound organelles
- some have chloroplasts
- some sessile, but others move by cillia, flagella, or amoeboid mechanisms
- nutrients are aquired by photosynthesis (autotrophic and heterotrophic feeders)
what are the general features of fungi
- unicellular or multicellular
- a nucleus and other membrane-bound organelles and a cell wall which is composed chitin
- no chloroplasts or chlorophyll
- no mechanisms for locomotion
- most have a body for mycelium made of threads or hyphae
- nutrients are aquired by absorption - mainly from decaying material, also saprophytic feeders, some are parasitic
what are the general features of plantae
- multicellular
- a nucleus and other membrane-bound organelles including chloroplasts and a cell wall mainly composed of cellulose
- all contain chlorophyll
- autotrophic
what are the general features of animalia
- multicellular
- a nucleus and membrane-bound organelles
heterotrophic
who created the three domain system
carl woese in 1990
why did he create the three domain system
as scientists started to discover more about biology and biochemistry, which led to discovery that there were some majot differences within the prokaryote kingdom
what are the three domains?
bacteria, archaea, eukarya
describe eukarya
they have 80s ribosomes - RNA polymerase contains 12 proteins and includes the kingdoms: protists, fungi, plantae, animalia
describe archaea
they have 70s ribosomes - RNA polymerase of different organisms contains between 8 and 10 proteins and is very similar to eukaryotic ribosome
describe bacteria
they have 70s ribosomes - RNA polymerase contains 5 proteins
what are the two kingdoms that prokaryotes are divided into
archaeabacteria and eubacteria
describe archaeabacteria
(ancient bacteria) can live in extreme environments, example: methanogens live in anaerobic environments such as sewage treatment plants and make methane
describe eubacteria
(true bacteria) found in all environments, and most common bacteria
what is phylogeny
the study of evolutionary relationships between organisms
what are the advantages of phylogeny
- it can be without referring to the Linnean classification
- it produces continuous tree whereas classification requires discrete taxonomical groups
- it is not as misleading as the hierarchal classification of the linnean system
what does biological species concept
the ability of two individuals to successfully produce viable fertile offspring
what is morphological species concept
whether individuals look similar
what is phylogenetic species concept
how closely related individuals are evolutionarily
what is ecological species concept
whether the individual use or can use the same set of biological resources
what is phylogenetic species concept
concept of a species as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining or derived traits
what is a phylogenetic tree
a diagram used to represent the evolutionary relationships between organisms, they are branched diagrams
who made the natural selection theory
charles darwin
where was darwin’s ideas developed
around the world including the galapagos islands
what was the 4 observations darwin made
- offspring generally appear similar to their parents
- no 2 individuals were identical
- organisms have the ability to produce large numbers of offspring
- population in nature tend to remain fairly stable in size
how did wallace contribute to darwin’s ideas
- some organisms had advantageous adpatations evolved by natural selection
- geographical boundaries often marked species boundaries
-most of the individuals found in a habitat were the best fitted for that environment
what are the evidence for evolution
fossil evidence
comparative anatomy
comparative biochemistry
what is a fossil
mineralised or preserved remains of an animal, plant or microorganismh
how are fossils made
animal/plants -> organisms becomes buried under sediments -> high temp and pressure turns sediment into stone -> the remains dissolve and leave behind a space
-> minerals crystallise in the space and forms a cast
are complex organisms found in recent rock layers or old
recent
how can scientists show how closely related organisms have evolved from same ancestor
by studying similarities in the anatomy of fossil organisms
what is the homologous structure
a structure that appears superficially different in different organisms but has the same underlying structure
describe comparative anatomy
bones that are used for very different functions but have the same structure, which suggest they have all evolved from the same common ancestoras the vertebrate limbs have all evolved from the structureh
what does comparative anatomy provide evidence for
divergent evolution and would most likely be due to migration or loss of habitat
what is comparartive biochemistry
the study of similarities and differences in the proteins and other molecules that control life processes
describe comparative biochemistry
some important molecules are highly conserved among species
how to discover how closely two species are related
- there are many possible different types of amino acids, but only 20 are used to make proteins
- the molecule of inhertance in all cellular organisms is DNA
- the genetic code that specifies an organisms amino acids is basically the same in all organisms
- ATP is the universal currency for energy in all cells of all organisms
molecular evidence
- difference in the sequence of a DNA molecule would be due to mutations as the genetic code is universal and so a particular sequence of DNA codes for the same ssequence of amino acids in both an animal, palnt or bacterium
- the more similar the sequence in parts of the DNA, more closely related the species
- more differences in sequence in part of the DNA then the earlier the evolution of the two species and so less closely related they are
what is variation
the difference between species and the differences within species
what is intraspecific variation
variation between members of the same species
(used to study natural selection and evolution)
what is interspecific variation
differences between species (identify different species and to classify them
what is continuous variation
variation in a feature that shows a range of phenotypes between two extremes with many intermediates
what causes variation
an organisms genetic
the environment in which the organism lives - this causes environmental variation
what is discontinuous variation
variation in a feature that has discrete categories without any intermediates
how does allele affect variation
genes have different versions (alleles) and the individuals in a species population may inherit different alleles of a geneo
how does mutatuions affect variation
changes to DNA sequence and therefore genes can lead to changes in the protein coded for and this can affect the physical and metabolic charactersitics
how does meiosis affect variation
formation of gametes and the process of independent assortment and crossing over to mix up the genetic material
what are the other two factors that affect variaiton
sexual reproduction and chance - random fertilisation as a result of which gametes combine
what are combined effects of variation
- not all genes are active at the same time, for example, puberty.
- changes in the environment can also directly affect which genes are active (melanin production)
what is the null hypothesis
the hypothesis that states there is no difference between x and y
- null hypothesis is the default, we are pessimistic and assume that there is no relationship, it is the job of your experiment to prove it wrong
- normal hypothesis is called the alternative hypothesis
what is the degree of freedom
the number of values that could vary, its usually the number of results -1
what is standard deviation
a measure of the spread of data around a mean
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