Chapter 10 - Classification and Evolution Flashcards
Define taxonomy
the study of the principles of classification of organisms according to their observable features or genetic characteristics
what are the taxonomic groups
Kingdom, phylum, class, order, family, genus, species
how to describe the taxonomic groups
heirarchical
What system of classification has been recently added, where does it fall
The domain system, above kingdom (at the top of the hierarchy)
Reasons for classification
- identification of a species
- prediction of characteristics
- identification of evolutionary links
what is the purpose of having a universal system of classification
- understood worldwide by scientists so they can share their research and see links between different organisms even on different continents
What are the 3 domains
archaea, bacteria and eukarya
define species
a group of individual organisms whose members are able to interbreed freely to produce fertile, viable offspring
define classification
The process by which living organisms are sorted into groups, organisms in the same group share similar features
why are hyrbrids infertile
- different numbers of chromosomes so they cannot pair to form bivalents
- crossing over of DNA cant occur
features of Eukarya
- membrane bound organelles
- nucleus
features of archaea
- live in harsh environments
- phospholipid monolayer
- circular dna
- no nucleus or membrane bound organelles
features of bacteria
- peptidoglycan cell wall
- circular dna
- no nucleus or membrane bound organelles
who and why made domain system
carl woese noticed the rRNA of prokaryotes had differences
- differences in protein synthesis
why use binomial nomenclature
- globally recognized to avoid confusion
- show close relation
- easy sorting
- every single species has a unique name
what does binomial nomenclature show
genus (capital)
species (lowercase)
how to write binomial nomenclature (typed/written)
typed: italics
written: underlined
what are the 5 kingdoms
- Animalia
- Plantae
- Fungi
- Protoctista
- Prokaryotae
what are the levels of classification
molecular, embryological, anatomical and behavioural
ribosomes/ protein synthesis of eukarya
80S
rna polymerase has 12 proteins
ribosomes/ protein synthesis of archaea
70S
rna polymerase has 8-10 proteins
ribosomes/ protein synthesis of bacteria
70S
rna polymerase has 5 proteins
define phylogeny
the study of how closely related different species are (evolutionary relationships)
define phylogenetic classification
- differentiating organisms on genetics
- more similar dna or amino acid sequence = more closely related
what validates scientific research
- conferences
- reproduceable
- repeatable
- experimental research
advantages of phylogeny
- produces continuous tree
- not put in specific groups they may not fit
define evolution
the gradual change in heritable traits of organisms over successive generations)
what 4 observations did Darwin make
- organisms produce more offspring than can survive
- variation in characteristics of the same species
- characteristic passes on
- best adapted individuals survive
principles of natural selection
- overproduction of species leads to competition
- variation due to mutation
- selection by adaptation
- breed and pass on characteristics
how is palaeontology evidence for evolution
- fossils of simplest organisms found in oldest rocks
- dating sediment
- oldest rock further down
- there are gaps in fossil record
how is comparative anatomy evidence for evolution
- homologous structures eg. pentadactyl limbs
- evidence of convergent evolution
how is comparative biochemistry evidence for evolution
- similarities dna base sequence
- similarities amino acid sequences
- study rRNA and cytochrome c
define interspecific variation
variation between members of different species
examples of interspecific variation
number of legs of species
define intraspecific variation
variation between organisms within a species
examples of intraspecific variation
humans: height, eye colour
define genetic variation
differences in genetic material an organism inherits from its parents
define environmental variation
variation due to the environment an organism lives in
causes of genetic variation
- alleles
- mutation
- meiosis (crossing over)
causes of environmental variation
for plants: sunlight, climate (they’re less mobile)
examples of variation that is both environmental and genetic
- height: genetic and due to diet and health
Define continuous variation
A characteristic that can hold any value in a given range
What shape does continuous variation usually take
Normal distribution- bell curve
Define discontinuous variation
A characteristic that can only result in certain values
define anatomical adaptation
physical features (internal and external)
examples of anatomical adaptations
- body coverings (hair, scales)
- camouflage
- teeth/ jaw
- mimicking another animals sound/ appearance
define behavioural adaptations
how an organism acts - can be inherited/ learnt from parents
examples of behavioural adaptations
- survival behaviours (acting dead etc.)
- attracting a mate
- seasonal behaviour (migration/ hibernation)
2 categories of behavioural adaptations
innate and learnt
define innate behaviour
ability due to inherited from genes eg. spiders and webs
define learned behaviour
adaptations learnt from experience/ observing others eg. using tools
define physiological adaptation
processes that occur within an organism
examples of physiological adaptations
- producing poison
- producing antibiotics
- water storage
define homologous structure
similar anatomical structure, but not superficial structure
define analogous structure
similar superficial structure that performs similar roles, but different anatomical structures
why do homologous structures arise
due to divergent evolution
why do analogous structures arise
due to convergent evolution
example of convergent evolution
placental and marsupial mole
define the founder effect
the loss of genetic variation that occurs when a new population is established by a very small subset of individuals from a larger population
how does founder population differ to original population
- reduced variation
- fewer genotypes and phenotypes
