4.2.2 Classification and Evolution Flashcards
classification definition
name given to process by which living organisms are sorted into groups
taxonomic groups
7 ordered groups of hierarchy
what are the taxonomic groups
kingdom
phylum
class
order
family
genus
species
smallest and most specific classification group
species
largest and least specific classification group
kingdom
why do scientists classify organisms
to identify species
to predict characteristics
to find evolutionary links
How are organisms classified
separate into the 3 domains
and then classify into individual species - each group contains one type of organism
species
a group of organisms that are able to reproduce to produce fertile offspring
what are the 3 domains
archaea
bacteria
eukarya
what happens to the organisms in each group as you go down the hierarchy
become more similar and share more of the same characteristics
what species are humans
homo sapiens
binomial nomenclature
system used to ensure scientists are discussing the same organism all over the world
what are the different parts of the scientific name of all species
1st word = genus - shared by close relatives
2nd word = species - the specific name
how to write the scientifc name
genus should have capital letter species should be lowercase
what are the 5 kingdoms
prokaryote
Protoctista
fungi
plantae
animalia
general features of prokaryote
unicellular
no nucleus or membrane bound organelles
no visible feeding mechanism - nutrients are absorbed through cell wall or made internally by photosynthesis
- bacteria
general features of Protoctista
mainly unicellular
nucleus and membrane bound organelles
some have chloroplast
some are sessile but others move by cilia, flagella
- unicellular eukaryotes
general features of fungi
uni or multicellular
nucleus and membrane bound organelles
cell wall composed of mainly chitin
no chloroplast or chlorophyll
no mechanism for locomotion
have body or mycelium made of threads or hyphae
nutrients acquired by absorption from decaying material
store food as glycogen
-yeasts moulds and mushrooms
general features of plantae
multicellular
nucleus and membrane bound organelles including chloroplast
cell wall composed of cellulose
contain chlorophyll
dont move
nutrients acquired by photosynthesis
store food as starch
autotrophic feeders
nutrients acquired by photosynthesis
make there own food
saprophytic feeders
nutrients acquired by absorption from decaying material
some are parasitic
general features of animalia
multicellular
nucleus and other membrane bound organelles
no chloroplast or cell wall
move with aid of cilia, flagella or contractile proteins, sometimes in form of muscular organs
nutrients acquired by ingestion
food stored as glycogen
heterotrophic feeders
nutrients acquired by ingestion
how do scientist compare evolutionary relationships between species
compare similarities in their DNA and proteins of the different species
6 kindoms
eubacteria
archaea - bacteria
Protoctista
plantae
fungi
animalia
why is there eubacteria and archaea - bacteria
as they have a different chemical makeup
archaea - bacteria
live in extreme environments such as air vents, anaerobic conditions and highly acidic conditions
eubacteria
found in all environments
phylogeny
evolutionary relationships between organisms
phylogenetics
study of evolutionary history of groups of organisms
evolution
the theory that describes the way in which organisms evolve or change over many years as a result of natural selection
evidence for evolution
paleontology
comparative anatomy
comparative biochemistry
what is paleontology
study of fossil fuels and the fossil record
what is comparative biochemistry
similarities and differences between the chemical makeup of organisms
fossils
formed when animal and plant remains are preserved in rocks
they form layers and each layer of sediment corresponds to a different geological era
fossil record
forming a sequence from oldest to youngest which shows organisms have changed overtime
why is the fossil record unreliable
not complete and some soft bodied organisms decompose quickly before they fossilise
many fossils are destroyed by earths movements such as volcanos
not the write conditions for fossils
what do fossils tell us
that plants came before animals as the plant fossils appear first
study similarities in anatomy of the fossils to compare how closely related a species is and if they’ve evolved form a common ancestor
allow relationships between extinct and living organisms to be investigated
homologous structure
structure that appears superficially different in different organisms but has the same underlying structure
example of homologous structure
pentadactyl limb of vertebrates
why are vertebrate limbs homologous structures
the basic structure of all vertebrate limbs are very similar so they must of all evolved from a common ancestor
swimming and running and flying limbs are all very similar
what do homologous structures provide evidence for
divergent evolution
divergent evolution
how different species have evolved from a common ancestor but each with a different adaptive features
comparative biochemistry
slight changes in ribosomal dna and cytochrome help identify evolutionary links
look at order of dna bases or order of amino acids in a protein
species closer related have more simular dna and proteins
why is ribosomal RNA used together with fossil information to determine relationship between ancient species
has very slow rate of substitution
interspecific variation
wildest type of variation in between members of different species
intraspecific variation
differences between organisms within a species
2 factors that cause variation
organisms genetic material
environment which organism lives in
genetic causes of variation
alleles
mutations
meiosis
sexual reproduction
chance
how do alleles cause genetic variation
different alleles of a gene produce different affects for a characteristic
how do mutations cause genetic variation
changes in the dna sequence changes the gene which therefore causes a different protein to be coded for
causes different characteristics
if occurs in somatic cell just individual is affected if occurs in gamete offspring is affected
how does meiosis cause genetic variation
produces gametes which receive half genetic content of each parent
info is mixed by independent assortment and crossing over
how does sexual reproduction cause genetic variation
offspring produced from 2 individuals inherits genes from each of the parents so each one therefore differs slightly from their parents
how does chance cause genetic variation
during sexual reproduction its a result of chance as to which 2 combine therefore they differ from their siblings
environmental causes of variation
plants are affected by the amount of light as they can’t move to gain any to grow bigger whereas an animal can move to another area for food or shelter
- scars on your body are caused by environment as occurs due to incident or disease no genetics involved
characteristics that show both environmental and genetic causes
height - parents are tall so you will be tall but a poor diet or disease may stop your growth
skin colour - determined by how much pigment, melanin it contains but if exposed to sunlight you produce more to protect your skin from UV rays
what does a t -test used for
to compare mean value of 2 sets of data
2 types of t test
paired
unpaired
when do you accept the null hypothesis of a t test
if the calculated value is greater than the CV so reject null hypothesis as its not due to chance
spearmen’s rank
adaptations definition
characteristics that increase an organisms chance of survival and reproduction in its environment
anatomical adaptations
physical features
behavioural adaptations
how an organism acts
can be inherited or learnt
physiological adaptations
process that takes place inside an organism
anatomical adaptations
body covering
camouflage
teeth
mimicry
how do body coverings help a species survive
hairs, feathers, scales and shells help organism fly or stay warm - thick hair or protection - snails shell
spikes- deter herbivores
how are teeth adapted
shape and type relate to animals diet
carnivores have sharp canines to kill prey
herbivores have continuously growing molars to chew tough grass
why are some animals adapted to mimicry
copy another animals appearance or sounds to appear poisonous or dangerous to predators despite being harmless
examples of behavioral adaptations
survival behavior’s
courtship
seasonal
survival behavior’s
rabbit freezes when seen
play dead
courtship
elaborate behavior’s to attract a male
scorpions dance to attract partner
increases chance of reproducing
seasonal behavior’s
migration - more from one region to another and back for favorable conditions - better climate/ food source
hibernation - period of inactivity where body temp, heart rate and breathing rate slow to conserve energy reducing requirement of food
2 categories for behavioural adaptations
innate - ability to do this is inherited through genes
behavior’s of spiders to build webs
learned - learnt from experience or observing other animals - use of tools - sea otter use stone to hammer shells off rocks
physiological adaptation examples
poison production - many reptiles produce venom to kill prey or plants produce poison in leaves to protect themselves from being eaten
antibiotic production - bacteria produce antibiotics to kill other species of bacteria in the area
water holding - some frog can store water in its body to allow it to survive in the desert for more than a year without water - cacti
analogous structures
have adapted to perform the same function but have different genetic origin
convergent evolution
when unrelated species begin to share similar traits
evolve due to organisms adapt to similar environments or selection pressures
- whale and fish
examples of convergent evolution
marsupial and placental mice
flying phalangers and flying squirrels
marsupial and placenta moles - both burrow through soft soil to get food both have streamline body shape and modified limbs but differ in fur colour
selection pressures
factors that affect the organisms chance of survival or reproductive success
what organisms are more likely to survive and reproduce
organisms best adapted to their environment
natural selection steps
- organisms within species show variation caused by differences in genes
- organisms whose characteristics are best adapted to selection pressure have increased chance of surviving and reproducing. less well-adapted organisms die or fail to reproduce - survival of fittest
- successful organisms pass on the allele encoding for advantageous characteristic onto their offspring
- process is repeated every generation so overtime proportion of individuals with advantageous characteristic increases so frequency of allele increases in populations gene pool
- over very long periods of time many generations and multiple alleles can lead to evolution of new species
Modern examples of evolution
antibiotic-resistant bacteria
peppered moths
sheep blowflies
antibiotic-resistant bacteria
bacteria reproduce very rapidly so evolve over short period of time
a mutation in dna caused a resistance to methicillin so resistant individuals survived and passed on the allele to offspring but non resistant individuals died
peppered moths
most moths were pale to provide camouflage against light coloured tree bark increasing chance of survival
dark ones were spotted easily and eaten by birds due to a different allele
during industrial evolution trees became darker due to soot and so dark moths were now better adapted as they were more camouflage so they survived and reproduced increasing the frequency of dark moths in the population
sheep blowflies
lay eggs in faecal matter around sheep’s tail- larvae hatch and cause sores
then used pesticide to kill them but they developed a high level of resistance and passed it on as they reproduced
flavo bacterium
live in watse water from factories evolved to digest nylon and so is beneficial to humans to clean up factory waste
beneficial to bacteria as it provides another source of nutrients
