10 - Classification and evolution Flashcards
Species
A basic unit of of classification.
All members of a species show variations, but are essentially the same.
Occupy the same niche
Domain
Highest taxonomic hierarchy rank.
3 domains : Archaea, Eubacteria and Eukaryotae
Taxonomic hierarchy
Kingdom, phylum, class, order, family, genus and species
The binomial system
A system that uses the genus name and the species to avoid confusion when naming organisms.
This avoids the confusion because all the scientists in every country will use the same name
Describe a prokaryotae
Unicellular
No nucleus or other membrane bound organelles
No visible feeding mechanism, nutrients or absorbed to the cell wall
Describe a protoctista
Eukaryotic
Mostly single-celled (algae = multicellular)
Some photosynthesise (AUTOTROPHIC)
Some ingest prey (HETEROTROPIC)
Describe a fungi
Eukaryotic Single-celled / multicellular Most have a body of mycelium Absorption from decaying materials (SAPROPHYTIC)
Describe a plantae
Eukaryotic
Multicellular
A nucleus or other membrane bound organelles
Some photosynthesise (AUTOTROPHIC)
Describe animalia
Multicellular
A nucleus or other membrane bound organelles
Move with the aid of cilia, flagella and proteins.
The evidence that has led to new classification systems
Originally classification systems were based on observational features
Now through the study of genetics and other biological molecules scientists can now study the evolutionary relationship between organisms and then classify organisms
The three
domains of life
The three domains are; Archaea, bacteria and eukarya
Each domain contains a unique form of RNA and different ribosomes
Archaea
Have 70s ribosomes
RNA polymerase of different organisms contain between 8 and 10 proteins
Bacteria
Have 70s ribosomes
RNA polymerase contains 5 proteins
Eukarya
Have 80s ribosomes
RNA polymerase contains 12 proteins
Phylogeny
Study of evolutionary relationships between organisms.
It reveals which groups of organisms are related to each other and how closely related
Advantages of phylogenetic classification
Phylogeny uses a continuous tree whereas classification requires discrete taxonomical groups therefore scientists do not have to put organisms into a specific group that they may not fit
Developing the evolution theory -
Before Darwin
IN 1809 - Most people believed in literal sense (the bible)
IN 1831 - Charles Lyell suggested fossils were evidence of animals that lived years ago.
Developing the evolution theory -
After Darwin
Darwin carry out some observation on finches in the Galapagos Islands
He noticed that different Islands had different type of finches that the birds were similar in many ways so they are closely related but their beaks and claws with different shapes
These observations Darwin realise that the Finches beats will link to the food availability on the island
The birds whose beak was adapted with survive longer than the bird whose beak was less suited
These birds will have more offspring and therefore all the finches on the island should all have the same characteristics, over time
IN 1858 - Wallace and Darwin had very similar research so they joined together to publish their theories - which was natural selection.
Which was very controversial at the time as the wide Christian believe is that God created man and all else
Evidence of Evolution
Paleontology is the study of fossils and fossil records
Comparative Anatomy is the study of similarities and differences between organisms anatomy
Comparative biochemistry is the similarity and differences between the chemistry makeup of organisms
Variation
The differences between individuals
Continuous variation
Where there are two extremes full of range of values in between
Discontinuous variation
With a distinct categories and nothing in between
Environmental variation
Variation caused by response to environmental factors
Genetic variation
Variation caused by possessing a different combination of alleles/ mutations/ meiosis
Intraspecific variation
The variation between members of the same species
interspecific variation
The difference between species
Adaptation
The characteristic that enhances survival in a habitat
Anatomical adaptation
Structural features that have been adapted to help survival
E.g. Body coverings Camouflage Teeth Mimicry
Behavioural adaptations
The way that behaviour is modified for survival
E.g.
Courtship
Seasonal Behaviours : Migration/ Hibernation
Psychological adaptations
Processes that take place inside an organism
E.g.
Poison production
Antibiotic production
Water holding
Convergent evolution
When unrelated species begin to share similar traits. These similar traits evolve because the organisms adapt to similar environmental factors
E.g. Moles: cylinder body small eyes strong front legs with claws short tail/fur nose with tough skin
How does natural selection work?
Mutation create alternative versions of a gene. This creates genetic variation between the individuals of a species. When resources are scarce the mutation that is advantageous with show this is selection pressure.
Individuals with an advantageous characteristics for survive and reproduce therefore they will pass on their advantageous characteristics. The next-generation will have a higher proportion of individuals with the successful characteristics.
How are humans effected by evolution?
INSECTS
Insects have evolved so that they are resistant to pesticides. This affects humans because because they eat and damage crops.
They can also act as effective as transmitted pathogens.
More insecticides must be used on the crops to then kill the insects which means humans will consume more insecticides on crops that haven’t being effected
How are humans effected by evolution?
MICROORGANISMS
When antibiotics are used the kill most of the bacteria
Bacteria survive or become resistant when people stop taking antibiotics these bacteria can reproduce create a batch of bacteria that are resistant to the drugs. Overuse and incorrect use of antibiotics leads to bacteria being resistant to all antibiotics
MRSA
Some bacteria have gained a particularly wide range of resistance they are called MRSA.
This bacterium has developed resistance due to an ever-increasing range or stronger drugs. This is an example of an ‘Evolutionary Arms Race’ where medical researchers are struggling to develop new and effective drugs but the bacterial population becoming more resistant.
A distribution curve is said to be normal when
The mean mode and median are the same
The distribution has a bell shape and a symmetrical
Most of the values lie closer to the mean
Spearman’s Rank Correlation Coefficient
No correlation
Positive correlation
Negative correlation
Student’s t-test
A test used to compare two means
