Chapter 10 Classification and Evolution Flashcards
What is classification?
The process by which living organisms are sorted into groups
Why do scientists classify organisms?
Identify species and where they belong
Predict characteristics of other organisms in the group
To find evolutionary links, common ancestors?
What is a taxonomic group?
The hierarchal (formed of lots of smaller groups in sequences) groups of classification
What is a species?
The smallest group in which two organisms can reproduce to produce fertile offspring
How do you name organism? What is the system called and what is each part known as?
Genus species
Italics or underlined
First letter of genus capitalised, rest lower case
Binomial nomenclature
Genus= general name Species= specific name
What are the five kingdoms?
Animalia
Plantae
Fungi
Protoctista
Prokaryotae
What are the differences between prokaryotae and protoctista?
Both are unicellular but protocista contain a nucleus and membrane bound organelles
What are some features of fungi?
Uni or multi cellular
Nucleus, membrane bound organelles, Chitin cell wall
Saprophytic feeders
Glycogen
What type of feeders are animals and plants?
Animals are heterotrophic feeders, ingest others
Plants are autotrophic feeders, make own food
What are the three domains?
Eukarya
Archaea
Bacteria
What did Woese use to classify the domains?
The number of proteins in RNA polymerase, and mitochondria size
Eukarya= 12 80s
Archae= 8-10 70s
Bacteria= 5 70s
What are the differences between archae and bacteria?
Archae have 8-10 proteins in RNA polymerase, cell walls without peptidoglycan, ether lipids, and similar transcription to eukarya
Mostly found in extreme conditions
Bacteria have 5 proteins in RNA polymerase, peptidoglycan, ester lipids, and operons for transcription
Found in everyday conditions
What is the domain of protocista?
Eukarya
What is phylogeny? How is it related to classification?
The study of evolutionary relationships between organisms
The closeness of the evolutionary relationships between organisms is used to determine grouping. Closer relationship, move likely overlap in taxonomic groups.
What are the advantages of phylogenetic classification?
Gives evolutionary history, and so species linkage, rather than placing into groups
Includes time to compare how long a species has been present
Used to test evolutionary relationships between organisms and predict new divergence
What is the main evidence of evolution?
Palaeontology, using fossils and comparing anatomy
Comparative Biochemistry, using similarities in biomolecules
How do fossils support the theory of evolution?
Simplest organisms in oldest rocks e.g bacteria and invertebrates, vertebrates and complex in more recent, developing to more complex over time
Sequence matches order, plants needed for animals
Comparing anatomy within the fossils to see which fossils are related, and compare this anatomy to species still present today
Establish relationship to current day species, so related.
What are homologous structures?
Structured which appear superficially different in different organisms but have the same underlying structure
Suggests divergent evolution
How do you use comparative biochemistry to show relationships between organisms?
Look at the amino acid sequence of molecules resistant to change such as Cytochrome C and rRNA
The more similar the amino acid sequence, the closer related the organisms
Look at the base sequence of DNA
The more similar the base sequence, the closer related the organism
Works as most substitutions neutral, highly conserved, so would not affect function greatly but can show divergence into species
What are the types of variation?
Interspecific Variation- between members of different species
Intraspecific Variation- between members of the same species
What are the genetic causes of variation?
Mutations, Alleles forming
Meiosis:
- crossing over between non-sister chromatids in prophase 1, recombinant
- independent assortment in metaphase
Sexual Reproduction with two sets of allele passed to the offspring
Random chance of which gametes will be fused
How are continuous and discontinuous variation displayed?
Continuous- histogram without bars with line of best fit, normal distribution
Discontinuous- bar charts
What are the three types of adaptations?
Anatomical- physical features
Behavioural- the way the organism acts
Physiological - processes that take place in the organism
What are adaptations?
Characteristics which increases an organisms chance of survival and reproduction in its environment
What are analogous structures? Why do they arise?
Structures which perform the same function but genetic origins/ details are different
Due to organisms sharing a similar niche, resulting in similar characteristics
Suggests convergent evolution
What is convergent evolution?
Unrelated species start to show similar characteristics due to selection pressures, environment…
E.g Marsupial and Placental Moles both burrow in soft ground, velvety fur,
When are paired t-tests used?
When the same sample is being tested before and after a test
e.g Results of Students in School A tested before and after eating
Uses the differences in the sample for the equation
I guess can be happen, can be paired to itself as it is itself
What is the kingdom of algae?
Protocista as even through they are autotrophic, they are unicellular so cannot be plants
What are examples of anatomical adaptations?
Body coverings such as hair, scales and spines, to help stay warm and provide protection
Camouflage- harder for predators to find them
Teeth- shape related to diet, molars vs canines
Mimicry- copy appearance of more dangerous species e.g milk Vs coral snake
What are examples of behavioural adaptions and how do they help?
To help survival such as playing possum
Finding partners- dances like scorpions and peacock
Seasonal behaviour to cope with changing climates, migration
What are the two types of behavioural adaptations?
Learned- learnt in life, such as use of tools
Innate- from genes, such as spiders building webs
What are examples of physiological adaptations and how do they help?
Poison production to prevent being eaten
Antibiotic production to kill bacteria
Why may organisms form different taxonomic groups share similar characteristics? Give an example
An example of convergent evolution, where the environment and selection pressures have led to shared characteristics, analogous structures
E.g Marsupial Moles and Placental Moles both burrow and are streamlined, despite living in separate countries as environments are similar
What are selection pressures?
Factors that affect an organisms chance of survival or reproductive success
What is the mechanism of natural selection?
Organisms display variation, caused by mutations. Organisms whose characteristics are advantageous to survival, have increased chance of survival and reproducing successful, with these advantages genes passed to their offspring
Less adapted organisms die and fail to reproduce, in survival of the fittest
Depending on nature of allele, may reduce likelihood of a non allele breeding with an allele
This process is repeated over generations, increasing the proportion of organisms with the allele
Leads to the production of a new species as genetic differences to great to interbreed
Give examples of how evolution of other organisms has affected humans?
Flavobacterium- digest nylon by gene duplications and frame shift, helps environment
Anti biotic resistance- MRSA, DNA altered during replication, resistant to antibiotics, over time on this allele remains
Blowflies and diazinon- resistance to pesticide and pass on alleles for it
What are the 6 kingdoms, following from the 3 domains?
Eubacteria
Archaebacteria
Plantae
Animalia
Fungi
Protocista
Why might divergent evolution occur?
A change in habitat/ loss of/ or migration
When a common ancestor will evolve to form two different species with a different set of characteristics
What causes variation?
Differences with the genetic material of an organism compared to others- alleles, mutations, meiosis, sexual reproduction so individual is different to its parents as inherits from both. Chance.
Environment the organism lives in- plants, positioning, scars,
Most a mix of both
What is the difference between the type and pattern of variation?
Type= intra/interspecific variation
Pattern= continuous, discrete
Why do bats and birds both have wings but these are classified as analogous structures?
Similar niches
So in intraspecific competition with each other, similar selection pressures
Wings advantageous to both to survive and consume prey
What are disadvantages of phylogenetic trees?
Assumes that traits are from common ancestors but can evolve randomly
Needs accurate date, cannot be limited
How do fossils tell us about timings of organisms? What are disadvantages of using fossils?
The deeper the fossil, the longer it has been present, so the older the organism
The fossil record is not compete record, could be destroyed, not fossilised at the time, or waiting to be discovered
How do you calculate degrees of freedom for paired and unpaired t-tests?
Paired- n in population -1
Unpaired- n in populations (both) -2
When do you use t-tests?
When comparing the means of two different samples, or the same sample before and after
How do you set out a t-test?
State null hypothesis: assume there is no significant statistical difference between the factors
State alternative hypothesis
Carry out test with means and standard deviations
Compare calculated value to degrees of freedom value
If calculated>d of f, there is less than a 5% probability the results have occurred due to chance, so there is a significant difference between the factors
If calculated<d of f, there is more than a 5% probability the results have occurred due to chance, so there is not a significant difference between the factors
When do you use paired and unpaired t-tests?
Paired- same sample, before and after a certain condition e.g at 20 degrees vs 40
Unpaired- 2 different samples, in certain conditions, e.g 2 different colonies of bacteria tests in blue light
Generally always paired
What tables do you use for Spearman’s rank?
Only with N rather than d of e
N=number of pairs used
What are the differences and similarities between marsupial moles and placental moles?
Marsupial moles- the embryo moves into the marsupium (pouch) where it will continue to develop
Placental moles- placenta connects the embryos to its mother circulatory system, continue to grow to maturity
However, both are similar due to similar niches. Both burrow, streamlined body, velvety fur and so an example of convergent evolution (one lives in Australia, the other in North America)
What can you conclude about significance from a percentage change of 5%?
Nothing about significance
Need to perform a statistical test
What is the degrees of freedom value for chi squared?
N-1
Where N is the number of categories, e.g if flowers are white, pink, and red, n=3
