4.3 CLASSIFICATION/EVOLUTION Flashcards
Define binomial system
- A system that uses the genus name and species name to name organisms
State the mnemonic for the modern classification system
Dear
King
Phillip
Cried
Out
For
Goodness
Sake
State the eight taxonomic classification levels
1) Domain
2) Kingdom
3) Phylum
4) Class
5) Order
6) Family
7) Genus
8) Species
State four advantages of the classification system
1) For our convenience
2) Makes studying living things more manageable
3) Easier to identify organisms
4) Help us identify relationships between species
Describe the domain classification level
- There are three domains
1) Archaea
2) Eubacteria
3) Eukaryotae
Describe the kingdom classification level
- There are five kingdoms
1) (Eukaryotes - have a nucleus) plantae, animalia, fungi, protoctista
2) Prokaryotae (no nucleus/single celled)
Describe the phylum classification level
- A major subdivision, contains all the groups of organsisms that have the same body plan (e.g backbone)
Describe the class classification level
- A group of organisms that all posses the same general traits (e.g leg number)
Describe the order classification level
- a subdivision relate to further information about the organism (e.g carnivora or herbivora)
Describe the family classification level
- A group of closely related genra (e.g in carinivora there is cat family and dog family)
Describe the genus classification level
- A group of closely related species
Describe the species classification level
- Members capable of interbreeding, show some variation but are essentially the same
State the trend in relative ease of classification down the taxonomic levels
- Becomes more difficult
State the binomial system name of humans
Homo sapiens
State three disadvantages of the common name method
1) The same organism may have a different common name in different areas/countries
2) The same common name may be used for different organisms in different areas/countries
3) Translation of languages may give an incorrect/different name
State the biological definition and phylogenetic definition of species
Biological = a group of organisms that can freely interbreed to produce fertile offspring
Phylogenetic = a group of individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics
Describe the features of prokaryotae in detail
- No nucleus
- Contain a loop of naked DNA
- No membrane bound organelles
- Smaller ribosomes
- Cells are smaller than eukaryotes
- Can be free living or parasitic
Describe the features of protoctista in detail
- EUKARYOTES
- Most are single celled
- Have autotrphic or heterotrophic nutrition
- Mostly free living
- Show a very wide variety of forms
Describe the features of fungi in detail
- EUKARYOTES
- Chitin walls
- Mostly free living and saprophytic
- Has many nuclei in the cytoplasm
- Can exist as single cells or mycelium (with hyphae)
Describe the features of plantae in detail
- EUKARYOTES
- Are multicellular
- Have cellulose cell wall
- Are autotrophic
- Contain chlorophyll
Describe the features of animalia in detail
- EUKARYOTES
- Are multicellular
- Are heterotrophic
- Able to move around
Define convergent evolution
- When unrelated species look very similar because of the similar ways in which they have adapted to their environment
State which process causes slight differences in biological molecules between organisms
- Evolution
Explain how the extent of similarity/difference in versions of the same biological molecules can determine evolutionary relationships
- Two organisms with very different versions of the same molecules are less closely related because they have evolved separately for longer
- Two organisms with very similar versions of the same molecules are more closely related because they have not evolved separately for long
Describe the evidence that cytochrome c gives about evolutionary relationships
- If the amino acid sequence of cytochrome c is the same, the two species are closely related
- If the amino acid sequence of cytochrome c is the different, the two species are not closely related
- (the more differences the less closely related)
State and explain the type of organsism that cytochrome c is present in
- ALL organisms that respire because its the protein used in respiration
Define genetic code
- The instructions for producing proteins
Explain how DNA can be used as evidence for evolutionary relationships
- The more similar the sequence in a part of DNA, the more closely related the two species
- Because they have not evolved separaetly for a long time
State the three-domain classification system
1) Bacteria
2) Archaea
3) Eukaryotae
State structural differences between the bacteria against archae and eukaryotae in the three domain classification system
Bacteria have:
1) A different cell membrane strcuture
2) Flagella
3) Different organelles
4) No proteins associated with their genetic material
5) A different mechanism for DNA replication and for synthesising RNA
6) Different enzymes used to synthesise RNA
State structural similarities between the archae and eukaryotae in the three domain classification system
Archae and eukaryotae both have:
1) Similar mechanisms for DNA replication and synthesising RNA
2) Production of proteins that are associated with their DNA
3) Similar enzymes used to synthesise RNA
Define phylogeny
- The study of evolutionary relationships between organisms (how closely different species are related)
Define artificial classification and natural classification
Artificial classification = classification based on a few characteristics for human convinience, in a way thats easy to remember/find
Natural classification = classification that reflects the real evolutionary relationships between organisms (e.g the modern classification system)
Compare four features of artifcial classification against natural classification
Artificial classification:
1) Based on only a few chracteristics
2) Does not reflect evolutionary relationships
3) Provides limited information
4) Doesnt change
Natural classification:
1) Based on many chracteristics
2) Reflects evolutionary relationships
3) Privides useful information
4) Changes alot with advancing information
Define monophyletic species
- A group of species that belong to the same phylogenetic group and share a common ancestor
State the four observations that darwin made
1) Offspring genrally appear similar to their parents
2) No two individuals are identicle
3) Organisms have the ability to produce large numbers of offspring
4) Populations in nature tend to remain a fairly stable size
State darwins conclusions
- There is struggle to survive
- Better adpated individuals survive and pass their characteristic to the next generation
- Overtime, a number of changes may give rise to a new species
Describe how variation leads to evolution according to darwins research
1) When too many young are produced, there is competition for food/resources
2) As offspring are different, some may be better adapted than others
3) The better adpated individuals obtain enough food/resources to survive long enough to reproduce
4) They then pass these advantagous characteristics onto the next generation
5) The population can change/evole to become better suited to its environment
State and explain the two pieces of evidence for evolution
1) Fossil evidence (fossil species are similar to current species but current species seem to be better adpated)
2) Biological molecules (If one species gives rise to another they are likey to have the same biological molecules/two closely related species will have only separated relatively recently so their biological molecules will be identical or similar)
Explain how fossils can give evidence for evolution
- Fossils show change overtime
- There are methods to date fossils
- They show relationships between species/organisms
- Fossil species are similar to current species but current species seem to be better adpated
Expain how biological molecules can give evidence for evolution
- If one species gives rise to another they are likey to have the same biological molecules
- Two closely related species will have only separated relatively recently so their biological molecules will be identical or similar
- (e.g Cytochrome C and DNA gene sequences)
State and explain how mitochondrial DNA provides evidence for natural selection
- During sexual reproduction the mitochondrial DNA in the egg is passed down to the offspring
- ONLY maternal mDNA is passed to offspring, NEVER the paternal mDNA
- We can trace back an organisms mDNA to determine migration patterns (shows change)
Define variation
- The differences between individuals
State the six different forms of variation
1) Interspecific variation
2) Intraspecific variation
3) Environmental variation
4) Genetic variation
5) Continuous variation
6) Discontinuous variation
Define intraspecific variation
- The variation between members of the same species (e.g different niches for each member)
Define interspecific variation
- The differences between different species (e.g different behaviour between cats and dogs)
Define enironmental variation
- Variation caused by response to environemntal factors (e.g light intensity)
Define genetic variation
- Variation caused by the possesion of different allele combinations (e.g blood group)
Define continuous variation
- Variation where there is two extremes and a full range of values inbetween (e.g human height, tree leaf length, flagella number on bacteria)
Define discontinuous variation
- Variation where there are distinct catergories and nothing inbetween (e.g sex, human blood groups, weather bacteria have flagella or not)
State how to show CONTINUOUS variation in data form
- A histogram
State how to show DISCONTINUOUS variation in data form
- A bar chart
Give an example that describes how environemtal factors could be limited by genetic factors
- Regardless of how nutritional your diet is, you may be unable to grow tall is yout height is limited by your genes/genetics
Give an example that describes how genetic factors could be limited by environemntal factors
- Not all genes are active all the time, certain environmental factors can active/deactivate gene expression
Define adaptation
- A characteristic that enhances survival in the habitat
State four things a well-adapted individual will be able to do
1) Find food/photosynthesise well
2) Defend itself from predators/disease
3) Survive the abiotic factors of its environement (e.g temperature/water availibility/pH/light)
4) Resond to changes in its environment
State the three types of adaptation
1) Anatomical adaptations
2) Behavioural adaptations
3) Physiological adaptations
Define anatomical adaptation
- Internal/external structural features
Define behavioural adaptation
- The ways that behaviour (response to change) is modified for survival
Define physiological adaptation
- Ensuring functioning of processes are occuring at the cellular level
State and explain five anatomical adaptations of marram grass
1) Long/widespread roots - enables sufficient water/nutrient absorbance and stabilises sand dunes
2) Curled leaves - reduces the SA of the leaf that is exposed to the wind thus moisture builds up
3) Waxy cuticle - reduces the water wavpour loss by evaporation
4) Hairs on lower epidermis reduces air movement so water vapour is retained close to the lower epidermis
5) Fewer stomata means less water vapour loss
State and explain the two behavioural adaptations of marram grass
1) Rolling the leaf more tightly and closing the stomata when there is a shortage of water to reduce transpiration
2) When covered by sand it will grow faster to reach sunlight
State and explain four biochemical (physiological) adaptations of marram grass
1) Specialised hinge cells lose water/turgidity which allows for the leaf to curl up as a response to low water availability
2) Guard cells control opening and closing of stomata via turgidity
3) Maintains a lower water potential than normal plants to enable survival in salty conditions
4) Leaves contain many lignified cells that provide support when turgidity is lost so leaf stays upright even when water is unavailable
State the similarities of marsupial and placental moles
- Cylindrical body
- Small eyes
- Strong front legs
- Large claws on front legs
- Short fur
- Short tail
- Tough skin nose
Explain covergent evolution
- When different species occupy similar environments
- Similar selection pressures
- Results in selection for similar adaptations
- Thus, the different species end up looking more similar than they genetically are
Outline the process of natural selection
1) Mutations create alternative alleles
2) This creates genetic variation between a species (intraspecific variation)
3) Scarce resources create selection pressure
4) Individuals with an advantageous characteristic will survive and reproduce
5) Their offspring then inherit that advantageous allele
6) The next generation will have a higher proportion of individuals with the advantageous characteristics
Give an example of a selection pressure
- Exposure to pesticides/insecticides/antibiotics
