Classification and Evolution Flashcards
List the taxonomic hierarchy of biological classifications
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species
Define the term classification
Placing living organisms into groups based on their similarities & differences
What is taxonomy?
Study of the principles of classification
State 4 reasons why scientists classify organisms
-Identify species
-Predict characteristics
-Study organisms
-Find evolutionary links (share characteristics bc evolved from common ancestor)
Name the 3 domains
-Archaea
-Eukarya
-Bacteria
What is a species?
Group of organisms very similar in anatomy, physiology, biochemsitry & genetics
Why do we need binomial names?
-Diff common names used in diff countries
-Diff languages
-Same common name may apply to diff species
-Provides universal language to talk about species
Name the 5 kingdoms
-Prokaryotae
-Protoctista (Protist)
-Fungi
-Plant
-Animal
State 3 differences between archaebacteria and eubacteria
-Diff enzymes for building RNA
-Diff mechanisms for DNA replication & building DNA
-Diff cell surface membrane structure & flagella w/ diff internal structure
State 3 similarities between archaebacteria and eukaryotes
-Similar enzymes for building RNA
-Similar mechanism for DNA replication & building RNA
-Production of some proteins that bind to their DNA
Give an example of a) a unicellular fungi and b) a multicellular fungi
a) Yeast
b) Mushrooms
Out of the 5 kingdoms which ones are eukaryotic?
-Protist
-Fungi
-Plant
-Animal
State which kingdoms are composed of unicellular organisms and which are composed of multicellular organisms
-Prokaryote: U
-Protist: some U, some M
-Fungi: some U, some M
-Plant: M
-Animal: M
State the type of DNA found in each of the kingdoms
-Prokaryote: Naked DNA/plasmids
-Rest: Chromosomes in nucleus
State the type of ribosomes each of the kingdoms have
-Prokaryote: 70s
-Rest: 80s
State whether the organisms in each of the 5 kingdoms have a cell wall or not
-Prokaryote: Yes, made of peptidoglycan
-Protist: Can have one (varies)
-Fungi: Yes, made of chitin
-Plant: Yes, made of cellulose
-Animal: No
State how each of the 5 kingdoms gain nutrition
-Prokaryote & protist: Either
-Fungi & animals: Heterotroph
-Plant: Autotroph
State the 2 kingdoms where the organisms may have chlorophyll
-Plants
-Protists
What is phylogeny?
Study of evolutionary relationships between organisms
State 4 pieces of evidence that can be used to classify organisms
-Genetics
-Anatomy
-Biochemistry
-Physiology
What are homologous structures?
-Have similar anatomy
-Share connection to common ancestor
What are analogous structures?
-May have similar function
-But diff evolutionary origin
Explain why using anatomical features alone to classify organisms can be problematic
-Convergent evolution: Evolution of similar traits in distantly related organisms
-Divergent evolution: Organisms w/ common ancestor evolve differences & become diff species
Describe how molecular evidence can be used to clarify relationships between organisms
-Proteins/RNA/DNA because all have sequences
-The more similar DNA base sequences the more closely related 2 species are
-The more diff the longer it has been since they shared common ancestor
State the cause of changes to DNA base sequences
Mutations
Describe a limitation to using molecular evidence to clarify the relationships between organisms
-If there were prior mutations which later changed back to original base, we wouldn’t know it changed
-e.g. Original = A, then changed to T, then C, then back to A
Explain how fossils are created
-Organism dies (preferably in anoxic environ)
-Sedimentation (layers of silt/sediment over organism)
-Gradually organism = replaced by minerals
-Fossil forms
What is meant by the term anoxic?
Low O2
Explain why carbon dating is not a suitable measure of how old a fossil is
C is replaced by minerals
Explain what is meant by the term monophyletic
Organisms belong to same phylogenetic group
Compare interspecific & intraspecific variation
-Inter: Variation between diff species
-Intra: Variation within species
What is variation?
Diff in characteristics between organisms
Describe the process of natural selection
-Spontaneous + random mutation -> diff versions of genes (alleles)
-Creates genetic variation between individuals of species (intraspecific variation)
-Once variety exists, environ ‘selects’ certain characteristics/alleles (selection pressure)
-Individuals w/ advantageous characteristics more likely to survive + reproduce (natural selection)
-Pass on advantageous characteristics (inheritance)
-Next gen = higher proportion of individuals w/ successful characteristics (allele frequency)
-Over t, organisms become well adapted to environ (adaptation)
Suggest why the fossil record is not complete
Not everything fossilises
What are vestigial characteristics?
-Anatomical features that no longer serve function
-Evidence of evolution
What is the fossil record?
-Diff fossils found in diff layers of rock (strata)
-Showing organisms have gradually changed over t
Explain how the fossil record provides evidence for the theory of evolution
-Simpler organisms found in older rocks, more complex in newer rocks
-Sequence matches ecological links
Explain why phylogenetic classification is an improvement from Linnean classification
-Based on common ancestors using biochemical/genetic evidence
-Based on evolutionary relationships
-Doesn’t force species into false groups
-Takes into account time
State 4 genetic causes of variation
-Mutations
-Alleles
-Meiosis (crossing over, independent assortment)
-Sexual reproduction
State 6 environmental causes of variation
-Access to nutrients
-Light intensity
-Injury/damage
-Disease
-Climate (temp, rainfall etc.
-Activity level
Compare continuous and discontinuous variation
Continuous
-2 extremes & full range of intermediate values between them
-Controlled by genetics + environ
-Graphical representation: histogram
Discontinuous
-2 or more distinct group w/ no intermediate values (discrete variables)
-Controlled by genetics
-Bar chart
State the formula for standard deviation
square root of (sigma(x-mean of x)squared/n-1)
n=no. data points (sample size)
State the formula for the rate of reaction
1/time
Give examples of continuous variation in animals (2), plants (3) and microorganisms (1)
a) aHeight
-Foot size
b) -Size of guard cell
-Leaf size
-Plant height
c) -Bacterial colony size
Give examples of discontinuous variation in animals (2), plants (2) and microorganisms (1)
a) -Blood type
-Eye colour
b) -Flower colour
-Seed shape
c) -Spore formation (in fungi some strains form spores others do not)
Why might organisms from different taxonomic groups show similar anatomical features?
