4.3 Classification And Evolution Flashcards
What is the taxonomic hierarchy?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Describe the binomial naming system
Two part
Genus + species (in italics/underlined)
Genus = Capital
Species = lowercase
What are the 5 kingdoms?
Prokaryotae
Protoctista
Fungi
Plantae
Animalia
Describe prokaryotae
No membrane bound organelles
Peptidoglycan cell wall
Naked DNA
Unicellular
External digestion: heterotrophic, autotrophic, saprotrophic
Describe Protoctista
Eukaryotic
Membrane bound organelles
Cell wall
Heterotrophic and autotrophic
Unicellular or multicellular
Describe Fungi
Eukaryotic
Membrane bound organelles
Chitin cell wall
Heterotrophic and saprotrophic
Reproduce by releasing spores from hyphae in mycelium
Multi/unicellular
Multinucleated cytoplasm
Describe plantae
Eukaryotes, membrane bound organelles, cellulose cell wall, autotrophic (photosynthesis), multicellular
Describe Animalia
Eukaryotic
No cell wall
Heterotrophic
Multicellular
Mobile
Membrane bound organelles
What evidence has led to new classification systems?
Observable/morphological features
DNA based sequences
Biochemistry: proteins (RNA polymerase and cytochrome C)
Amino acid sequence
Ribosomal RNA
Behaviours (feeding, predatory, courtship)
Shared phylogeny
What are the three domains?
Bacteria, Archaea, eukaryotes
Describe bacteria
Prokaryotic, peptidoglycan cell wall, less complex RNA polymerases than eukaryotes, different amino acids in protein synthesis, circular chromosomes and plasmids, no histones, no organelles
Describe archaea
Prokaryotic, no peptidoglycan cell wall, complex RNA polymerases, circular chromosomes and plasmids, has histones, no organelles
Describe eukaryotes
Eukaryotic, cell wall in plants and fungi: polysaccharide, complex RNA polymerases, linear chromosomes, histones, organelles, larger ribosomes
Relationship between classification and phylogeny
Classification: placing organisms into groups/categories based on similarities and differences
Phylogeny: closeness of evolutionary relationships
Modern taxonomic classification reflects phylogeny
What did Darwin find?
Offspring look like parents
No two individuals are identical
Organisms produce large numbers of offspring
Populations in nature remain fairly stable
Evidence for theory of evolution by natural selection
Fossils, DNA, biological molecules
Define intraspecific and interspecific variation
Intraspecific: variation within a species
Interspecific: variation between species
Describe continuous variation
No distinct categories, polygenic, affected by environment, intermediate values
Describe discontinuous variation
Distinct categories
Determined by one or few genes
Unaffected by the environment
No intermediate values
What are anatomical/structural adaptations?
Structures that increase chances of survival
What are physiological adaptations?
Processes in cells which increase chances of survival
What are behavioural adaptations?
Change in behaviour to aid survival
What are homologous structures?
Same evolutionary origins regardless of their functions in the adult of a species e.g. pentadactyl limb
What are analogous structures?
Different structures similar functions
Define divergent evolution
Species have the same common ancestor and share similar characteristics
Describe convergent evolution
Species which are not closely related adapt in similar environments to fulfill the same niche so share similar characteristics e.g. marsupial and placental mole
Describe the process of evolution by natural selection
Genetic variation
Due to mutation
Mutation is random
Sexual selection
Large numbers of offspring
Selection pressure
Those with advantageous mutation more likely to survive and reproduce
Pass on allele/inherited by offspring
Overtime, increase in allele frequency
