Incomplete - 10 - Classification and evolution Flashcards
Why is there a standardised system for classification?
- same language
- identify new species
- evolutionary links
What is a species?
a group of similar organisms with certain features in common and similar genes
capable of naturally interbreeding and producing fertile offspring
What is the name for the classification system we use?
phylogenetic classification
How is the classification system organised?
by how closely they are related
what is the order to the taxonomies in classification?
kingdom phylum class order family genus species
As you go down the classification system what happens to the number of organisms and the similarities?
fewer organisms, greater similarities
how do we write the binomial nomenclature of a species?
genus + species
capital for genus, italics for species
Name the 5 kingdoms in the 5 kingdom system?
prokaryotae Protoctista fungi Plantae animalia
Name the 3 domains in the 3 domain system
bacteria, archaea, eukarya
name the 6 kingdoms in the 3 domain system
eubacteria, archaebacteria, protoctists, plantea, fungi, animalia
define autotrophic
an organism that obtains its nutrients itself ie. via photosynthesis
define heterotrophic
an organism that obtains its nutrients from ingesting other organisms
define saprotrophic
an organism that secretes extracellular enzymes ad absorbs soluble molecules to obtain its nutrients
What did Woese study to come up with his 3 domain system?
- ribosomal RNA sequences
- membrane lipid structure
- sensitivity to antibiotics
Describe the features of a prokaryote in terms of:
- cell wall
- genetic material
- nutrition
- motility
peptidoglycan
circular DNA (not membrane-bound, no histones or chromosomes)
absorbs nutrients from its surroundings - diffusion
some move with a flagella
divide by binary fission
Describe the features of a Protoctista in terms of:
- cell wall
- genetic material
- nutrition
- motility
- no cell wall
- DNA in the nucleus
- some autotrophic some heterotrophic
- flagella, pseudopods or cillia
- eukaryotic and unicellular
Describe the features of fungi in terms of:
- cell wall
- genetic material
- nutrition
- motility
- DNA in the nucleus
- chitin cell wall
- sapprophitic, store as glycogen
- no motility
- reproduce by spores (either sexual or asexual reproduction)
Describe the features of a plant in terms of:
- cell wall
- genetic material
- nutrition
- motility
- DNA in nucleus
- cellulose cell wall
- autotrophic, store as starch
- no motility
- eukaryotic
Describe the features of an animal in terms of:
- cell wall
- genetic material
- nutrition
- motility
- DNA in nucleus
- no cell wall
- heterotrophic, most have gut, store as glycogen
- motility through muscles and nervous systems
- eukaryotic
2 descendants on a phylogenetic tree split directly from same node are called…
sister groups
nodes/ where lines join on a plhylogenetic tree represent
common ancestors
What does an extinct species look like on a phylogenetic tree?
a line that does not continue to the present (often perpendicular to line of time)
How do different species evolve?
mutations in dna
leads to change in gene
COULD cause a change in phenotype if different amino acid is produced
Why do mutations not always change the phenotype of a species?
DNA is degenerate code
change in base could lead to the same amino acid
what evidence is used for the construction of phylogenetic trees?
- compare DNA sequencing
- compare amino acid sequencing
- fossil evidence
What evidence is there for evolution?
- shared characteristics/behavoir
- fossil evidence
- comparative biochemistry
- evolutionary throw-backs
- antibiotic resistance
- comparative anatomy
- evolutionary embryology
What is evolution?
The slow continued change of organisms over hundred of years
What are fossils?
remains of organisms from millions of years ago often found in rocks or amber
What can fossils be of, why are they found?
1 - from parts of organisms that have no decayed because one or more of the conditions were not present
2 - parts of the organism replaced my minerals
3- traces eg. footprints
What did Charles Lyell do?
collected fossils
proposed fossils were dead organsims that lived millions of years ago
What did Charles Darwin do?
proposed evolution by natural selection
What did Darwin propose evolution by natural selection was?
- individuals in a species show a wide range of variation
- individuals ina. species always have more offspring than the environment can support
- those with characteristics most suited to the environment survive
- pass characteristics onto offspring, causes a gradual change over time
How has our understanding of evolution by natural selection changed since Darwin?
We now understand genes and alleles being passed on, these pass on the favourable characteristics
What did Alfred Russell Wallace do?
- peer review Charles Darwins work
- joint publish the theory of the origin or species
How do fossils support the theory of evolution?
can date organisms
- -older fossils at the bottom are less complex
- -therefore fossils have been there for millions of years simple life forms evolve into more complex ones
NEED TO FINISH ONCE I HAVE NOTES
Why are fossil records not always complete?
- soft-bodied organism will not fossilise
- fossils damaged or destroyed by geological activity
- gaps if conditions were not right for a period of time
- not been discovered yet
