Topic 3 Classification And Biodiversity Flashcards
4 eukarya kingdoms
Animalia
Plantae
Fungi
Protoctista
3 facts about Plantae
- autotrophs
- contain chlorophyll for photosynthesis
- cellulose cell walls
3 facts about Fungi
-saprophytic
- chitin cell wall
- reproduce by spores
3 facts about Animalia
- heterotrophic
- capable of whole body movement
- no cell walls
What are Protoctista ?
- diverse group of eukaryotes that cannot be classified as animals, plants or fungi.
What are autotrophs?
Plantae
Make their own food
What are heterotrophs?
Animalia
They eat others for food
What are saprophytes?
Fungi
Live off dead organisms using extra cellular digestion
What are the Taxonomic groups?
D Keep Ponds Clean Or Froggies Get Sick / Daddy King Philip Came Over For Great Sex
Domain Kingdom Phylum Class Order Family Genus Species
What is the definition of a species?
A group of organisms with similar characteristics that interbreed to produce fertile offspring
What is sexual dimorphism?
Male and female look very different
Have different physical features
What are morphological species?
Organisms categorised together as a species based on their physical features
Advantage of morphological species?
Easy
Disad of morphological species
Problem of sexual dimorphism
Limitations of species models?
- Need to find evidence
Rare to see them mating/ Expensive to setup sreeding programs - Seperate species can produce fertile offopring
- mary organismes dont reproduce sexually
- fossil organism, cannot reproduce but need to be classified
What is a phylogeny
Study of evolutionary relationships
Closeness of relationship between organisms which create an evolutionary tree
What is the redefined species definition? Based on …
- structural and biochemical resemblance
- capability to interbreed and produce fertile offspring
- they do NOT interbreed w other species
What are the 3 domains
- bacteria
- eukaryotes
- archaea
(ABE)
How are scientific ideas evaluated? (3 mark)
- peer reviewed by other scientists
- scientific findings published
- idea presented at scientific conference
(- repeat experiments to validate results)
(- sharing on the media, internet)
What are the biochemical differences between domains?
Cell wall compositions
(e.g. peptidoglycan in bacteria)
What are the evidence for the three domains?
RNA sequence and sensitivity to antibiotics
What is the main limitation of biological species concept?
inapplicable to: (1) fossil species; (2) organisms reproducing asexually
How to classify organism groups of species? 3 steps
- Evolutionary relationships between organisms and their ancestors
- Classifying species into groups using their shared features derived from ancestors
- Arranging groups into a hierarchy
What is the definition of evolution?
Organisms with different genotypes lead to different phenotypes within a specific environment.
Advantage adaptations best suited to the environment will be passed onto the next generation (alleles)
What are sources of genetic variation?
Random fertilisation
Crossing over
Independent assortment
Mutations
How does natural selection give rise to adaptations?
Genetic variation between species due to mutations (and other reasons), selection pressure favours certain alleles. Those with beneficial alleles survive and reproduce, passing on beneficial alleles to offspring and over generations lead to adaptation.
What is the definition of niches? 2 marks
Role of an organism (1)
In its habitat / ecosystem (1)
Eg Where a species lives, what it eats, its predators, and how it interacts with non-living surroundings
What are 3 adaptations for developing a good niche?
Anatomical
Physiological
Behavioural
What are anatomical adaptations?
Adaptations involving actual structure and form of an organism
What are physiological adaptations?
Adaptations that involves how the organism works eg biochemical pathways, enzymes and metabolisms
What are behavioural adaptations?
Specific types of behaviour that make organisms better adapted to their surroundings and more likely to survive
What is allopatric speciation
When two populations (plants or animals) are totally separated from each other by a geographical barrier (eg river, mountain) , preventing interbreeding
Geographical isolation
What is the definition of speciation?
Process where one species may evolve from another often due to isolation
How does speciation happen?
Change of conditions, adaptations may not be advantageous
There is a different selection pressure
Natural selection continue and lead to formation of new species
What is the sympatric speciation? (2 marks)
- Formation of one new species
- while both still living in the same location
(mixing freely but become reproductively isolated)
(Due mechanical, ecological, behavioural or temporal isolation)
What are 4 things that lead to sympatric speciation?
- ecological isolation (eg half lives in water and on land)
- temporal (when 2 populations mate at different times of the year)
- mechanical isolation (physically can’t reproduce)
- behavioural (
what is the biggest group of pathogen?
bacteria
Who discovered the first antibiotic penicilin?
Alexander Flemming
What are Gram positive bacteria?
Thick peptidoglycan walls
stains purple with crystal violet
susceptible to antibiotics
PPP: Positive Purple Peptidoglycan
what are gram negative bacteria?
thin peptidoglycan wall with additional lipid layer
prevents staining
impermeable to antibiotics
How did bacteria gain resistance to antibiotics?
1% of bacteria mutate
most bacteria die under antibiotics except mutated ones, advantageous so keep producing
it multiplies via mitosis
eventually the whole population is resistant
What are issues with antibiotics?
- they are too widely prescribed
- ## people dont complete courses of antibiotics
How to tackle issues with antibiotics?
- reduce use
- better education
How do scientists classify species?
- ecological
- mate recognition
- evolutionary species
- genetic species
what are evidence for the 3 domains?
- different nucleotide and RNA sequence
- cell membrane lipid structure
- cells walls not of peptidoglycan
how can organisms be classified into taxonomic groups? 2 marks
- organisms share similar characteristics placed in a group
- molecular phylogeny
- dna profiling
How can scientists classify an organism as a new species? 4 mark
- compare physical characteristics
- observe behaviour
- molecular phylogeny (Use DNA sequencing / biochemistry)
- unable to breed with or their species and produce fertile offspring
Why is it difficult to classify a newly discovered organism as a separate species? 2 marks
- some species can interbreed and produce fertile offspring
- species are evolving overtime
- there is variation within the species
Why can flies develop resistance so quickly?
They have short life cycle
Flies produce lots of offspring
Explain the evidence that led to three-domain system, replacing five kingdom classification. 3 marks
- molecular phylogeny
- able to identify similarities and differences between bacteria and archaea
- eg membrane structure, proteins etc
Explain how evolution can occur through natural selection. (3 marks)
- genetic mutation / variation
- some organisms are better adapted to survive
- reproduce
- alleles passed on
Compare and contrast allopatric and sympatric speciation. (4 marks)
(write heading in exam)
Similarities:
- reproductive isolation
- one original population
- absence of gene flow
Difference:
Allo / Symp
- requires geographic isolation / does not
- does not / diff food and behaviour
Given that Tasmanian wolves are marsupial mammals and grey wolves are placental.
Explain why grey wolves and close relatives are found in many parts of the world, while Tasmanian wolves only survived in isolated islands. (3 marks)
- higher survival as a placental mammal
- since offspring are born more developed, while marsupials are born very small
- grey wolves outcompete Tasmanian wolves, TM can only survive where less competitors also inhabit
