Year 12 Biology - UNIT 3 TOPIC 1. Classification Processes Flashcards
LInnaean System
Classification system created by ‘Carl Linnaeus’ in the 1750s. Focuses on the similarity of physical features into taxons or hierarchical levels (domain, kingdom, phylum, class, order, family, genus, species)
Kingdom
The second highest taxon in Linnaean classification; includes Animalia, Plantae, Protista, Fungi, Archaea, Bacteria
Phylum
The third highest taxon in Linnean classification
Prokaryote
‘Prokaryotes’ do not contain membrane-bound organelles, the nucleus is also absent. They are unicellular (Bacteria & Archaea). They are typically smaller in size in comparison to eukaryotes and they multiply through binary fission. Because Prokaryotic DNA interacts with cytoplasm, transcription and translation occur simultaneously.
Classification Systems
All are hierarchical and based on different levels of similarity.
1. Linnaean system - similarity of physical features
2. Methods of reproduction - asexual or sexual (eutherian, marsupial, monotreme)
3. r/K selection - mathematical classification based on the number of offspring and parental care
4. Molecular phylogeny/cladistics - similarity of molecular sequences
Classification Systems
All are hierarchical and based on different levels of similarity.
1. Linnaean system - similarity of physical features
2. Methods of reproduction - asexual or sexual (eutherian, marsupial, monotreme)
3. r/K selection - mathematical classification based on the number of offspring and parental care
4. Molecular phylogeny/cladistics - similarity of molecular sequences
Domain
The highest ranking taxon in Linnaean classification; includes Eukarya, Archaea, Bacteria
Eukaryote
‘Eukaryotes’ are cells that have a nucleus (membrane-bound) and other Membrane-bound organelles (aside from nucleus). These cells can either be unicellular (Fungi & Protis) or multicellular (Plant & Animal cells). Eukaryotes are typically larger in size in comparison to prokaryotes. In these cells, transcription occurs within the cell and translation within the cytoplasm. They multiply through mitosis and meiosis.
Clade
A group of organisms that consist of a common ancestor and all its lineal descendants
r/K Selection
A form of mathematical classification based on the number of offspring a species produces and the level of parental involvement required to care for them
Division
The third highest taxon in LInnaean classification (eg- Tracheophyta/ vascular plants)
Order
The fifth highest taxon in Linnaen classification (eg-Carnivora)
Hierarchy
A system categorised by the specific arrangement of information into layers
Cladistics (molecular phylogeny)
A taxonomic technique that arranges organisms by clade or descendants of particular ancestor organisms.
Class
The fourth highest taxon in Linnean classification (eg- Mammalia)
Taxonomy
A system of classification, particularly biological; the study of systems of classificarion
Taxon
A level of hierarchical classification system (Eg- Kingdon, Family, Species)
Methods of reproduction
Type of classification - asexual or sexual. Class Mammalia is split into three main based on where offspring develop
1. Eutherian - Offspring develop completely in the mother with an attached placenta and has a live birth
2. Marsupial - fetus brighter at a very early developmental stage and complete development in the pouch
3. Monotreme - offspring develop in eggs
Family
The sixth highest taxon in Linnaean classification (Eg- Felidae)
Species
The lowest taxon in Linnaean classification; it is always italicised and combined with genus (eg- Felis catus)
Bifurcaction
The division of something into two branches or parts
Binomial Nomenclature
A naming system in which each individual is given a two-part name, such as genus and species or first name and surname
Genus
The seventh highest taxon in Linnaean classification; it is always italicised (Eg- Felis)
Common Ancestor
A species of organism whose offspring diverges over time
Assumptions of Cladistics
Assumptions include:
- common ancestry
- bifurcation
- physical change
Plesiomorphic
Having characteristics or traits that are common among their evolutionary relatives, but are not unique to their clade (Eg- members of class Reptilia usually have legs as do many organisms no in class Reptilia)
Node
A point in a diagram where lines branch or intersect
Molecular Homology
The identification of shared biomolecular elements - generally genes; used to test the relationships between organisms, which can demonstrate common ancestory
Cladograms
Phylogenic tree diagrams that show the most probable sequence of divergence in clades; grouped according to their most likely evolutionary relationships
Apomorphic
Having characteristics or traits unique to a particular group of organisms that are different from their evolutionary relatives (Eg- snakes, in class Reptilia, have no legs)
Conserved Sequence
DNA or protein that is preserved across species due to optimal function.
Question: Why are multiple definitions of species needed?
- Biological species concept - the capacity to interbreed by two individuals; speciation occurs when breeding cannot occur naturally.
- Hybrid organisms exists - interbreeding of teo species (Eg- donkey + zebra +zonkey); difficult to classify because they are bred from two species.
- Morphological species concept - based on physical characteristics - Fossilis: impossible. with extinct organisms; we don’t know if they could interbreed or if physical differences mean a new species or just a variation in species
- Ohylogenic species concept - based on common ancestor; relies on cladistics which is limited to scientists understanding of the genetics of organisms.
Question: Explain how molecular sequences are used to infer species evolutionary relatedness
- protein conservation
- molecular sequencing
- histones
- dating divergence
- mutations
Questions: Explain how ecosystems are composed of varied habitats (microhabitat to ecoregion)
- rainforest canopies
- vertical stratification
Describe the process of stratified sampling in terms of:
- purpose
- site selections
- surveying technique
- bias
- methods of data presentation and analysis
- Purpose - estimating population, density, distribution, environmental gradients and profiles, zonation, stratification
- Site selections
- choice of ecological surveying technique - quadrant, transects
- minimising bias - size and number of samples, random-number generators, counting criteria, calibrating equipment and noting associated precision
- Methods of data presentation and analysis
Question: Explain an example of an interspecific hybrid that does not produce fertile offspring
Mules, bananas, grolars
Question: Explain the classification of organisms according to the following species interactions: predation, competition, symbiosis and disease
- Predation: 1 species kills and teats the other
- Competition: 2 or more individuals (whether the same species or not) compete for the same resources in the same area
- Symbiosis: a relationship between individuals or 2 or more species in which at least one organism benefits from the interaction: no death, just sickness; parasitism
- Disease: where a pathogen damages or kills a host
1/Question: Explain how the process of classifying ecosystems in an important step towards effective ecosystem management (consider old-growth forests, productive soils and coral reefs)
- allows decision-making about ecosystem, Can understand diversity
- consider different stakeholders
- management techniques
help reduce human impacts leading to long-term resilience
