Classification And Biodiversity Flashcards
Definition of phylogenetic
Reflecting evolutionary relatedness
Phylogenetic method
Grouping closely related organisms together- may show physical similarities.
Phylogenetic tree
- diagram showing evolutionary descent
- living organisms at tips of branches
- ancestral species in the branches and trunk
- branch points representing common ancestors
Definition of hierarchy
Smaller groups are components of larger ones
Definition of Taxon
Group with system of classification
What is meant by taxa are discrete?
An organism belongs in only one Taxon
What is the hierarchy of biological classification?
Domain Kingdom Phylum Class Order Family Genus Species
Reasons for classifying
- infer evolutionary relationships
- predict characteristics when a new animal is discovered
- easier to say
- more useful to count families than species when describing the health of an ecosystem or rate of extinction
What are the three domains?
- Eubacteria: prokaryotes ( e.coli and salmonella)
- Archaea: bacteria, unusual metabolism, live in marginal habitats, prokaryotes
- Eukaryota: plantae, animalia, fungi, protoctista
Definition of genus
A group of similar organisms
Definition of species
A group of organisms sharing a lot of physical features and able to interbreed to make fertile offspring
Definition of prokaryota
Microscopic
All bacteria and Cyanobacteria
Definition of protoctista
- some have one cell, major component of plankton
- some are colonial
- spirogyra- plant like cells
- amoeba- animal like cells
- euglena- characteristics of both plant and animal cells
- some have many similar cells- seaweeds or algae
Definition of plantae
- mosses, horsetails and ferns reproduce with spores
- conifers and flowering plant, which reproduce with seeds
Definition of fungi
Yeasts- single called
Mounds- hyphae weave together to form mycelium
Definition of animalia
35 animal phyla
Most are motile at some stage
Definition of homologous structure
Similar form and developmental origin but different functions.
Definition of divergent evolution
Common ancestral structure has evolved and performs different functions
Definition of convergent evolution
Structures evolve similar properties but have different developmental origins
Definition of analogous structure
Corresponding function and similar shape but different developmental origin
What are the 4 ways of assessing relatedness with genetic evidence?
- DNA sequences
- DNA hybridisation
- amino acid sequences
- immunology
Morphological definition of species
If two organisms look very similar they are likely to be in the same species
Sexual dimorphism must be taken into account- presence of manes in male lions but in females
Reproductive definition of species
Two organisms in the same species can interbreed to make fertile offspring
Dissimilar organisms may have different chromosomes no or incompatible physiological
Definition of binomial system
The system of giving organisms a unique name with two parts, the genus and species.
Definition of taxonomy
Identification and naming of organisms
What does taxonomy allow us to do?
- discover and describe biological diversity
- investigate evolutionary relationships
- classify organisms to reflect evolutionary relationships
Advantages of binomial system
- unambiguous naming
- used all over the world
- implies species sharing a name are closely related
Definition of biodiversity
The number of species and the number of each species in a specified region
Definition of biodiversity hotspots
Major areas of biodiversity
Around the equator and tropics
Impacts of reduced biodiversity
- plant species provide staple foods e.g. Wheat and rice
- medicinal drugs from plants and fungi
- living organism provide important raw materials e.g. Rubber cotton
- each species is unique
Definition of natural selection
The gradual process in which inherited characteristics become more or less common in a population, in response to the environmental determining the breeding success of the individuals possessing those characteristics
Definition of adaptation
The change in a species as a useful characteristic becomes more common
Examples of anatomical traits
Stream lined body
Honey guides indicate centre of flower
Examples of physiological traits
Polar bear- body temp drops to 2 degrees to use less energy
Leaves fall of trees so water is not lost in transpiration
Examples of behavioural traits
Plants flower in spring when pollinating insects have emerged
Mating rituals- peacocks
Definition of selection pressures
Environmental factors that affect an individual’s reproductive success
