Classification Flashcards
Taxonomy
The science of describing, classifying and naming living organisms. Kindom, Phylum, Class, Order, Family, Genus, Species
The binomial system
- Use italics
- Genus name (upper-case) species name (lower-case)
- After first use, names are abreviated to initial of genus and then the species name (H. sapiens)
What is a species? (models and concepts)
- Morphological species concept (appearance)
- Ecological species model (ecological niche)
- Mate-recognition species model (mating behaviours)
- Genetic species model (DNA evidence)
- Evolutionary species model (shared evolutionary relationships)
Identifying individual species
DNA profilling
DNA sequencing (determines the exact order of nucleotides A, T, C, G)
Gel electrophoresis (amino acids)
- may be positive or negative charged so sample placed at centre
- dye isnt added
- Ninhydrin is added after which turns purple
- these can then be paired to known amino acids
Theory of evolution
- living organisms that reproduce sexually show great variety in their appearance
- organisms produce an excess of offspring
- organisms that inherit good characteristics are most likely to survive and reproduce
- organisms that inherit bad characteristics are most likely to die
Successful adaptions
Anatomical (form and structure)
Physiological (the way the body works)
Behavioural (changes making better adaptions)
Race between pathogens and medicines
Beating bacteria step 1 = Fleming + Florey + Chain discovered penicillin but it only had an affect on gram positive bacteria.
Bacteria fight back = anti biotic resistant bacteria. Penicillinase enzyme split penicillin so it no longer works.
Beating bacteria step 2 = methicillin was produced, resistant bacteria spread rapidly, now it has few uses.
Isolating mechanisms
Geographical iso (physical barrier such as river)
Ecological iso (inhabiting same region but different parts)
Seasonal iso (sexual receptiveness drifts away)
Behavioural iso (changes in courtship rituals)
Mechanical iso (mutation changes the genetalia of animals)
Allopatric speciation
Popualtions are physically/geographically seperated in some way.
Sympatric speciation
Living in the same place that become reproductively isolated.
