Topic 3 Flashcards
(19 cards)
What is the correct taxonomic hierarchy in order?
Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species
What are the three domains of life?
Bacteria, Archaea, Eukaryota
What is molecular phylogeny?
A method of classification using molecular differences in DNA and proteins to determine evolutionary relationships.
How does gel electrophoresis work?
DNA is cut with restriction enzymes and placed in a gel. An electric current is applied; negatively charged DNA moves towards the anode. UV light shows DNA bands for comparison.
Define a species (biological definition).
A group of organisms that can interbreed to produce fertile offspring.
What are the limitations of the biological species concept?
Some species interbreed with others (hybrids); some members of the same species don’t interbreed; doesn’t apply to extinct or asexual organisms.
What are alternative models of defining species?
Ecological, mate-recognition, genetic, and evolutionary models
What is species richness?
The number of different species in a habitat.
What is genetic diversity?
The variation of alleles within a species’ gene pool.
What formula is used to calculate the Index of Diversity (D)?
D = N(N-1) / Σn(n-1), where N = total organisms, n = number per species
What is in situ conservation?
Conserving species in their natural habitat (e.g., national parks, SSSIs)
What is ex situ conservation?
Conserving species outside their natural habitat (e.g., zoos, seed banks)
Why are seed banks useful for conservation?
Store genetic diversity cheaply; take up less space than full plants; seeds stored in cool, dry conditions and tested for viability
What are the 3 types of adaptation?
Anatomical, Behavioural, Physiological
Give an example of each adaptation type.
Anatomical: Long loop of Henlé in desert mammals; Behavioural: Migration, feigning death; Physiological: Hormonal control of blood flow
What is natural selection?
Process where advantageous alleles become more common in a population over generations due to survival and reproduction advantages.
What is speciation?
Formation of new species through reproductive isolation and accumulation of genetic differences.
What are the two main types of speciation?
Allopatric: Geographic isolation; Sympatric: Behavioural, temporal, gametic isolation
How does antibiotic resistance evolve in bacteria?
Mutations produce resistance → antibiotics kill non-resistant → resistant bacteria survive, reproduce and spread the resistant allele → population becomes resistant.
