Section 4 - Biodiversity Flashcards
What is a population?
Group of individuals of the same species that live in the same place and can interbreed.
How does the reproductive success of individuals affect allele frequency?
Random gene mutations lead to new alleles in a gene pool
New alleles allow individuals to survive and reproduce
Offspring inherit the new allele
Over generations new advantageous allele will increase
What is gene pool?
The variety of alleles in a population
What is directional selection?
Environmental favours individuals at one extreme of the bell curve
Individuals outside of mean will have phenotype for suited to new conditions
(Mean value changes)
What is stabilising selection?
If environmental conditions remain stable, individuals with phenotypes closet to mean are favoured.
Individuals more likely to pass alleles onto next generation.
Individuals with extreme phenotypes are less likely to survive
(Mean stays the same)
What is classification?
The grouping of organisms
What is taxonomy?
The theory and practice of biological classification
What is a species?
A group of organisms which have similar characteristics are able to breed to produce fertile offspring
What is the system for naming species?
The Binomial system
What two categories identifies organisms using the binomial system?
The generic name: genus (capital and underlined)
The specific name: species (underlined)
What is courtship behaviour?
A necessary precursor to successful mating
What factors are included in courtship behaviour?
Species recognition
Attracting a mate that’s capable of breeding
Pair bond formation
Synchronisation of mating
What are the advantages of courtship behaviour?
Individuals can:
- recognise sexually mature members of their species of the opposite sex
- synchronise mating
- form a pair bond
- successfully breed
What are the 8 groups in the classification hierarchy?
largest to smaller
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is artificial classification?
Divides organisms according to differences that are useful at the time
(colour, size, number of legs, leaf shape)
What is phylogenetic classification?
- Based upon evolutionary relationships
- Classifies species into groups with shard features derived from ancestors
- Arranges groups into hierarchy
What are the 3 domain types?
Bacteria
Archaea
Eukarya
What is the domain, bacteria?
Single-celled prokaryotes
- Absence of membrane-bound organelles
- Unicellular
- Ribosomes are smaller (70s) than eukaryotes
- Cell walls are present (murein)
- Single loop of naked DNA
What is the domain, archaea?
Single-celled prokaryotes
- Genes and protein synthesis
- Membranes contain fatty acid chains attached to glycerol by ester linkages
What is the domain, eukarya?
Organisms made up of one or more eukaryotic cell
-Cell possess membrane-bound organelles
-Membranes containing fatty acid chains attached to glycerol by ester linkages
Ribosomes are larger (80s)
What is phylogeny?
The evolutionary relationship between organisms
In a phylogenetic diagram what is at base of the tree?
The oldest species
What are one thing that all members of a species have?
They are capable of breeding to produce offspring which are themselves fertile
What are 3 features of a phylogenetic system of classification?
Based on evolutionary relationships between organisms and their ancestors
Classifies species into groups using shared characteristics from their ancestors
Arranged in a hierarchy with no overlap
Why is it important for species recognition in courtship?
Ensures mating only takes place between members of the same species as only they can produce fertile offspring