Biology: Topic 4 Flashcards
Biodiversity
The variety of organisms within an ecosystem.
Species
A group of organisms that can interbreed to produce fertile offspring. They will have similar morphology, physiology and behaviour.
Habitat
Where an organism lives. Different habitats have specific conditions.
Population
A group of interbreeding organisms of the same species in the same area.
Community
The combination of all the various populations within a habitat.
Niche
The way an organism exploits it’s environment. Food source, shelter, time of feeding, etc.
Adaptation
A feature that helps an organism survive in it’s environment and exploit their specific niche. Can be behavioural, physiological or anatomical.
Adaptation: Behavioural
Behavioural adaptations of organisms are any action that is carried out by an organism.
Adaptation: Physiological
Physiological adaptations involve the internal mechanisms of an organism.
Adaptation: Anatomical
Anatomical adaptations are the physical structures of an organism.
Co-adaptation
When species adapt at the same time to become dependant on one another.
Evolution by Natural selection
Organisms better adapted to survive selection pressures will reproduce and pass on their genes, whereas other organisms will die.
Selection pressure
Factors that require a population to adapt in order to survive.
Conditions required for evolution by natural selection
Genetic variation within the population
Selection pressures
Reproduction must be occuring
Gene pool
Contains all the alleles of all the genes present in a population.
Reproductive isolation
Reproductive isolation can occur by the formation of a gene pool barrier, which can occur by geographical, temporal, behavioural or mechanical isolation.
Geographical isolation
Geographical isolation occurs when some organisms of the population become separated geographically.
Temporal isolation
Temporal isolation involves some organisms of the species reproducing at different times.
Behavioural isolation
Behavioural isolation means that the behaviours of some organisms in the population do not attract other organisms.
Mechanical isolation
Mechanical isolation is when some individuals evolve to be different shapes and sizes .
Speciation
When adaptations to some organisms in a population cause them to be unable to reproduce and produce fertile offspring with the non adapted organisms. Thus they have become a new species.
Hierarchy of classification
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
Scientific name for an organism
First the name of it’s genus, then the name of it’s species.
Phylogenetic tree
Phylogenetic trees can be used to show evolutionary relationships between different organisms. They show how each organism has adapted and can show which species have common ancestors.
