Species and Taxonomy Flashcards
(23 cards)
Species:
Organisms are capable of breeding to produce living, fertile offspring.
Binomial system:
first name - genus (first letter of the work upper case) and second name - species
Courtship behaviour
Individuals can, therefore, recognise members of their own species by the way they act. The ability to display a behaviour is genetically determined
What is the purpose of courtship behaviour?
- Recognise members of their own species, identify a mate that is capable of breeding, form a pair bond, become able to breed, synchronise mating.
What is artificial classification?
Divides organisms according to differences that are useful at the time. Some features may include colour, size and number of legs.
What is phylogenetic classification?
Based upon the evolutionary relationship between organisms and their ancestry, species are grouped using shared features derived from their ancestors
What is phylogenetic classification partly based on?
Homologous characteristics have similar evolutionary origins regardless of their functions in the adult of a species
What is a taxon?
Each group within a phylogenetic biological classification
What is Taxonomy?
The study of these taxons and their positions in a hierarchical order, and these are known as taxonomic ranks
What are 3 domains?
Bacteria, Archaea (a group of prokaryotes) and Eukarya
What is the bacteria domain?
A group of single-celled prokaryotes.
What are the Archaea?
A group of single-celled prokaryotes that were originally classified as bacteria, which they resemble in appearance.
How does Archaea differ from bacteria?
There is no meurin in cell walls, their genes and protein synthesis more similar to euakryotes, they have more complex form of RNA polymerase
What is a Genetic Bottleneck?
A genetic bottleneck is an event that drastically reduces the size of a population, leading to a loss of genetic diversity.
What causes genetic bottle neck?
A genetic bottleneck usually occurs after:
A natural disaster (e.g. earthquake, flood, volcanic eruption)
Disease outbreaks
Human activity (e.g. overhunting, habitat destruction)
Why is genetic bottleneck a problem?
Only carries a small fraction of the original gene pool (i.e., fewer alleles)
So, there’s less genetic variation in future generation
What is genetic diversity?
Number of different alleles of genes in a population
What are alleles and how do they arise?
● Variations of a particular gene (same locus) → different DNA base sequence
● Arise by mutation
What is a population?
● A group of organisms of the same species in a particular space at a particular time
● That can (potentially) interbreed (to produce fertile offspring)
Explain the importance of genetic diversity
● Enables natural selection to occur
● In certain environments, a new allele of a gene might benefit its possessor
● By resulting in a change in the polypeptide (protein) coded for that positively changes its properties
● Giving possessor a selective advantage (increased chances of survival and reproductive success)
What is evolution?
● Change in allele frequency (how common an allele is) over many generations in a population
● Occurring through the process of natural selection
Explain the principles of natural selection in the evolution of populations
- Mutation - Random gene mutations can result in [named] new alleles of a gene
- Advantage - In certain [named] environments, the new allele might benefit its possessor [explain why] → organism has a selective advantage
- Reproduction - Possessors are more likely to survive and have increased reproductive success
- Inheritance - Advantageous allele is inherited by members of the next generation (offspring)
- Allele frequency - Over many generations, [named] allele increases in frequency in the population
Describe 3 types of adaptations
Natural selection results in species that are better adapted to their environment:
● Anatomical - structural / physical features that increase chance of survival
● Physiological - processes / chemical reactions that increase chance of survival
● Behavioural - ways in which an organism acts that increase chance of survival