Unit 2 (2.1) Flashcards
Biodiversity and classification
Classification definition
Classification is the division of living organisms into groups based on their evolutionary relationships.
Species definition
A group of similar organisms that can interbreed to produce fertile offspring
Can the classification of an organism change?
Yes, as new information becomes available
Seven groups in hierarchy
Kingdom
Phylum
Class
Order
Genus
Species
Five kingdom classification system
Animal
Fungi
Plantae
Prokaryote
Protoctista
Three domain classification system
Archaea
Bacteria
Eukarya
What do organisms in the same domain have in common?
Organisms in the same domain share a distinctive pattern of ribosomal RNA
Animalia characteristics
Multicellular eukaryotes
No cell wall
Heterotrophic
Nervous coordination
Prokaryotae characteristics
Lack of nucleus
Lack of membrane bound organelles
70s ribosomes
Circular DNA
Peptidoglycan cell wall
Protoctista characteristics
Mostly unicellular eukaryotes
Algae have no tissue differentiation
Plantae characteristics
Multicellular eukaryotes
Photosynthetic containing chloroplasts
Cellulose cell wall
Fungi characteristics
Heterotrophic eukaryotes
Cell wall made of chitin
Most composed of thin threads of hyphae
Reproduce by spores
How to find out the relatedness of organism
Physical features
Biochemical methods
Physical features and biochemical methods
DNA ‘genetic fingerprinting’
Enzyme studies
What is DNA profiling
Method of determining the characteristics of an individuals DNA
Percentage of DNA or proteins shared between species is used to estimate relatedness
Use of binomial system in naming system
In the binomial system of classification, each organism is named for its genus then its species.
Advantage of binomial system
Biochemical methods reduce mistakes made from observing physical features alone.
It’s universal
What are the two components to a binomial
Generic name (genus) must be capitalised
Specific name (species)
What is a homologous feature?
Homologous features have evolved from the same structure for different functions. They indicate a common ancestor
What is a Analogous feature?
Analogous features are structures that have evolved independently for the same function.
Homologous feature example
Pentadactyl limb found in mammals, birds and reptiles
Analogous feature example
The wings of birds and insects
What is biodiversity?
The number and variety of living organisms in a given region. It is affected by environmental, genetic and human factors.
What factors can biodiversity be affected by?
Environmental factors
Genetic factors
Human factors
How can biodiversity in a habitat be assessed?
Using Simpson’s Diversity index
What is Simpson’s Diversity index?
A measurement of diversity that considers both species richness and evenness
A value between 0 and 1 is found
The closer the value is to 1, the greater the biodiversity
How can biodiversity can be assessed within a species at a genetic level?
By looking at the variety of alleles in the gene pool of a population, e.g. the proportion of polymorphic loci across the genome.
How can we calculate genetic diversity within a species?
Proportion of polymorphic gene loci=
Number of polymorphic gene loci
——————————-
Total number of loci
What is polymorphism?
The presence of different phenotypes among members of a single species
How can biodiversity be assessed at a molecular level?
Determining the entire DNA nucleotide base sequence of an organism
How is DNA sequencing used to measure biodiversity?
Comparisons between members of the same species can identify variation in base sequences and hence estimate genetic diversity.
How has biodiversity been generated?
Through natural selection
What is an adaptation?
A feature of an organism that increases its chance of survival in it’s environment
What are the three types of adaptation?
Anatomical- Changes to physical features
Physiological- Changes to bodily processes
Behavioural- Changes to actions
