✅10 - Biodiversity Flashcards
What is a species?
Organisms capable of breeding to produce living, fertile offspring
Which system is used to name species?
The binomial system
What is the first name in the binomial system?
Th generic name - denotes the genus
What is the second name in the binomial system?
The specific name - denotes the species
How are names of species written?
Typed in italics or handwritten and underlined
What are the purposes of courtship behaviour?
To recognise members of their own species
Identify a mate that is capable of breeding
To form a pair bond
To synchronise mating
To become able to breed
Why is it necessary to recognise members of their own species?
To ensure that mating only takes place between members of the same species to ensure fertile offspring
Why is it necessary to identify a mate that is capable of breeding?
Because both partners need to be sexually mature, fertile and receptive to mating
Why is it necessary to form a pair bond?
To lead to successful mating and raising of offspring
Why is it necessary to synchronise mating?
So that it takes place when there is a maximum probability of the sperm and egg meeting
Why is it necessary to become able to breed?
Because a member of the opposite sex needs to be in a physiological state that allows breeding to occur
How do animals tell if a partner is of the same species?
Courtship behaviours are unique to each species
What is classification?
The grouping of organisms
What is taxonomy?
The theory and practise of biological classification
What is artificial classification?
Divides organisms according to differences that are useful at the time, eg size, colour, leaf shape etc. Described as analogous characteristics where they have the same function but not the same evolutionary origin
What is phylogenetic classification?
Based upon the evolutionary relationships between organisms and their ancestors, species classified into groups based on shared features derived from ancestors
What are the 3 domains?
Bacteria, Archaea, Eukarya
What is a mnemonic for remembering the order of taxonomic ranks?
Delicious King Prawn Curry Or Fat Greasy Sausages
What are the taxonomic ranks?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What are the features of the Bacteria domain?
No membrane bound organelles Unicellular Small ribosomes (70s) Cell walls made of murein Single loop of DNA, no histones
What are the features of the Archaea domain?
Genes and protein synthesis similar to eukaryotes
Membranes contain fatty acid chains attached to glycerol by ether links
No murein in cell walls
More complex form of RNA polymerase
What are the features of the Eukarya domain?
Membrane bound organelles
Membranes contain fatty acid chains attached to glycerol by ester links
Not all possess cell walls, but if they do there is no murein
Ribosomes are larger (80s)
What are the four kingdoms in the Eukarya domain?
Protoctista, Fungi, Plantae and Animalia
How do organisms differ between phyla?
They have different body plans
What is phylogeny?
The hierarchical order of taxonomic ranks based upon the supposed evolutionary line of descent of the group members
What is species diversity?
The number of different species and the number of individuals of each species in a community
What is genetic diversity?
The variety of genes possessed by the individuals that make up a population of species
What is ecosystem diversity?
The range of different habitats from a small local habitat tot he whole Earth
What is species richness?
The number of different species in a particular area at a given time
What is the formula for the index of diversity?
d = N(N-1) / Σn(n-1)
What major impact does agriculture have on biodiversity?
Reduced genetic variation and species richness
How does farming reduce genetic variation?
Farmers generally choose species for specific qualities that make them more productive, so the number of species and the genetic variety of alleles decreases
How does farming reduce species
Generally, only one species is grown in order to obtain high yield of that species
How else can habitats be impacted by agriculture?
Use of pesticides
Low index of diversity
What farming practices have directly removed habitats?
Removal of hedgerows, creating monocultures, filling in ponds and draining mashlands, over-grazing of land
What farming practices have indirectly removed habitats?
Use of pesticides, escape of effluent, absence of crop rotation and lack of intercropping
What conservation techniques are used by farmers?
Maintain existing hedgerows Plant hedges rather than use fences Maintain existing ponds Plant native trees on areas of land with low species diversity Use organic fertilisers
Why does using observable characteristics to classify organisms have limitations?
Because a large number of characteristics are coded for by more than one gene - polygenic, or can be modified by the environment
What methods are used to investigate diversity?
Comparison of DNA base sequences
Comparison of the base sequence of mRNA
Comparison of amino acids sequences in proteins
How are DNA base sequences compared?
Automatic machines can sequence DNA and different nucleotides can be tagged with different colours to make them comparable between seqeunces
What can be identified from comparison of DNA base sequences?
Mutations
How can the amino acid sequence of proteins be compared?
The degree of similarity between sequences from different species reflects how closely related the species are
What is interspecific variation?
When one species differs from another
What is intraspecific variation?
When members of the same species differ from one another
What is random sampling?
Sampling with the least possible bias, by eliminating human involvement in choosing samples
How can the effect of chance in a sample be minimised?
Use a large sample size
Analyse the data collected
