Biodiversity Flashcards
(34 cards)
Define species
Organisms that are capable of breeding in order to produce fertile offspring
Describe the principle of binomial names
The first name is the generic name- denotes the genus to which the organism belongs
The second name is the specific name which denotes the species to which an organism belongs
Describe the importance of courtship behaviour
- Recognise members of their own species, to ensure mating only happens between individuals of the same species so fertile offspring is produced
-Identify a mate that is capable of breeding, both members need to be sexually mature, fertile and receptive to mating - Form a pair bond which will lead to sucessful mating and raising of offspring
- Syncronise mating so it takes place when there is a high probability of sperm and egg meeting
Describe the importance of courtship behaviour during the female receptive stage
- Females of many species have a short period of time where they can conceive
- This means they are receptive to mating as they are producing eggs
-Courtship is used by males to determine if the female is in the receptive stage, if she responds with the appropriate behavioural response, courtship continues and is likely to result in the production of fertile off spring
Describe the principle of artificial classification
- Divides organisms according to differences which are useful at the time, such features may include colour, size, number of legs etc
-These are analogous characteristics where they have the same function but not the same evolutionary origins
Describe the principle of phylogenetic classification
- This is based upon the evolutionary relationships between organisms and their ancestors
-Classifies species into groups using shared features derived from their ancestors - Arranges the groups into a hierarchy in whichs groups are contained within larger composite groups with no overlap
What is a taxon
-Each group in a phylogenic biological classification
Describe the features of the bacteria domain
-Group of single celled prokaryotes
- Have an absence of membrane bound organelles such as mitochondira
-Unicellular, although they may occur in clusters
-Ribsomes are smaller (70s)
-Cell walls are present and always made of muerin and never chitin
-Single loop of naked DNA made up of nucleic acids but never histones
Describe features of the archea domain
-Group of single celled prokaryotes which resemble bacteria, however they differ from bacteria because
-Their genes and protein synthesis are more similar to eukaryotes
-Their membranes contain fatty acid chains attached to glycerol by ether linkages
- No muerin in their cell walls
- Have more of a complex form of RNA polymerase
Describe the features of the Eukarya domain
- Their cells posses membrane bound organelles such as mitochondria and chlorplasts
-They have membranes containing fatty acid chains connected to glycerol by ester linkages - Not all possess cells with a cell wall, but when they do it contains no meurin
-Ribosomes are larger ( 80s) than in bacteria and archea
Describe the classification sequence
-Kingdom
-Phylum
-Class
- Order
-Family
-Genus
-Species
Name the 3 components of biodiversity
Species diversity
Genetic diversity
Ecosystem diversity
Define species diversity
The number of different species and the number of individuals of each species in any one community
Define genetic diversity
Refers to the variety of genes possessed by individuals that make up a species
Define ecosystem diversity
Refers to the range of different habitats from a small local habitat to the whole of the earth
Describe the principle of species richness
Number of different species in a community
Two communitys may have the same species richness but may have different proportions of each species in the community
Give the equation used for measuring species diversity ( index of diversity)
d= N(N-1) divided by the sum of n(n-1)
The higher the value of D the greater the species diversity
How do farming techniques( agriculture) have impacts on biodiversity
Farmers select species for particular qualities that make them more productive, this means the species richness and the genetic variety of alleles they possess is reduced to the few which exhibit the desired features, in order to be economic the number of individuals with the desired feature has to be high
This means a lower area of farming ground is provided for other species without the desired quaility, meaning individuals in this area have to compete for resources such as food and water, most dont survive this due to pesticides being used so no resources are being competed for, and not enough resoruces to live
This means the index of species diversity is considerably low in agricultural ecosystems
Describe how the economical need for mass food production is prioritised over conservation
-The overriding effect of intense food production has been to diminish the variety of habitats within the ecosystem, therefore reducing species diversity
E.g- removal of hedgerows and grubbing out woodland
Creating monocultures
Filling in ponds and draining wetlands
Over grazing of land, upland areas by sheep, preventing regeneration of woodland
Describe indirect practices farmers do to keep farming economical which reduce species diversity
-Use of pesticides and inorganic fertilisers
-Escape of effluent from silage stores and slurry tanks into water courses
- Absence of crop rotation and lack of intercropping or undersowing
Describe the management techniques used by farmers between the intense need of food production and the reduction of species diversity
-Maintain existing hedgerows at the most beneficial height and shape, A shape is preferable
- Plant hedges rather than erect fences at field boundaries
- Maintain existing ponds and where possible create new ones
-Leave wet corners of fields rather than draining them
-Use organic instead of inorganic fertilisers
-Use a crop rotation which uses nitrogen fixing crop rather than fertilisers to improve soil fertility
How can genetic diversity be investigated between species or within a species by comparing observable characteristics?
Genetic diversity can be measured using observable characteristics of organisms based on the idea that each observable characteristic is determined by a gene or genes
- The variety within a characteristic depends upon the number and variety of alleles for each gene ( and environmental influences)
Describe limitations of comparing observable characteristics in order to measure genetic diversity between different species or within a species
- A large number of them are coded by one or more genes, they are polygenic
- Means they are not discrete from each-other but they vary continuously, hard to distinguish one from another
-Characteristics can also be modified by the environment meaning differences in characteristics can be caused by the environment not genetc
How is comparison of base sequences used to measure genetic diversity within or between different species
- DNA sequencing is now done by automatic machines which shows the exact order of nucleotides and the data produced analysed by computers, each nucleotide is represented by a diff colour
- This produces a series of coloured bands
- This measures genetic diversity by sampling DNA of its members and sequencing it to produce a pattern of coloured bands
- Analysis of these patterns allows us to compare one species with another individual of the same species to show how diverse they are
We expect species more closely related to have more similar genetics and base sequences
