biodiversity and classification Flashcards
classification
putting items into groups
Phylogenetic
reflecting eveloutionary relatedness
Taxonomy
this is the study of the systems and
principles of classification, how we decide to group.
five kingdoms
animals, plants,
fungi, prokaryotes and protoctists.
further classification
phylum, class,
order, family, genus and species
hierarchy
system of ranking in which the small groups are nested components of larger groups
photolegentic tree
Diagram showing descent,with living in organisms at the tips of the branches and ancestral species in the branches and trunk with branch points representing common ancestors. Length of branches indicate time between bench points
Hierarchy of biological classcification
Domain> Kingdom> Phylum> Class> Order> Family> Genus> Species
Moving down the hierarchy, organisms in a taxon are more closely related
Moving up the hierarchy the members of a taxon are less closely related
Why we need a classification system
- Phylogenetic classification system allows us to interfere evelutionary relationships
- If a new animal is discovered with a beak or feathers we predict some of its other characteristics based on general understanding
- Quicker in communication to say certain words eg. Birds
- When describing the health of an ecosystem or rates of extinction in the geological record, conservationists often find it more useful to count families and species
Eubacteria
Prokaryotes like E coli and salmonella
Archaea
Bacteria with often unusual metabolism. Many are extremophiles eh. Organisms that live in extreme conditions
Eukaryota
Plantae, Animalia, Fungi and Protocista
Phylum
Subdivision of a kingdom based on general body plan
Domain
Highest taxon in biological classification: one of the three major groups into which live in organisms are classified
eg. eurkarota, archea, eubacteria
Kingdoms
All living organisms are classified into five kingdoms depending on physical features
Genus
Taxon containing organisms with many similarities but enough differences that they are not able to interbreed to produce fertile offspring
Species
A group of organisms that can enter breed to produce fertile offspring
Prokaryota
Microscopic - kingdom contains all bacteria, Archaea and cyanobacteria
Single celled
No nucleus
Mesosome in some, photosynthetic lamellae in some
70s
Peptidoglycan cell wall
Sapatrophic parasitic or autotrophic
protocista
Some only have one cell like plankton and others are colonial
Some have similar cells like seaweeds or algae
Single celled or multicellular
Nucleus and mitochondria, Some chloroplast
80s
Some cellulose, some no cell wall
Some autotrophic some heterotrophic
Plantae
Mosses, horse tales and fans reproduce with Spores
Conifers and flowering plants reproduce with seeds
Multicellular
Nucleus, mitochondria, chloroplast, vacuole, cell wall, autotrophic
80s
Fungi
Yeasts are single celled
moulds like penicillin and mushrooms have Hyphae that weave together to form the body of a fungus
In some fungi, cross cell walls- septa- subdivide the hyphae
Single celled or Hyphal
Nucleus, mitochondria, no chloroplasts, ER, chitin cell wall
saphtropic or parasitic
80s
‘
Animalia
Multicellular
Nucleus, mitochondria, no chloroplasts, ER, small temporary vacuole, no cell wall
80s
heterotrophic
Relatednass of organisms
Theory of evolution suggests that widely separated groups of organisms share a common ancestor
The more similar to organisms are the more recently they are assumed to have diverged
Homologous structures
Structures in different species with a similar anatomical position and development origin, derived from a common ancestor
Divergent evolution
The development of a different structures over long periods of Time, from the equivalent structures and related organisms
Convergent evolution
The development of similar features in unrelated organisms over long periid of time related to the natural selection of similar features in common environment
Analogous structures
Have a corresponding function and similar shape but have a different development origin
Assassin relatedness with genetic evidence - DNA sequencing
During the course of evolution, species undergo changes in their D N a base sequences which accumulate until the organisms are so different that they are considered to be different species. More closely related species show more similarity in their D N A base sequences than those more distantly related
DNA analysis has conferred evolutionary relationships and corrected mistakes made in classification based on physical characteristics
DNA hypridsation
Involves comparing DNA base sequences of 2 species. d N A is both extracted and separated into single strands and cut into fragments. Fragments are mixed and where they have complementary basics they hybridise together
Amino acid sequences
Sequence of amino acids and proteins is determined by DNA base sequence
The degree of similarity in the amino acid sequence of same protein in two species will reflect how closely related they are
Immunology
The proteins of different species can be compared using immunological techniques - if you mix antigens of one species with specific antibodies of another they will coagulate
The closer the evolutionary relationship the more coagulation occurs
Morphological definition
If two organisms look very similar they are likely to be in the same species there maybe differences
This sexual dysmorphism must be taken into account when deciding if two organisms are the same species
Reproductive definition
Another way of defining a species state that two organisms are in the same species if they can interbreed to make fatal offspring
Dissimilar organisms may have a different number of chromosomes or incompatible physiology or biochemistry so hybrid won’t be viable
Binomial system
System of giving organisms a unique name with two parts genus and species
Advantages of the binomial system
- Unambiguous naming
- Based on Latin- Scholarly language and used all over the world
- Implies that two species sharing parts of their name are closely related
Biodiversity
Number of species and number of individuals in each species in a specified region
Spatial variation
Number of species and number of organisms depend on the environment
- more plants grow at highlight intensity than at low light intensity so bright environment can support more herbivores and more carnivores than a dull one
- More energy flowing through an ecosystem produces more species and more individuals meaning equatorial regions have a much higher biodiversity than polar
Reasons to changes in biodiversity- succession
Overtime a community of organisms changes its habitats making it more suitable for other species. Change in the composition of community overtime it’s called succession
Increases animal biodiversity but decreases plant bidiversity
Polymorphism
The occurrence of more than one phenotype in a population with the rarer phenotype of frequencies greater than can be accounted for by mutation alone
Number of animals- assessment of biodiversity with polymorphic loci
A gene’s position on a chromosome is its locus. Lucas shows polymorphism if it has two or more alleles. If a gene has more alleles its locus is more polymorphic than if there was few alleles
In some plants:
- Gend T controls height. two different alleles
- Gene S Controls whether or not pollen congeminate on the stigma of a flower of the same species.
- S has a greater biodiversity than tea has more phenotypes are possible for S than T
Proportion of alleles
if most of the allioles of a particular gene are the same recessive allele there is low biodiversity for that gene
But if 50% were recessive and 50% other alleles, Biodiversity for that gene would be higher
Molecular assessment of biodiversity - DNA fingerprinting
organisms amorphously related to each other have DNA base sequences that are more similar
DNA does not all code to protein like all DNA non coding sequences undergo mutation so individuals acquire different base sequences
-‘‘SNPS’ Single base differences, Strands for single nucleotide polymorphisms
- Regions of DNA that varies about twenty - forty base sequences long often repeated many times. called Hyper variable regions or short tandem repeats
Genetic or DNA fingerprints or profile
Terms for a pattern unique for each individual related to the base sequences of DNA
Natural selection
Gradual process in which inherited characteristics become more or less common in a population, in response to the environment determining the breeding success of individuals processing those characteristics
Process of natural selection from biodiversity
- Mutation due to differences in DNA
- Variation, different physical appearance, biochemical function or behaviour
- competitive advantage, Some are more suited to the environment than others and outcompete rivals for resources
- Survival of the fittest, Those more suited to the environments survive better
- Reproduction, those more suited to the environment have more offspring
- Pass advantageous alleles to offsprings, Offspring inherits the advantageous allele so they are more suited to the environment
How natural selection generates biodiversity
As a habitat undergoes change individuals with allioles are more suited to that environment will reproduce more efficiently until many of the population will have that feature
But if the environment changes again the different features are more useful and they will be selected over many generations, makeup of population changes: generatIng biodiversity
How natural selection decreases by biodiversity
May happen when a selective insecticide kills all the Afids in a habitat for when an asteroid crashes into the Earth. Process occurs in sections that will eventually reduce an organism or make them go extinct
Adaptation
The change in a species, as a useful characteristic becomes more common
The useful characteristic is referred to as an adaptive trait and every aspect of an organism is subject to adaptation and adaptive traits may be seen in many features
Anatomical traits
- Shark dolphins in Penguins have streamlined bodies. Without this body shape they would be less effucient catching food or escaping predators
- Some plants have flowers with honey or nectarides they indicate the centre of a flower and source of nexum pollen for visiting insects. A flower without these lines would attract fewer polinators
Psychological traits
- Mammals and birds are endothermic and must avoid wasting energy trying to maintain body temperature in the cold
- Leaves fall off deciduous plants when temperature and light intensity decrease in autumn. Maybe don’t lose water by transpiration and risk dehydration through winter when water may be frozen so survive cold weather
behavioural traits
- Like many plants, Flowers in spring when it’s pollinating insects have emerged. If it’s flowered earlier it would not be pollinated
- Meeting rituals in animals include the displaying of Peacock’s tail or the elaborate dances by flamingos increasing animal’s chance of reproducing
