classifcation and biodiversity

Classification system hierarchy

Domain- eukaryoa, bacteria, archaea

Kingdom

Phylum

Class

Order

Family

Genus

Species

Dirty kinky people can often find great sex

What is a species

A group of closely related organisms that are all potentially capable of interbreeding to produce fertile offspring

Analogous features

Features that look similar or have a similar function but are not from the same biological origin

Homologous structures

Structures that genuinely show common ancestors eg limbs

Archaea

One kingdom- Archaebacteria- thought to be early relatives of the eukaryotes, thought to be found in only extreme environments

Bacteria

One kingdom- eubacteria

Eukaryotic

4 kingdoms

Protoctista- very diverse, heterotrophs, autotrophs

Fungi- heterotrophs

Plantae- autotrophs

Animals- heterotrophs

Binomial system

1st name is genus, second is specifies=es, 1st has caps

Importance of species

Help measure biodiversity, monitor effect of changes

Morphological features concept

Physical appearance however variation within species eg sexual dimorphism- male and female look different

Reproductive / biological species concept

A group of organisms w similar characteristics that interbreed to produce fertile offspring

Limitations- dont always live in same area

Lion and tigers make fertile offspring

Good for aminaks not plants

Bacteria- asexual reproduction

Fossil species

Ecological species model

A species definition based on the ecological niche occupied by an organism

Genetic species model

A species model based on DNA evidence

Molecular phylogeny

the analysis of the genetic material pf organisms to stability their evolutionary relationships

Mate recognition species model

Based off unique fertilisation behaviours

Evolutionary species model

Based on shared evolution between groups of organisms

Why do species change

New techniques eg dna profiling

Gel electrophoresis

Restriction enzyme cuts the DNA into fragments

Added to agarose gel w dye

Covered w buffer solution

Current, goes to positive anode

Fragments move at different rates based on mass

Put under uv light

Compare banding patterns

DNA sequencing

The process by which the base sequences of all pr part of the genome of an organism is worked out

DNA proofing

The process by which the non coding areas of dna are analysed to identify patterns

DNA barcoding

Uses a small sample of dna- easy to exact and sequence

Has non variable flanking regions that the fragments can be easily cut out so that appropriate primers can be made for the PCR (Yr 13)

CO1 gene used

Not good in plants- evolves too slowly - matK and rbcl used

Evidence for science

Scientific journal, peer reviewed, scientific conference

Artificial classification

Based off morphological similarities and differences, not how they evolved or how closely related they are to

Eg birds and butterfly’s together- wings, analogous features

Natural system

Darwin theory of evolution

Phylogeny- evolutionary history

Common ancestor, everyone had one 3 billion years ago, archaea and eukaryota was 2 billion yrs ago

Homologous structures

5 kingdoms

Partially phylogenic, many proyarkotes were put under monetary- similar morphology- artificial class

Monetary, protoctist, fungi, plants, animals

Became 6 as monera split into archaea and bacteria

3 domains

3 domains w 6 kingdoms, bacteria- eubacteria, archae- arechaebacteria and eukarya- protocista, fungi, plants and animals

Theory of evolution

Living organisms that reproduce sexually have a variety in apperanc

Produce an excess of offspring- many do not survive, competition

The evolution of organisms occur as a result of the differential fertility and survival of organisms w different genotypes leading to different phenotypes within a specific environment, those alleles that deliver the adaptions best suited to the environment are most likely to be passed onto the next gen

Ecology

The study of the interactions of organisms w each other and w the environment they live in

Niche

The role of an orgbaims within the habitat in which it lives

Species adapts to its niche

Anatomical adaptations

Involves form and structure of organism

Physiological adaptation

An adaptation involving how the body of the organism works, including differences in biochemical pathways or enzymes

Behavioural adaptations

An adaptation involving programmed or instinctive behaviour making the organism better adapted for survival

Natural selection

The mechanism for evolution is natural selection

-variation in species, sometimes caused by random mutations

-environment causes selection pressures

-overpopulation bc excess offspring but stable population size- competition

-bretter adapted organisms are more likely to survive selection pressures

Reproduce and pass on ALLELES

Over many generations, allele freq changes

Speciation

The formation if a new species

Reproductive isolation

Occurs when organisms cannot interbreed to produce fertile offspring

Synpatric speciation

Speciation that rakes place between populations living in the same geographical area

Interbreeding and gene flow are reduced by ecological isolation, temporal isolation, behavioural isolation, mechanical isolation and hybridisation

Geographical isolation

Occurs when a physical barrier such as a river reproductively isolates members of a species from the original population

Leads to allopatric specification

Endemic species

A species that evolves following geographical isolation and which is found in only that one place

Adaptive radiation

A process by which an isolated species evolves rapidly to form a mulberry of different species filling different ecological niches

Ecological isolation

Occurs when two populations inhabit the same region but develop adaptations to different parts of the habitat w different biotic or abiotic factors- leads to sympatric speciation

Temporal isolation

Occurs when the timing of key events in the reproductive cycle eg flowering or sexual receptiveness drift away from the normal in one part of the population- leads to sympatric speciation

Behavioural isolation

Occurs when changes in mating behaviour result in some species not recognising each other as potential mates- sympatric speciation

Mechanical isolation

Occurs when a mutation occurs which makes it impossible for organisms in part of a population make it physically impossible to mate w the rest of the population- leads to sympatric speciation

Hybridisation

Two closely related species can sometimes breed to produce offspring- chromosome arrangement can allow the plant to be fertile w similar chromosome arrangements but not w parental plants- sympatric speciation

This is post zygotic not pre

Antibiotic resistance

Random mutations, selection pressure, competition, resistant bacteria have selective advantage for survival, divide by binary fission and pass on allele, freq increases

Why can allele freq change so fast in prokaryotes

Single copy of each gene so alleles expressed immediately

Antibiotic resistance is often in plasmids so can be transferred quickly - horizontal gene transfer

Short life cycle

Plasmids can be replicated independently eg during bacterial conjugation

Factors contributing to antibacterial resistance

Inappropriate use- viral injections

Wide spectrum antibiotics

Failure to complete course

Lack or research and financial investment

Bad hygiene

Less use, education, prizes, less use in animals can help

Evolutionary race

Resistance soon after antibiotic given, takes longer to develop new one than for resistance to form