10.1 species and taxonomy

What is a species ?

A group of animals(similar organisms) that are capable of producing living fertile offspring

What is the binomial system used for nomenclature of organisms?

• A Latin name with two parts is given.

• The first part is the genus name, with a capital letter.

• The second part is the species name with a lowercase letter.

• Names are in italics, or underlined when hand written

What is courtship behavior?

• Carried out by organisms with the aim of attracting a mate of the correct species

• This may involve: Secreting chemicals A dance Colour changing

Why is courtship behavior important ?

• Synchronize mating;where there is maxim probability of the sperm and egg meeting.

• Stimulates the release of gametes

• Recognition of a mate; attract opposite sex that is capable of breeding

• Indicates sexual maturity/fertility

• Can form a pair bond so the pair can reproduce several times

Why do different species look different ?

1. live in a similar environment

2. have a similar selection pressures

3. similar alleles will have the selective advantage

4. produces similar proteins and therefore similar characteristics

What are the two main forms of biological classification?

Artificial Classification
Natural (Phylogenetic) Classification

What is artificial classification?

• division of organisms \n based on obvious differences (colour, size etc.)

• These are described as analogous characteristics where they have the same function but do not have the same evolutionary orgins.

What is phylogenetic classification ?

• division of organisms based on evolutionary relationships.

• based on shared characteristics that have been taken from ancestors \n

• hierarchy of groups formed

• relationships in a phylogentic classification are based on homologous characteristics (similar evolutionary origin)

What is a hierarchy?

• smaller groups arranged with larger groups

• No overlap between groups

What is taxonomy?

The science of classification where organisms are named, and placed into named groups

What are taxa?

Groups used to classify organisms
There are 8 taxa in total
A group is called a taxon

What are the three largest taxa?

Eukarya
Bacteria
Archaea

(called the 3 domains of classfication)

Classification system order

• Domain

• Kingdom

• Phylum

• Class

• Order

• Class

• Family

• Genus

• Species

• Do keep pond clean or froggy gets sick

• Each group is called a taxa

Describe the domain of Bacteria (5)

• 70S ribosomes

• Unicellular

• Murein Cell Walls

• No membrane-bound organelles

• Single loop of DNA, but no histones

Describe the domain of Archaea (5)

• genes / proteins similar to - eukaryotes

• no murein in cell walls

• more complex RNA polymerase

• 70S ribosomes

• CSM - fatty acids attached to glycerol by ether linkages

\- Describe the domain of Eukarya (5)

• mainly multicellular cells

• contain membrane-bound organelles

• membranes contain fatty acids linked to glycerol via ester bonds

• 80S ribosomes

• cell walls chitin / cellulose

What is the eukarya domain divided into ?

5 kingdoms

• Protoctista

• Fungi

• Plantae

• Animalia

• prokaryota

What is phylogeny

• phylogenetic classification arranges species into groups according to their evolutionary origins and relationships

• Phylogeny gives insight into relations of organisms(whos related to who)

• All organisms have evolved from shared common ancestor.this is shown on a phylogenetic tree

What is a phylogenetic tree?

diagram that shows how organisms are related, and has evolved from common ancestors

Why do we need a system to organise species ?

• understand relationships between organisms and keep track of changes

• The system used need to be universal

How do we classify

Orginally based on visible simailarties

More modern and accurate classification methods are

• dna sequence base)

• mRNA sequence base

• Amino acid sequence

• Immunological (comparing in self antibody shape)

Community
Population
Ecosystem

Community - all living organisms within a given area

Population - made up of members of single species, within a given area

Ecosystem - all living organisms and the non living components

what is classification?

Classification using taxonomy
creates a hierarchical system of
organisms based on shared
characteristics.