5.3 Classification of biodiversity Flashcards
What is the binomial system?
The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses.
When species are discovered they are given scientific names using the binomial system.
It consists of two words, the first name is the genus name. A genus is a group of species that share certain characteristics. The second name is the species or specific name.
What is a genus
A genus is a group of species that share certain characteristics. CAPITAL LETTER
What are the two names of the binomial system?
It consists of two words, the first name is the genus name. A genus is a group of species that share certain characteristics. The second name is the species or specific name.
What are the rules of the binomial system?
The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses.
When species are discovered they are given scientific names using the binomial system.
It consists of two words, the first name is the genus name. A genus is a group of species that share certain characteristics. The second name is the species or specific name.
1) The genus name begins with a capital letter and the species name with a lower case letter.
2) in hyped or printed text, a binomial is shown in italics
3) After the binomial name has been used once in the text it can be abbreviated to the initial letter of the genus name with the full species name.
4) The earliest published name, for a species, from 1753 onwards for plants, or 1758 for animals is the correct one.
What does taxa mean?
is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit.
What are the three domains all organisms are classified into>
It used to be 2, as prokaryotes and eukaryotes however this is now wrong as we have realised the diversity of prokaryotes.
So now we use: Eubacteria, Archaea and Eukaryota.
What are Eubacteria, Archaea and Eukaryota?
They are the three domains all organisms are categorised into.
What are Archatea?
A DOMAIN
microorganisms which are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient group which is intermediate between the bacteria and eukaryotes.
They are found in the ocean surface, deep ocean sediments and even oil deposits far below the surface of the earth. They are often found in extreme habitats such as water with a very high salt content or temperatures close to boiling. The methanogens are obligate anaerobes and give off methane as a waste product of their metabolism.
- They have proteins similar to histones bound to their DNA.
- Introns present in some genes
- The cell walls are not made of peptidoglycan
- The cell membrane is made of glycerol-ether lipids; unbranched side chains; I-form of glycerol
What are Bacteria?
A DOMAIN
- No histones
- No introns
- Cell walls made of peptidoglycan
- Glycerol-ester lipids, unbranched side chains and d-form of glycerol
What are Eukaryota?
A DOMAIN
- They have histones
- Have introns
- Cell walls not always present and not made of peptidoglycan
- Cell membrane made from glycerol ester lipids, unbranched side chains, d-form of glycerol
Where do virus’s sit in the classification system?
Virus’s are not classified as any three of the domains. Although they have genes coding proteins using the same genetic code as living organisms they have too few of the characteristics of life to be regarded as living.
How do taxa do down once you have established they are Eukaryota?
Kingdom Phylum Class Order Family Genus Species
What are the four kingdoms?
Plants, animals, fungi and protoctista.
What are protist?
The singular of protoctista. A protist is any eukaryotic organism that has cells with nuclei and is not an animal, plant or fungus.
What is natural classification?
All members of a genus or higher taxon should have a common ancestor.
What would be unnatural or artificial classification?
Unnatural or artificial classification would be one in which birds, bats and insects are grouped together for example simply because they all fly. This is wrong, flight evolved separately in these groups and as they do not share a common ancestor they differ in many ways. It would not be appropriate to classify them together other than to place then all in the animal kingdom.
What are some advantages of natural classification?
Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.
1) Identification of species is easier. If an unknown specimen is found then it can be identified by at first assigning it to its kingdom and then the phylum etc. Dichotomous keys can help with this.
2) As the members of a group have evolved from a common ancestral species, they inherit similar characteristics and therefore it allows us to predict the characteristics of species within a group. For example, if a chemical that is useful as a drug is found in one plant in a genus then it is likely to be found in other species in the genus.
What is a dichotomous key?
A dichotomous key consists of a numbered series of pairs of descriptions. One matches the organism and one does not.