null
US
Sign In
Sign Up for Free
Sign Up
We have detected that Javascript is not enabled in your browser. The dynamic nature of our site means that Javascript must be enabled to function properly. Please read our
terms and conditions
for more information.
Next up
Copy and Edit
You need to log in to complete this action!
Register for Free
5239577
Classification
Description
AS - Level BY2 Mind Map on Classification, created by Shehzeb basharat on 25/04/2016.
No tags specified
by2
as - level
Mind Map by
Shehzeb basharat
, updated more than 1 year ago
More
Less
Created by
Shehzeb basharat
over 8 years ago
40
0
0
Resource summary
Classification
Phylogenetic Classificaion
Reflecting evolutionary relateness
Phylogenetic tree
Diagram showing evolutionary descent
Living organisms at the top of the branches
Ancestral species in the branches & trunks
Branch points represent common ancestors
The further up you go, the further up in time
Species in the branches are extinct
Classification is hierarchal
Hierarchal= A system of ranking in which small groups are components of larger groups
Moving down the Hierarchy organisms in a taxon are more closely related
Each grouping in a system is called a Taxon
Taxon = Any group within a system of classification
Taxa are discrete
I.e They can only belong in 1 taxon & no other
E.g This picture
Exoskeleton & jointed limbs are the same
As well as the same No. of limbs
But have different No. of wings, which places them in different taxa
Hierarchy of biological classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Purpose of a classification system
Lets us infer evolutionary relationships
E.g if 2 organisms are very similar we put them in the same taxon
We infer that they are closely related
Easier for communication
E.g it's easier to say 'Bird' than 'vertebrate egg-laying biped with feathers & beak'
When describing the health of an ecosystem/rate of extinction
It is more useful to refer to families than species
The 3 domain system
The largest taxon
Defined on basis of DNA & rRNA sequences
Domains
Eubacteria
Normal Bacteria
Archaea
Extreme Bacteria
Eukaryota
Animals, Plants, Fungi, Protoctista
The 5 Kingdom System
Prokaryotes
Prokaryota
Eukaryotes
Animalia
Plantae
Fungi
Protoctista
Species
A group of organisms that can interbreed to produce fertile offspring
Relatedness of organisms
Theory of evolution suggests that all species have a common ancestor
Assessing relatedness w/physical features
When looking at how closely-related 2 species are
Biologists look for homologous structures
Homologous Structures
Similar structure of component to perform a different function
May have similar developmental origin
E.g Pentadactyl Limb
Limb w/5 digits
But adapted for different functions
Divergent Evolution
Where a common ancestral structure has evolved & performs different functions
Analogous strucutures
Have corresponding function & similar shape
But different origin
Assessing relatedness w/genetic evidence
DNA sequences
During course of evolution species undergo changes in their DNA base sequences
Which eventually accumulate until organisms become different species
The more closely related a species the more similarity in their DNA sequences
DNA analysis confirms/ corrects evolutionary relationships
DNA hybridisation
Comparing DNA base sequences of 2 species
To work out how closely related 2 species are:
1) DNA is extracted & fragmented
Fragments are mixed together
Complementary base sequences hybridise
This gives a percentage
Amino acid sequences
Sequence of amino acids are determined by the sequence of DNA
The degree of similarity in the amino acid sequence of same proteins reflects how closely related they are
Immunology
Proteins of different species can be compared using immunological techniques
If antigens of one species is mixed w/specific antibodies of another
The antigens & antibodies make a precipitate
The closer the evolutionary relationship the more precipitate is made
The species concept
The Morphological definition
If 2 organisms look very similar they are likely to be of the same species
Morphology = The literal shape/form of the organism
The Reproductive definition
If 2 organisms are of the same species
They can interbreed to produce fertile offspring
The Binomial System
Naming system given to organisms of all species
Made up of Genus name & Species name
The names are unambiguous & can be understood worldwide
Regardless of language spoken
How to use the binomial system
Genus name is 1st & 1st letter is capital
Species name is 2nd & all lowercase
Both name written in italics & underlined
Media attachments
69bd17a7-bf95-46f2-95b5-bf17e32587f3 (image/jpg)
8b4b6db9-59d3-4265-bc3b-a5cbb09025ac (image/jpg)
d7b5f348-beee-4a36-97a8-c56e51043cab (image/jpg)
ab351e64-89c0-4602-aa63-4b2415b5658a (image/jpg)
b990f3cd-f9b0-451a-b6fc-f2724d0cf1f0.PNG (image/PNG)
Show full summary
Hide full summary
Want to create your own
Mind Maps
for
free
with GoConqr?
Learn more
.
Similar
GCSE Biology - Homeostasis and Classification Flashcards
Beth Coiley
F212: Classification, Biodiversity & Evolution
helen.rebecca
Classification
rebeccachelsea
B2 Quiz // Flashcards
jaspreet.natt
Biology Classification
Anya Jayakody
Characteristics of the Five Kingdoms - GCSE Biology
Beth Coiley
Biology AQA 3.2.8 Taxonomy
evie.daines
5.3 Classification of Biodiversity
Steve Harton
Bacteria
Merike Mikkov
Kingdom Cards
Deborah Eidson
The Cardiac Cycle
WKatie
Browse Library