1. 5.3 Classification of biodiversity
Nature of science:
Cooperation and collaboration between groups of scientists: scientists use the binomial system to identify a species rather than the many different local names
Understanding:
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
Taxonomists classify using taxa
All organisms classified into 3 domains
Principal taxa for classifying eukaryotes are: kingdom, phylum, class, order, family, genus, species
In a natural classification the genus and higher taxa have all evolved from one common ancestor
Taxonomists sometimes reclassify groups of species when new evidence shows a previous taxon contains species evolved from a different ancestor
Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group
Applications
Classification of one plant and one animal species from domain to species level
External recognition features of bryophytes, filicinophytes, coniferophytes and angiospermophytes
Recognition features of porifera, cnidaria, platyhelminthes, annelide, mollusca and arthropoda, chordata
Recognition of features of birds, mammals, amphibians, reptiles and fish
Skills
Construction of dichotomous keys for use in identifying specimens

2. Why are supermarkets organised like this?

3. All living things arranged into groups according to their similarities
Classification…
All living things arranged into groups according to their similarities

4. HOW DO IDENTIFY LIVING THINGS?

5. MRS NERG
Remember MRS NERG?

6. Living things notice and react to changes in
7A Signs of life - The meaning of life
M = MOVEMENT
Living things are able to move about. Animals move from place to place. Plants move by responding to light.
S = SENSITIVITY
Living things notice and react to changes in
their surroundings. They can respond to light, heat, sound, taste, sight or touch.
R = RESPIRATION
Living things need energy to carry out the
functions that keep them alive.

7. Living things need to take in food.
7A Signs of life - The meaning of life
N = NUTRITION
Living things need to take in food.
E = EXCRETION
Living things have to get rid of unwanted waste products.
R = REPRODUCTION
Living things produce offspring.
G = GROWTH
Living things grow, increasing in size and complexity.

8. The 3 domains
Eukaryotes
Eubacteria (prokaryote)
Archaea (prokaryote)

10. Complete the table Feature Bacteria Archaea Eukaryota
Histones associated with DNA
Presence of introns
Structure of cell walls
Cell membrane differences

11. Complete the table Feature Bacteria Archaea Eukaryota
Histones associated with DNA
Absent
Proteins similar to histones bound to DNA
Present
Presence of introns
Rare or absent
Present in some genus
Frequent
Structure of cell walls
Made of chemical called peptidoglycan
Not made of peptidoglycan
Not always present
Cell membrane differences
Glycerol-ester lipids; unbranched side chains; d-form of glycerol
Glycerol-ether lipids; unbranched side chains; l-form of glycerol
Glycerol-ether lipids; unbranched side chains; d-form of glycerol

12. Eukaryotes are classified using principal taxa
Classification
Eukaryotes are classified using principal taxa
Kingdom
Phylum
Class
Order
Family
Genus
Species K P
Crisps
Only
For
Good
Students

13. Try to guess who this is…
Who am I?
Try to guess who this is…
Kingdom
Phylum
Class
Order
Family
Genus
Species
Animalia
Chordata
Mammalia
Carnivora
Canidae
Canis
lupus

15. The same species can have many different local names.
Naming species
The same species can have many different local names.
Lords and ladies
Cuckoo pint
Devils and angels
Cows and bulls
Willy Lily
Snakes meat
Arum maculatum

16. Naming species Cooperation and collaboration between scientists
Ensures all scientists use same names
Decided by different animal and plant congresses

17. Use two names: the genus and species
Binomial system
Use two names: the genus and species
Rules:
Genus name begins with upper case letter and species name with lower case
Italics
Can be abbreviated once used already: A.maculatum

18. Natural classification
Classify organisms in a way that closely follows evolution
Members of a genus should have a common ancestor
Members of the group share many characteristics
Unnatural classification – grouping birds, bats and insects because they fly
Flight evolved separately in these groups and they have very big differences otherwise

19. Advantages of natural classification
Identification of species is easier
Go through each taxa step by step – assign a kingdom, then a phylum etc…
Dichotomous keys can be used to help with the process
Could do no easily with unnatural classification
2. Prediction of characteristics
Inherited similar characteristics from common ancestor
Could not do this if we used unnatural classification
E.G find a new species of bat – we know it has mammalian features (could not do if grouped with birds)

20. Reclassification
New evidence may show that members do not share a common ancestor
Split group up into more taxa
(or two groups are found to be more similar – merge the groups)

21. Creating the dichotomous key
We group all living things are group due to their similarities…

22. What are these?
BIRDS

23. What are these?
MAMMALS

24. What are these?
FISH

25. We can create a dichotomous key to split these animals up.
To do this we need to ask questions about them to find their differences.
How are fish, mammals and birds different?

26. BIRDS
Feathers
MAMMALS
Fur
FISH
Scales

27. This is how we construct a dichotomous key…
Does it have scales?
yes
Does it have feathers? no
yes no

28. Your task
You need to be able to read classification trees and be able to create your own.
Complete the two classification worksheets (you need to do both of them yourself)
Create your own classification key using 5 animals from the cards provided
Look at page 265 in your book and complete the example of the second type of dichotomous key