4.1.3 CLASSIFICATION AND EVOLUTION Flashcards
Hierarchy
Smaller groups arranged within
larger groups
There is also no overlap between
groups
Taxon
The term for each group in a
classification hierarchy
Binomial system
A universal naming system for
species
Individuals are named after their
genus and species
E.g. Homo sapiens
The genus has a capital letter, the
species has a lower case letter
Species
A group of similar organisms that
can breed to make fertile offspring
The five kingdoms
Prokaryotae
Protocista
Fungi
Plantae
Animalia
What are the taxa
in the Linnaeus
classification
system?
Kingdom
Phylum
Class
Order
Family
Genus
Species
Basis of
classification
systems
Originally only based on observable
features
Now…
Compare DNA/mRNA base
sequence
Compare amino acid sequence
Phylogeny
The study of species’ evolutionary
origins and relationships
Evolution
The change in allele frequency over
many generations in a population
Driven by natural selection
Types of variation
Intraspecific variation
Interspecific variation
Continuous variation
Discontinuous variation
Intraspecific
variation
Differences between members of
the same species
Interspecific
variation
Differences between members of
different species
Continuous
variation
Traits have numerical values
Traits controlled by many genes
The environment can have an
impact
Represented on a histogram
Discontinuous
variation
Traits have discrete categories
Traits controlled by a single gene
The environment has no impact
Represented on a bar chart
Types of
adaptations
Anatomical
Behavioural
Physiological
Anatomical
adaptation
Internal or external physical
features
Behavioural
adaptation
Changes in the ways organisms act
Natural selection
The process that leads to evolution
in populations
Results in species that are better
adapted to their environment
surviving and reproducing, passing
on their alleles to the next
generation
Sampling by
density
Counting the individuals present in
the frame you are investigating
Sampling by
frequency
Percentage of quadrat squares the
species are present in
Sampling by
percentage cover
Estimating the percentage of the
entire quadrat covered with the
species that is being investigated
