Classification and Evolution, 4.3 Flashcards
What is classification?
Process helping to identify an organism by putting it into a group
What is phylogeny?
Study of evolutionary relationships between organisms
What is taxonomy?
The way in which biologists put organisms into groups
What is DOMAIN? Give the groups
Highest taxonomic rank. Archaea. Eubacteria. Eukaryote.
What is KINGDOM? Give the main types
Traditionally there are 5 main Kingdoms. Plantae. Animalia. Fungi. Protoctista. Prokaryote.
What is PHYLUM?
Contains all groups of organisms that have the same body plan eg possession of a backbone
What is CLASS?
A group of organisms that posses the same general traits eg number of legs
What is ORDER?
Subdivision of class using additional info eg meat eating (carnivore)
What is FAMILY?
Group of closely related genera
What is GENUS?
Group of closely related species
What is SPECIES?
A basic unit of classification. All members of the same species, show some variation
Define binomial naming system
A system that uses the genus name and the species name
How is a name written using the binomial naming system?
Genus - starts with capital. Species - lowercase. eg Homo sapiens. Should be underlined or in italics
Why is it easier too use the binomial naming system?
Because in different languages organisms will have different names. This way it is the same.
What is the description of a Prokaryotae?
No nucleus - naked loop of DNA. No membrane bound organelles. Smaller ribosomes. Free living or parasitic.
What are some examples of a Prokaryotae?
E.coli - rod shaped
What is the description of a Protoctista?
Eukaryotic. Have a nucleus. Most single celled. Huge diversity - don’t fit into the other groups. Plant and animal like features. Can be autotrophic or heterotrophic. Most free living.
What is an example of a Protoctista?
Paramecium
What is the description of a fungi?
Eukaryotic. Single celled or have mycelium made of hyphae. Walls made of chitin. Cytoplasm - multi nucleate. Free-living. Extracellular dugestion
What is an example of a Fungi?
Bakers yeast.
What is the description of Plantae?
Eukaryotic. Multicellular. Have a cellulose cell wall. Are autotrophic. Contain chloroophyll.
What is the description of Animalia?
Eukaryotic. Multicellular. Heterotrophic. Able to move around.
Why are observable features only useful to an extent?
Organisms will adapt to their environment and may appear similar. For example dolphins and sharks.
What is Cytochrome c?
Protein used in the process of respiration. It is in all respiring organisms but isn’t identical in all species.
How can we use Cytochrome C to classify organisms?
Can compare amino acid sequences to see how closely related they are. The more differences there are the less closely related the species are.
How can we use DNA to classify organisms?
DNA is different but found in all living organisms. We can compare the DNA. Changes can occur in the sequence through mutations. The more similar the DNA is the more closely they are related.
Apart from DNA and Cytochrome c what else can we use in classification?
RNA
What was the old Kingdom of Prokaryotae split into?
Bacteria and Archaea
How were the new groups Bacteria and Archaea determined?
Based in RNA. Have structural differences.
What are some of the features of Bacteria that are different to Archaea?
Different cell membrane structure, Flagella with different internal structure. Different enzymes for synthesizing RNA. No proteins bound to thei genetic material.
Why are archaea similar to eukaryotes?
Similar protein synthesizing enzymes. Similar mechanisms for DNA replication.
What is artificial classification?
Divides organisms by physcial characteristics
What are the limitations of artificial classification?
Limited information. Doesn’t reflect evolutionary relationships
What is natural classification?
- Evolutionary relationships
- Uses many characteristics
- Classifies using shared features derived from ancestors
- Arranges groups into a hierarchy
What is phylogeny?
Study of evolutionary relationships between organisms
What can we use a phylogenetic tree for?
To see how closely related species are as at some point in the past two species will have a common ancestor
What is natural selection?
How features of the environment apply a selective force on the reproduction of individuals in a population
Why is variation the key to a species survival?
Competition for food and resources - some are better adapted and will survive long enough to reproduce
What observations did Darwin make that helped lead to the theory of evolution?
- Offspring appear similar to parents
- No two individuals are identical
- Organisms can produce large numbers of offspring
- Populations in nature remain stable in size
What evidence is there for evolution?
Fossils and biological molecules
How are fossils evidence for evolution?
- Showed in the past there were different species than there are today
- Old species died out and new ones have arisen
- Differences between fossil species and modern species eg size
- Species had a lot of similarities
- Horse has the most complete fossil collection
How are biological molecules evidence for evolution?
- Certain molecules throughout organisms, if one species gives rise to another they’ll have the same biological molecules
- Closely related species will have separated recently, identical/ similar molecules
- Cytochrome c
- Structure of DNA
Describe the process of evolution
- Mutation to a gene (name and describe)
- Animals are subject to selective pressures
- More likely to survive and reproduce
- Passed onto the offspring
- Allele frequency increases with each generation
