Diversity Flashcards
(31 cards)
What is a species
a group of organisms that can interbreed and produce fertile offspring
What is the binomial system
• first name: genus
• second name: species
What is classification
The organisation of living organisms into groups
What are the two forms of classification
• artificial classification
• phylogenetic classification
What is artificial classification
- divides organisms based on certain features e.g. leaf shape
- this is known as analogous characteristics, where they have the same function but not the same evolutionary relationships
What is phylogenetic classification
- based upon evolutionary relationships
- classifies species into groups using shared features that have been derived from their ancestors
- arranges groups into a hierarchy
- this type is based on homologous characteristics (these have similar evolutionary origins regardless of their function)
What are homologous characteristics
these have similar evolutionary origins regardless of their function
What are analogous charactersitics
Where they have the same function but not the same evolutionary relationship
What are the 3 domains
• Bacteria
• Archaea
• Eukarya
What kingdoms is the eukarya domain split into
- protoctista
- fungi
- plantae
- animalia
What is the order of the hierarchal system
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is phylogeny
- the evolutionary relationship between organisms
- usually represented by a tree-like diagram
Features of bacteria
(Group of single celled prokaryotes)
• Absence of membrane-bounded organelles
• Unicellular
• Ribosomes are smaller (70S) than in eukaryotic cells
• Cell walls are present and made of more in (never chitin or cellulose)
• Single loop of naked DNA made up of nucleic acids but no histones
How do archaea differ from bacteria
(Group of single-celled prokaryotes)
• their genes and protein synthesis are more similar to eukaryotes
• their membranes contain fatty acid chains attached to glycerol by ether linkages
• there is no murein in their cell walls
• they have a more complex form of RNA polymerase
Features of eukarya
(Group of organisms made up 1 or more eukaryotic cells)
• Their cells possess membrane -> bounded organelles such as mitochondria and chloroplasts
• They have membranes containing fatty acid chains attached to glycerol by ester linkages
• Not all possess cells with a cell wall, but where they do it contains no murein
• Ribosomes are larger (80S) than in bacteria and archaea
Courtship behaviour allows individuals to:
• Recognise members of their own species
• Identify a mate that’s capable of breeding (sexually mature)
• Form a pair bond (lead to successful mating and raising of offspring)
• Synchronise mating (takes place when there’s the maximum probability of the sperm and egg meeting)
Different ways we can make comparisons between and within species:
- comparison of observable characteristics
- comparison of DNA base sequence
- comparison of the base sequence of mRNA
- comparison of amino acids sequences in proteins
Comparison of observable characteristics:
This method is based on the fact that each observable characteristic is determined by a gene (s) -> with environmental influences
Limitations of comparison of observable characteristics
A large no. of characteristics are coded for by more than 1 gene (polygenic)
-> characteristics can also be modified by the environment
Comparison of DNA base sequences:
- DNA contains a lot of information about the evolutionary history of all organisms
- comparing the DNA + proteins of different species allows us to determine the evolutionary relationship between them
Comparison of the base sequence of mRNA
The bases sequences on mRNA are complimentary to those of the strand of DNA they were made
Comparison of amino acids sequences in proteins
The sequence of amino acids in a protein is determined by the DNA
What is biodiversity
The number and variety of living organisms in a particular area
What are the components of biodiversity
• species diversity
• genetic diversity
• ecosystem diversity
