M4 - Biodiversity and Natural selection Flashcards
What is phylogeny?
The classification of organisms into groups reflecting how closely related they are.
Evolutionary relationships can be shown using a ________ ____ - Showing how long ago two species shared a common ______.
Phylogenetic tree
ancestor
Name the two types of classification.
Artificial and phylogenetic classification
Describe Artificial classification. Why can it be misleading?
Usally based on visible features (e.g. colour, size etc).
Can be misleading as some structures may perform the same function but have different evolutionary origins.
Describe Phylogenetic classification.
Based on evolutionary relationships between organisms and their ancestors.
Taxonomists look for shared anatomical features between species (e.g. vertebrate limb) that must have been present in a common ancestor (ancestral feature).
They also look for the appearance of new adaptations that are unique to a particular lineage.
What are 4 ways that scientists use to look for evidence for contructing phylogenetic trees (how closely related species are)?
- DNA sequencing (compares genome)
- mRNA sequencing (compares only coding sequencing)
- Comparing amino acid sequences (also no introns involved)
- Immunological comparisons
What happens in immunological comparisons?
Blood serum from Species A injected into animal which produces antibodies against Species A proteins.
Antibodies added to blood samples from other species where they bind to proteins of a smiliar structure and form a precipitate.
The more precipitate the closer the relationship to species A.
What is the definition of a species?
Organisms that are genetically similar enough to be able to breed to produce living, fertile offspring .
Courtship behaviour allows individuals to be able to what? (5 points)
1) Recognise members of their own species. - only members of the same species can produce fertile offspring.
2) Identify a mate that is capable of breeding - both partners must be sexually mature, fertile and receptive to mating.
3) Form a pair bond - leading to successful mating and raising offspring.
4) Synchronise mating - females may only be able to conceive during a short time period.
5) Become able to breed - member of the opposite sex in physiological state to allow breeding to occur (e.g. size)
What is classification? What is the name of the branch of science concerned with classification? Who specialises in it?
The process of putting species of living organisms into groups.
Taxonomy
Taxonomists
What is a taxon?
A group of organisms (like a species or genus).
Taxa have a hierarchial order - each taxon contains smaller taxa until the smallest taxa (with no overlap) are reached
What is the taxon hierarchical order? How do you remember this?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Don’t Keep Putting Crumbs Out For Greedy Seagulls
What are the 3 domains?
Archae - very ancient prokaryotic microbes
Eubacteria - more advanced prokaryotic microbes
Eukaryota - all life forms with eukaryotic cells including plants and animals
How do you write an organism’s binomial name using the binomial system?
First name is GENERIC NAME - the genus to which the organism belongs - written with a captical letter.
Second name is SPECIFIC NAME - the species to which the organism belongs - starting with a lowercase letter.
Written in italics.
e.g. Homo sapiens
Define biodiversity.
The number and variety of living things to be found in the world, ecosystem or habitat.
