Biodiversity - Unit 3: Topic 1: Subtopic 1 Flashcards
What does species richness measure?
Number of species in an defined region.
What is Percentage Cover?
The amount of a quadrat that is covered by a particular species. Effective for non moving organisms.
What is percentage frequency?
The number of times a species appear within the quadrant.
Predation
An interaction where one organism (the predator) kills and eats another organism (its prey).
Abiotic factors
Nonliving factors e.g.water, temperature, gases,…
Biotic factors
Living factors e.g.food availability, competition, disease,…
Competition
Biotic: compete for foods, life
Parasitism
One organism benefits and the other is harmed
Commensalism
One organism benefits and the other is unaffected
Mutualism
Both organisms benefit
Spatial scale
Size of area
Temporal scale
The period of time
What is a clade?
A group of taxa representing all of a common ancestors descendants.
Recall the common assumptions of cladistics.
- groups of living things are related to a common ancestor
- lineages bifurcate
- physical changes become increasing different as organisms evolve
What is an out group?
A distantly related organism that does not usually have the characteristics other organisms have.
What is a node on a cladogram?
The place where branches bifurcate (divide/split).
What is a root on a cladogram?
A root is the original common ancestor all of the organisms on the cladogram are redescended from.
Explain what is meant by the cladistic assumption - lineages bifurcate.
Lineages bifurcate means the cladogram branches split into two new branches at each node (no more or less than two).
