Quick questions on Levels of biodiversity (genetic, species, ecosystem): QCE Biology Unit 3

Genetic biodiversity is the variation of alleles within a species, both within a single population and between populations.

Species biodiversity is the number and relative abundance of species in a defined area.

Ecosystem biodiversity is the variety of habitats, communities and ecological processes within a region.

The cheetah (Acinonyx jubatus) is the classic case of low genetic biodiversity. A population bottleneck around 10 000 years ago left cheetahs so genetically uniform that skin grafts between unrelated individuals are not rejected. The species is vulnerable to disease outbreaks for this reason.

Coral species such as Acropora millepora show measurable variation in heat-shock protein alleles between northern and southern reefs, and individuals with these alleles bleach less readily.

The reef supports about 1500 fish species, 400 coral species, six of the world's seven marine turtle species and over 30 species of marine mammal.

Within the reef system there are coral reef, seagrass meadow, mangrove forest, lagoon and deep slope ecosystems, each with different physical conditions and species.

Define biodiversity at the genetic, species and ecosystem levels, giving one Australian example of each. [3 marks]

A reef survey records 25 species across three sites, but Site A holds 90 percent of one species while Sites B and C are more even. Identify which site has lower species evenness and explain how this affects biodiversity scoring. [3 marks]

Refer to a Queensland conservation reserve. (a) Identify one threat at each biodiversity level. (b) Predict the consequence of losing 50 percent of a top predator population.