Many desert species have adapted to an ecosystem with limited water and food availability with concentrated or "dry" bodily excretions, and the ability to effectively store fat. Burrowing is a common trait for desert mammals as a way to contend with the heat. Diluted urine excretions would not be advantageous in a desert ecosystem because the body would be expelling water inefficiently.

When corals eject their intracellular symbiotic organisms, their color is lost along with the zooxanthellae's photosynthetic ability. This leads to the death of the coral. Algal blooms simply involve the rapid growth of algae over a short period of time. Upwelling involves the process by which deep, nutrient-rich water rises up and gets mixed with the water higher in the ground.

The correct response is tundra. The tundra biome is characterized by permafrost and its lack of trees. The soil is frozen year-around, which prevents large vegetation growth. The tundra is located at high latitudes above the 60^o line.

The correct response is tropical rainforest. The tropical rainforest biome has by far the highest annual precipitation (300-450 centimeters per year) and highest average temperature (25-35 C). The subtropical desert and savanna are incorrect answer choice because they have low precipitation. Boreal forest and temperate rainforests have lower temperature than tropical rainforests. 

The correct response is estuaries. An estuary supports a diverse community of species. The unique distribution of aquatic conditions caused by the mixing of a salty ocean and a freshwater river make estuaries a novel aquatic biome. The pelagic zone and coral reefs are specific to the ocean environment, so those are incorrect responses. 

The correct response is edge effects. The edge effects specifically describe shifts in biodiversity along the edge of a habitat, or in a transition zone that contains features from two habitat types. For example, imagine you are walking on a trail that starts in a forest and leads into a grassy meadow. The transition between forest and meadow would experience edge effects. This area would have species from the forest and species from the meadow living in the same zone.

Though prejudice against indigenous peoples is not a primary cause of deforestation, many indigenous cultures go extinct, much like endemic species, when their lands are taken from them.

A species is deemed 'invasive' instead of merely 'alien' or 'exotic' when it begins to populate an area specifically to the detriment of native species. All the reasons listed above are reasons why an invasive species may be placed in that category.

Critical habitat is defined as vital for sustaining endangered or threatened populations. The whooping crane is endangered and requires wetland ecosystems to sustain a population, while the other examples are situations where alternative (albeit less successful) habitat was available or the population was neither threatened nor endangered.

Amphibians are one of the most susceptible groups of species to mass extinction, with one in three currently at risk of extinction.