Biodiversity Answers

An increase in biodiversity generally causes _______.

Organisms can have positive or negative impacts on the ecosystem they live in. The cane toad, or Rhinella marina, was introduced to the Hawaiian Islands in 1932 by sugar cane farmers. Farmers released the toads in their crops to help control pests that were damaging the sugar cane. The cane toad has few natural predators, as it secretes a poisonous toxin from its skin that deters larger organisms from eating it. As a result, the cane toad population thrived and grew to number hundreds of thousands by 1935. Photo by Patrick Gijsbers Which role does the cane toad play in the Hawaiian Islands?

A variety of different mechanisms in nature help create diversity in organism populations. The tundra found in the northernmost parts of the planet is the world’s youngest biome. The tundra is home to a variety of plants and animals. Organisms that can be found in the tundra include shrubs, mosses, caribou, polar bears, and wolves. Which mechanism do the different organism populations found across the tundra exemplify?

When the comb jelly, Mnemiopsis leidyi, was introduced into the Black Sea, its population exploded to 500 comb jellies per cubic yard in 1988. The jellies devoured all the zooplankton and fish larvae, drastically reducing the numbers of the native fish populations. This situation demonstrates _______.

Consider the following food chain: Plants are eaten by grasshoppers, which are eaten by mice, which are eaten by snakes. What would happen to the other members of the food chain if the plant population was wiped out?

Which of the following statements about migration is true?

A mutation that causes resistance in a population of beetles is an example of _______.

Macroevolution occurs within a population.

The water hyacinth is an invasive species that can spread extremely fast, blanketing a water surface in a very short period of time. It can limit boat traffic, swimming, and fishing, and it can deprive native plants and animals of sunlight and oxygen, thus reducing the local biodiversity. This situation demonstrates _______.

Ecosystems with greater biodiversity have an increased stability.

Consider the following food chain: Plants are eaten by grasshoppers, which are eaten by mice, which are eaten by snakes. What will happen to snakes in the long term if mice become extinct?

Which of the following is not a possible reason for migration?

An increase in the biodiversity of an ecosystem leads to an increase in its productivity.

Consider the following food chain: Plants are eaten by grasshoppers, which are eaten by mice, which are eaten by snakes. What is likely to happen if a new organism that feeds off mice is introduced?

Consider the following food chain: Plants are eaten by grasshoppers, which are eaten by mice, which are eaten by snakes. What will happen to the other members of the food chain if the grasshoppers are removed?

What is a possible cause for a decrease in ecosystem productivity?

Organisms are dependent on each other for the energy they need to survive. Photos (left to right) by Mehmet Karatay, Jens Buurgaard Nielsen, Furryscaly, and Walter Siegmund What would occur if the snake population is removed from the ecosystem pictured above?