biology

A pond in a temperate deciduous forest fills in with dead leaves and silt and eventually dries up, leading to terrestrial succession. Which sequence of plant communities would inhabit the area during the stages of this succession?

Grasses -> Shrubs -> Trees

Scientists found that, over a period of 200 years, a mountain pond was transformed into a meadow. During that time, several communities of organisms were replaced by different communities. Which of these best explains why new communities were able to replace older communities?

The abiotic characteristics of the habitat changed.

rabbits introduced into Australia over 100 years ago have become a serious pest to farmers. Rabbit populations increased so much that they displaced many native species of plant eaters. What is the most logical explanation for their increased numbers?

There are few effective predators.

When the Mount St. Helens volcano erupted, the blast covered much of the surrounding area with ash. Based on the diagram above, which list shows the sequence of secondary succession

Z, X, Y, W

A wetland was drained to build a mall. Two years later, there were no more toads in that area. A possible reason the toads may have disappeared, is

because the toads got their food from the wetland ecosystem.

mangrove trees grow in the water on the edge of a subtropical island. In time, grass like plants will grow on the same spot. Still later, palm trees will grow there. Given enough tinme (and no natural disasters), all these plants will be gone and a stable pine forest will stands where the mangroves ibce grew. These changed best describe steps in

ecological succesion

the pesticide DDT was used to kill mosquitoes for many years. DDT entered bodies of water, moved up the food chain, and built up in the tissues of fish. When female bald eagles ate these fish, they produced eggs with very thin shells. The eggs broke when the eagles sat on their nests. The U.S. government banned the use of DDT in 1972. Which of these graphs most likely shows how the ban of DDT affected the bald eagle population?

graph b

the diagram below represents the varying biodiversity in three ecosystems the level of biodiversity in ecosystem A is high because it has the

greatest variety

As more people have moved to the beach, the sea turtle population has decreased. Which is most likely the cause of this decrease?

habitat loss

If farmers cleared a large forest and planted grass, the squirrels that had lived in the forest would MOST LIKELY

move to other areas that had trees.

what is a reason why wolves were brought back into yellow stone park

to manage the rising elk population