1. Second Semester Exam Review Day 4
7th Grade Science
Second Semester Exam Review Day 4

2. succession
Some ranchers use controlled fires to rid their grazing lands of unwanted plants. These ranchers keep their land in early stages of succession and in a state of equilibrium that is best for their livestock.
Which of these kinds of plants would MOST LIKELY be some of the first plants found growing in a pasture after a fire?

3. When coal lies close to the surface in a mountainous area, mining companies sometimes use a method called "mountaintop removal" to extract the coal. The top of a mountain is blasted off with explosives, removing all of the soil and rock that lie above the coal. The soil is then dumped into nearby valleys and streams, and the exposed ore is mined. The method has caused a lot of problems, including loss of forests, danger from flying debris, and dust clouds from the blasts.
Another environmental problem caused by mountaintop removal is the —

4. Which catastrophic event is most likely to cause an environmental disturbance in a grassland biome?
Explain your answer.

5. What is the most likely result of the fertilizer entering the pond?
Highly developed regions contain large amounts of fertilizers in their soil due to yard maintenance. When these fertilizers are released from the soil, they enter local ponds, where they deposit an unusually high amount of organic matter. This excessive organic matter leads to massive algal blooms.

6. During a landslide, many tons of rock slide down a hill in a very short time. A landslide would MOST LIKELY force animals living in the area to —

7. Rivers start in areas of higher elevation and run towards the ocean
Rivers start in areas of higher elevation and run towards the ocean. The river moves sediment, as well as water. When a river is dammed, it will change the sediment flow of an area. Which change of sediment would be a result of a dam being built?