Answer: It reduces the usefulness, productivity, and biodiversity of the land and is one cause of desertification and erosion. Overgrazing is also seen as a cause of the spread of invasive species of non-native plants and of weeds.
Answer:
Populations have variation in traits due to random mutation, crossing over and environmental conditions.
Answer:
b hummingbirds have the ability to hover while drinking nectar
Explanation:
because this allows for power in both the upward and downward beats of the hummingbirds wings
Answer: D. Hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Hypothesis A and B both are suggesting that caffeine intake is related to higher heart rate. But hypothesis B is proving it more certainly by suggesting the affects of caffeine intake on heart rate. As, heart rate of most people will be higher 30 minutes after they drink a cup of coffee is testifying the fact, that higher heart rate is related with caffeine intake.
Therefore, hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Answer:
Nonpoint-source pollution is the opposite of point-source pollution, with pollutants released in a wide area. As an example, picture a city street during a thunderstorm. As rainwater flows over asphalt, it washes away drops of oil that leaked from car engines, particles of tire rubber, dog waste, and trash. The runoff goes into a storm sewer and ends up in a nearby river. Runoff is a major cause of nonpoint-source pollution. It is a big problem in cities because of all the hard surfaces, including streets and roofs. The amount of pollutants washed from a single city block might be small, but when you add up the miles and miles of pavement in a big city you get a big problem.
In rural areas, runoff can wash sediment from the roads in a logged-over forest tract. It can also carry acid from abandoned mines and flush pesticides and fertilizer from farm fields. All of this pollution is likely to wind up in streams, rivers, and lakes.
Airborne pollutants are major contributors to acid rain. It forms in the atmosphere when sulfur dioxide and nitrogen oxides combine with water. Because acid rain results from the long-range movement of those pollutants from many factories and power plants, it is considered nonpoint-source pollution.
Explanation:
