Answer:Wildebeest are considered keystone species because their presence has myriad effects on the ecosystem, unlike those of any other species. Wildebeest are the "lawnmowers" of the Serengeti grassland. They keep grass short which in turn reduces the frequency of fires.
Answer:
If we could see your choices, it would better help us to help you.
Explanation:
But, if you are referring to the most widely accepted theory:
Anthropogenic (man-made) Global Warming, or AGW. The theory states that man-made greenhouse gases, primarily carbon dioxide (CO2 ), are the predominant cause for the global warming that has occurred during the past 50 years.
Answer:
c.
Explanation:
the chromosomes are duplicated.
If the ice is lying on land, melting ice will slowly raise sea levels.
Explanation:
Ice in the Arctic ocean is floating on the ocean and so when it melts it does not raise sea levels anymore - its like ice cubes in a drink - its already displaced as much water as its going to.
However, the big ice caps of Antarctica and Greenland are mostly lying on land and so as they melt they add more water to the oceans and the average sea level rises.
If all the ice in Greenland were to melt the sea level would rise by about 7 meters which would flood out millions of people living in coastal cities. If all the ice in Antarctica were to melt, this would add 72 meters to average sea levels.
Right now, thermal expansion of the oceans, plus melting ice from continental alpine glaciers, is contributing the most to sea level rise (as the atmosphere warms from global warming, some heat is transferred to the oceans). Current estimates are that sea levels may rise as much as 1 meter (3-4 feet) by the year 2100.
