Ice platforms in the Arctic are a critical resource for the survival of Arctic animals. Seal pups nurse and rest on the ice platforms for the
first six weeks of life. Recent data suggests that warming sea water and
air temperatures will melt 20 percent or more of the Arctic sea ice over
the next 40 years, disrupting the Arctic food web.
Based on the partial Arctic food web,
melting sea ice might lead to a
decrease in the number of -
polar bears
Partial Arctic Food Web
Arctic cod
Polar bear
Killer whale
Arctic birds
Seal
D phytoplankton
Arctic birds
Arctic cod

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.

the sphincter muscles at the end of the digestive tract is the anus.