Achalasia is a disorder that prevents food from traveling to the stomach. It occurs when the lower part of the esophagus, the tube leading from the throat to the stomach, does not open up to allow food to enter the stomach.

Which body systems are not functioning properly, causing the symptoms of this disorder?

Describe how alleles and genes are related

African penguins, which inhabit the coasts of southern africa, were classified as an endangered species in 2010. two significant threats to their survival are ecosystem damage from oil spills and overfishing by humans. overfishing depletes the food supply of african penguins. the best method to reduce the threat of overfishing would be to . the risk of oil spills could be reduced by increasing the use of , which should oil consumption. if an oil spill does occur, could be used to remove the oil so the ecosystem may more quickly recover.

How are viruses different from eukaryotic cells?