According to the endosymbiosis theory, scientists believe that early eukaryotes formed from prokaryotes. Why do scientists believe that prokaryotes existed earlier than eukaryotes?
A.
All prokaryotes are aquatic in nature.
B.
All prokaryotes perform photosynthesis.
C.
Prokaryotes have organelles, while eukaryotes do not.
D.
Certain eukaryote cell structures resemble prokaryotes.

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

Abnormal softening of a gland is known as

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.