The strong, lower part of the mantle
between the asthenosphere and the outer
core

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.

Nucleic acids offer variability because they contain alternate forms of genes called .

Bio molecules are essential to all living things. which biomolecule is “d” from the table