The answer is A: Mass extinction.
"Abrupt disappearance of many land and marine species" = extinction of many species.
Answer:
c
Explanation:
Gas exchange. Gas exchange occurs as a result of respiration, when carbon dioxide is excreted and oxygen taken up, and photosynthesis, when oxygen is excreted and carbon dioxide is taken up. The rate of gas exchange is affected by: the area available for diffusion.
D is the correct answer :)
Answer:
multicellular and eukaryotes.