Which Group's Members Have Had Both Lungs and Gills During

Question

Which group's members have had both lungs and gills during their adult lives?
A) sharks, skates, and rays
B) lungfishes
C) lancelets
D) amphibians
E) ichthyosaurs and plesiosaurs

Accepted Answer

Lungfishes are the only group of animals that have both lungs and functional gills during their adult lives. They are able to use their gills in water with low oxygen levels, and their lungs in air or water with higher oxygen levels. Sharks, skates, and rays only have gills, lancelets only have pharyngeal slits, amphibians have lungs as adults but typically only have gills as larvae, and ichthyosaurs and plesiosaurs were extinct marine reptiles that did not have both lungs and gills.