Part 2: Crossword Puzzle

part2

An online crossword puzzle with 10 words. Play it free at AgileCrosswords.com.

Clues

_ exchange system maximizes the concerntration gradient for gas disfusion in internal gills.
Adult organisms with external gills.
2,3-diphosphoglycerate have high binding affinity to _
Tracheal tubes open to the external air found in arthropods.
Sytematic circulaton supplies the body with oxygen for _ respiration.
Gas exchange occurs directly across body surface of this organism.
In birds, gas exchanges occur along thin-walled spongy tubes called _
An organ that allows fish to breathe air from the surface of the water.
Gill structure that provides the most surface area.
Organisms from phylum _ use cutaneous respiration.