People breathe in oxygen molecules from the air and exhale carbon dioxide molecules. because of this, the air is full of carbon dioxide and oxygen mixed together. what is this an example of?

Refer to this portion of a dichotomous key to answer the question.1. (a) has a single dorsal fin  ®  5          (b) has a double dorsal fin  ®  25. (a) has a small fin on back near tail  ®  6          (b) has no fin on back near tail  ®  76. (a) has barbs near the mouth  ®  catfish          (b) does not have barbs near the mouth  ®  107. (a) tail is asymmetrical  ®  sturgeon      (b) tail is symmetrical  ®  8what would the result be when identifying a fish with a single dorsal fin, no fin on its back near the tail, and a tail that is asymmetrical? sturgeongo to step 8go tp step 2catfish.mark this and return