Question

add a comma or semicolon if needed. otherwise, submit the text without any additional punctuation. hummingbirds dont have a sweet - taste receptor; sweetness due to a mutation in their umami taste receptors, but are still able to recognize nectars

Explanation:

The two parts of the sentence "Hummingbirds don't have a sweet - taste receptor" and "are still able to recognize nectar" are contrasting ideas. A semicolon can be used to separate two independent clauses that are closely related in thought. A comma alone would create a comma - splice error.

Answer:

Hummingbirds don't have a sweet - taste receptor; but are still able to recognize nectar's sweetness due to a mutation in their umami taste receptors.