Sometimes the form or appearance of an organism is studied to determine a taxon. The scientist is using _.

The correct answer would be - Morphology.

Explanation:

Morphology is one of the biology disciplines that includes the study of the physical structure, form, and shape of individual groups of organisms such as hair color, eye color, shape and other morphological characters.

Morphological study or morphology only focuses n the physical traits instead of the function or roles of the traits. Determining or classifying the organisms in the taxonomic hierarchy on the basis is known as morphological classification.

Thus, the correct answer is - Morphology.

Morphology Should be the correct answer