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.

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.