Final answer:
A serrated utility knife is a knife with a straight blade and bumpy ridges, making it perfect for slicing through tough textures like the skin of an avocado or a french baguette.
Step-by-step explanation:
The knife that can be described as having a straight blade with bumpy ridges, making it perfect for slicing through tough textures like the skin of an avocado or a french baguette, is a serrated utility knife. The bumpy ridges on the blade, known as serrations, help grip the surface of the food and provide better control when cutting through tough textures. The serrated utility knife is commonly used for slicing bread, tomatoes, and other foods with tough exteriors.