Final answer:
The type of adaptation not recognized in biology is 'Mechanical', and slight differences in inherited traits are known as 'Variations'.
Step-by-step explanation:
The type of adaptation that is not listed among recognized biological categories is Mechanical. In biology, the recognized types of adaptations are Structural, Behavioral, and Functional. Thus, the correct answer to the first part of the question is 'B. Mechanical'.
Slight differences in inherited traits, such as feather color in birds, are called Variations. These variations can sometimes lead to adaptations if they provide some advantage in survival or reproduction within a particular environment. Consequently, the correct answer to the second part of the question is 'C. Variations'.
An adaptation is a heritable trait that aids the survival and reproduction of an organism in its present environment. The types of adaptations include structural, mechanical, behavioral, and functional adaptations. Therefore, the correct answer is D. Functional.
Slight differences in inherited traits, such as feather color in birds, are called adaptations.