Concept:
Analogy questions test the relationship between a profession/field of study and its subject matter.
• Ornithology: The scientific study of birds.
• Suffix "-logist": Refers to a person who studies or is an expert in a particular branch of knowledge.
Step 1: Analyzing the first pair.
An
Ornithologist is a scientist who specializes in
Birds.
The relationship is: [Expert] : [Subject of Study].
Step 2: Applying the relationship to the second pair.
An
Entomologist is a scientist who specializes in the study of
Insects.
(Note: "Herpetologist" studies reptiles, and "Botanist" studies plants).
Therefore, to complete the analogy, the missing word must be Insects.