The branch of Biology that deals with the principles of classification of organisms is known as

Step 1: Analyze the question The question asks for the branch of Biology that deals with the principles of classification of organisms, meaning how living things are grouped and arranged.

Step 2: Explain the concept

• Taxonomy is the science of identifying, naming, and classifying organisms into groups (taxa) based on their similarities and differences. It covers the principles and rules behind classification, from Kingdom down to Species.
• Nomenclature is only the naming of organisms (for example, the binomial system by Carolus Linnaeus, such as Homo sapiens). It is one part of taxonomy, not the whole of classification.
• Ecology is the study of the relationships between organisms and their environment.
• Biological index is not a recognised branch of Biology. It is a distractor.

Step 3: Solution by elimination

• A. Biological index: not a branch of Biology, so it is eliminated.
• B. Nomenclature: this deals with naming only, not the principles of classification, so it is eliminated.
• C. Taxonomy: this deals with classification principles, so it fits.
• D. Ecology: this is about organisms and their environment, so it is eliminated.

Step 4: Answer The correct option is C. taxonomy.

Tip: Remember "Taxi takes organisms to their correct groups." Taxonomy = grouping (classification), nomenclature = naming, ecology = environment. WASSCE often tests the difference between taxonomy and nomenclature, so keep that distinction clear.