Question

think back about your experience in this lab using a dichotomous key. what might make it hard for someone to use a dichotomous key? make a list of possible reasons.

Explanation:

A dichotomous key is a tool used to identify organisms or objects. Difficulties in using it can arise from unclear or ambiguous descriptions in the key. If the physical characteristics of the organism being identified are not distinct or are variable (e.g., due to environmental factors affecting appearance like a plant's leaf size varying with water availability), it can be hard to match to the key's criteria. Also, if the user has a lack of prior knowledge about the general structure or features of the group of organisms (e.g., not knowing basic parts of a flower when using a key for plant identification), misinterpretation of the key's questions (e.g., confusing "serrated" with "smooth" leaf edges due to poor vocabulary) can occur. Another issue could be damage to the organism (e.g., a broken insect wing missing a key identifying pattern) making it hard to apply the key's steps.

Answer:

• Unclear/ambiguous key descriptions.
• Variable or indistinct organism characteristics.
• Lack of prior knowledge about organism group.
• Misinterpretation of key vocabulary.
• Damage to the organism being identified.