Which statement is true?
A dichotomous key uses samples to identify organisms using observable traits.
A dichotomous key uses question pairs to identify organisms by their characteristics.
A dichotomous key uses question pairs to identify organisms by their group.
A dichotomous key uses photographs to identify organisms using observable traits.
A dichotomous key uses question pairs to identify organisms by their characteristics.
To determine which statement is true, we need to understand what a dichotomous key is and how it works.
A dichotomous key is a tool used by biologists to identify organisms based on their characteristics or traits. It consists of a series of carefully constructed questions or statements that are presented as pairs. Each question or statement offers two contrasting options or choices for the user to select from.
By going through the series of choices and selecting the appropriate option at each step, users can narrow down the possibilities and ultimately reach the identification of the organism they are trying to identify.
Now, let's evaluate each statement in light of this information:
1) "A dichotomous key uses samples to identify organisms using observable traits."
This statement is inaccurate. While a dichotomous key may rely on observable traits, it does not require the use of physical samples. Instead, it uses a series of questions or statements to guide the identification process.
2) "A dichotomous key uses question pairs to identify organisms by their characteristics."
This statement is the correct definition of a dichotomous key. It correctly describes how a dichotomous key operates, where questions are posed in pairs to guide the identification process based on the characteristics of the organism.
3) "A dichotomous key uses question pairs to identify organisms by their group."
This statement is incorrect. A dichotomous key is typically used to identify organisms based on their characteristics, not the groups to which they belong.
4) "A dichotomous key uses photographs to identify organisms using observable traits."
This statement is partially accurate. While photographs can be used as a visual aid to assist in the identification process, a dichotomous key primarily relies on the use of questions or statements, rather than photographs, to guide users.
In conclusion, the statement "A dichotomous key uses question pairs to identify organisms by their characteristics" is the true statement.