A sorting device that is useful in classifying by observation is a <u>key</u>.
<h3><u>Explanation</u>;</h3>
<em><u>Classification key or taxonomic key is a device that is used by scientists to identify unknown organisms. </u></em>
They are constructed so that the user gets a series of choices about the characteristics of the unknown organisms.Thus, by making the correct choice at each step, one is led to the identity of the specimen.
Therefore<u><em>, keys can be used to identify a living organism or determine which group it belongs to</em></u> by answering questions on the key about characteristics of living things.
Answer: Reproductive problems from imbalanced hormones can occur when abnormal levels of estrogen and androgen sex hormones develop, and can cause infertility and other health issues.
