Dichotomous keys are constructed based on-

a. combinations of characteristics in unknown organisms

b. combinations of characteristics known organisms

c. genetic sequences in known organisms

d. genetic sequences in unknown organisms

Answer;

B. combinations of characteristics in known organisms.

Explanation;

-A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish.

-A dichotomous key is a series statements consisting of 2 choices that describe characteristics of the unidentified organism. The user has to make a choice of which of the two statements best describes the unknown organism, then based on that choice moves to the next set of statements, ultimately ending in the identity of the unknown.

-Dichotomous keys are often used in field guides to help users accurately identify a plant or animal, but can be developed for virtually any object. They are particularly helpful when two species are very similar to one another.

i believe you meant to say air rather than hair so the answer is below ")

the dead sea, the lowest place on earth at 430 metres (1,410 ft) below sea level, has a correspondingly high typical atmospheric pressure of 1065 hpa.

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