Hey my friend did this one on Answer.com
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Whenever Mendel performed a cross with pea plants, he carefully categorized and counted the many offspring. Every time Mendel repeated a particular cross, obtained similar results. For example, whenever Mendel crossed two plants that were hybrid for stem height (Tt), about three fourths of the resulting plants were tall and about one fourth were short. Mendel realized that the principles of probability could be used to explain the results of genetic crosses.</span>
Answer:
Carbon dioxide and oxygen can't pass through the cuticle, but move in and out of leaves through openings called stomata
Explanation:
A dichotomous key is defined as a biological tool for identifying unknown organisms to a particular taxonomic level. It is constructed with many levels and series of couplets.
So, by observing the given dichotomous key, it is concluded that the correct answer is Option A- Organism X and Z have at least one observable trait in common in this dichotomous key.