In Bowen's Reaction Series, which mineral crystallizes last in the discontinuous series?

In Bowen's Reaction Series, biotite is the mineral that crystallizes last in the discontinuous series. The series outlines the order in which minerals crystallize from a cooling magma, based on their melting points and chemical composition.

Initially, higher-temperature minerals such as olivine and pyroxene crystallize, followed by amphibole and then biotite. This order is significant because it highlights the progressive changes in chemical composition of the melt as it cools, leading to the formation of minerals with increasingly complex structures.

Biotite, being a mica, has a relatively low crystallization temperature within the discontinuous series and forms after the earlier minerals have already crystallized. Understanding the sequence in which these minerals crystallize is essential for geological studies, as it reveals information about the conditions under which the igneous rock was formed.

The other choices such as olivine, granite, and feldspar do not crystallize at the same stage as biotite in this particular sequence, making biotite the correct and definitive answer to the question.