<P> The presence, frequency and identification of substructures using an electron microscope has led to further classification, dividing chromoplasts into five main categories: Globular chromoplasts, crystalline chromoplasts, fibrillar chromoplasts, tubular chromoplasts and membranous chromoplasts . It has also been found that different types of chromoplasts can coexist in the same organ . Some examples of plants in the various categories include mangos, which have globular chromoplasts, and carrots which have crystalline chromoplasts . </P> <P> Although some chromoplasts are easily categorized, others have characteristics from multiple categories that make them hard to place . Tomatoes accumulate carotenoids, mainly lycopene crystalloids in membrane - shaped structures, which could place them in either the crystalline or membranous category . </P> <P> Plastids are descendants of cyanobacteria, photosynthetic prokaryotes, which integrated themselves into the eukaryotic ancestor of algæ and plants, forming an endosymbiotic relationship . The ancestors of plastids diversified into a variety of plastid types, including chromoplasts . Plastids also possess their own small genome and some have the ability to produce a percentage of their own proteins . </P> <P> The main evolutionary purpose of chromoplasts is to attract animals and insects to pollinate their flowers and disperse their seeds . The bright colors often produced by chromoplasts is one of many ways to achieve this . Many plants have evolved symbiotic relationships with a single pollinator . Color can be a very important factor in determining which pollinators visit a flower, as specific colors attract specific pollinators . White flowers tend to attract beetles, bees are most often attracted to violet and blue flowers, and butterflies are often attracted to warmer colors like yellows and oranges . </P>

Where are the chromoplasts located in the cell