The one-seed fruit in which the pericarp and seed coat have become fused together is...

Explanation

In Biology, fruits can be classified into different types based on their characteristics. One-seed fruit is a type of fruit that has only one seed within it. In some cases, the pericarp (the outer layer of the fruit) and seed coat (the protective layer covering the seed) may fuse together to form a single structure. This type of fruit is known as a caryopsis. The question is asking which of the given options is the correct name for a one-seed fruit in which the pericarp and seed coat have become fused together. Based on the options, the correct answer is Option D, caryopsis. It is important to note that other types of fruits exist, such as drupes, legumes, samaras, and achene. These fruits differ in their characteristics and can be identified by their unique features. For example, a drupe is a fruit that has a fleshy outer layer and a hard inner layer surrounding the seed, while a legume is a fruit that splits open along two sides to release seeds. Overall, caryopses are one-seed fruits in which the pericarp and seed coat have become fused together, and are commonly found in grasses such as corn and wheat.