Code coverage means, how well your test set is covering your source code. i.e. to what extent is the source code covered by the set of Test cases. As mentioned in above answers, there are various coverage criteria, like paths, conditions, functions, statements, etc.
Chiasmus. Definition: Chiasmus is a specific type of parallelism. It consists of two parallel phrases in which corresponding words or phrases are placed in the opposite order.
Recombination can occur between any two chromatids within this tetrad structure. (The recombination process is discussed in greater detail later in this article.) Crossovers between homologous chromatids can be visualized in structures known as chiasmata, which appear late in prophase I (Figure 4).