Fig. 5.

Parity rule 2 plot analysis of eight red algae (GC bias on the x-axis and AT bias on that y-axis). The center point at 0.5 represents A = T and G = C, which means that there is no codon usage deviation between the two DNA strands. The red dots represent the high-bias genes, the blue dots represent the medium-bias genes, and the green dots represent the low-bias genes. A: unicellular red algal group; B: multicellular red algal group