Mongols Ovoo Biology tech effect Cavalry hit points 30%.But if you learn nomal Biology first，the tech will become 1.0×1.2×1.1=1.32 .For example Elite Mangudai should be 156hp if you Learn Ovoo Biology tech（120×1.3）.But if you try learn nomal than the Ovoo tech.The health will became 162(120×1.2×1.1)
Please forgive me for my poor English
Thanks @Suotan6962! There should be a fix coming for Biology. Much appreciated!