Cross a yyll {heterogeneous parent with dominant) with yyll (homologous parent with recessive traits). look at the number of phenotypes u of the f1 generation. yyll x yy (parents, crosses will give you these offspring: yyll: 400 yyll: 100 yyll: 100 yyl

P:              YyLl                  x             yyll

G:        YL    Yl   yL  yl       x                    yl

F1: YyLl, Yyll, yyLl, yyll

G= 1:1:1:1

F= 1:1:1:1

            YL                   Yl                  yL              yl

yl        YyLl                Yyll                yyLl            yyll

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.