2. What conclusions can you draw about the results of your second cross between a heterozygous red bull (Rr) and a heterozygous red cow (Rr)?

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems