What does the large zigzagging arrow represent?

The process by which natural forces move weathered rock and soil brim one place to another is called

Matched chromosomes carrying information about the same characteristics in the organism are called

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