The genetic combination of their parents.
The Serratus anterior in man is homologous to the Serratus ventralis muscle in the cat. The Serratus anterior is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and insects along the entire anterior length of the medial border of the scapula. The Serratus anterior acts to pull the scapula forward around the thorax. Serratus ventralis in the cats looks like fingers because it attaches to the ribs, but has nothing to attach to between the ribs.
Answer:
one motor neuron
Explanation:
Although a single motor neuron can innervate several muscle fibers, each muscle fiber is innervated by only one motor neuron
