Which of the following observations led mandel to conclude that some traits were recessive?

D

Explanation:

b is dominant over the allele for the white fur.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.