Similar structures that are inherited from a common ancestor are called analogous structures.
a. true
b. false

b. False

Explanation:

Similar structures are similar structures in unrelated organisms. The structures are similar because they evolved to do the same job, not because they were inherited from a common ancestor. For example, the wings of birds and bats look similar on the outside. They also have the same function. However, the wings evolved independently in the two groups of animals. This is evident when comparing the pattern of bones inside the wings.

Homologous structures are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in descendants. A clear example is the hands of several different mammals. They all have the same basic bone pattern. They inherited this pattern from a common ancestor. However, their forelimbs now have different functions.

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.