Abody part lost its original function through evolution what is the vocabulary term

The body parts which are present in reduced form in the body and have lost their function in the body because of evolution are called vestigial organs.

Explanation:

The vestigial or rudimentary organs are the remnants of the structures or organs which might have been large and functional in the ancestors, or the organisms from which the present-day organisms have evolved. These vestigial organs are often undersized, degenerated and non-functional.

1.Examples of vestigial organs in humans ( Figure 1)

2. Examples of vestigial organs in other animals (Figure 2)

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.