Video Transcript
Horses have been used throughout
human history to work on farms, pulling heavy machinery, and to transport people and
goods. Which of the following structural
adaptations is the most useful for a horse to carry out these roles? (A) Many blunt teeth. (B) Thick, brown fur. (C) Strong, powerful legs. (D) Long eyelashes. Or (E) clean, glossy coat.
This question asks us about a
structural adaptation. A structural adaptation is a
physical characteristic of an organism that makes it well suited to its
environment. In this case, the question is
asking us about a structural adaptation that is also useful for the roles that
horses fill for humans. Those roles include working on
farms, pulling heavy machinery, and transporting people and goods. All of these roles relate to moving
heavy things, such as machines or people. So, the structural adaptation that
would be most useful for this would relate to the strength to carry or pull
things.
The answer choices list several
physical characteristics of horses. All of these are structural
adaptations of the horse in their own way. However, the only choice that
relates to the horse’s physical strength to carry and pull things is (C). Using its strong, powerful legs,
the horse can carry and pull a lot of weight, which makes it useful to humans as a
work animal.
Therefore, the correct answer to
this question is (C). The structural adaptation of a
horse that is most useful to it carrying out its roles as a work animal for humans
is its strong, powerful legs.
