Directions: Study the figure at left. What changes do you see? Fill in the correct answers.
a. What happened to the size of the horse?
b. The earliest horse had _________________ toes.
c. How many toes does a modern horse have?
d. What is it called?
I. The study of the parts, or structures, of living things is called anatomy. By studying the parts of living things, we can find out how closely related they are. For example, the bones of a bat's wing and a human hand are similar. This suggests the animals are related.
Directions: Carefully examine the drawings of the bones shown on page 4. Look for similarities among the various animals.
a. Color each part of the human arm a different color. (All bones of the wrist should be a single color. the bone groups of the hand should be a different single color.) Then color the corresponding bone in each of the other animals the same color as the human bone.
b. Describe the function of each set of bones below:
Animal
|
Function
|
human
|
|
whale
|
|
cat
|
|
bat
|
|
bird
|
|
crocodile
|
|
These structures are formed in similar ways during embryonic development and share like arrangements; however, they have somewhat different forms and functions.
On the outside, they look very different. However inside the bones are very similar. The bones are arranged in similar ways. They are called homologous structures.
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