Biology 10, Lesson 110 – Animal Structures and Patterns

In the animal world, different patterns and structures have been discovered, but they all follow the same “body plan” in one way or another.  Hox genes are responsible for these patterns.  These genes are a class of their own that encodes transcription factors during the development of an animal during their embryonic phase.  What kind of patterns have humans discovered in the animal kingdom?

Researchers have established that majority of animals follow two types of symmetry.  The first type is known as radial symmetry.  To fully understand this, imagine you have a stool and you cut it in half.  There is no way to tell which is the right side and which is the left side.  However, if you cut it through the middle, it would be obvious which is the top and which is the bottom.  This is radial symmetry.

The second type of symmetry is known as bilateral symmetry.  Animals that fall under this category have distinguishable front and back, top and bottom, but lack obvious signs of left and right.  Majority of the animals in the animal kingdom follow this kind of symmetry.

These patterns are formed by the Hox genes I mentioned earlier.  During the embryonic stage of an animal’s life, the Hox genes act as supervisors over where everything goes.  They make sure that the organs are put in the right order, then they create the other parts of the body like the head, the tail, etc.

As you can see, every animal follows some sort of pattern and structure.  The symmetry I described earlier are one of the characteristics scientists pay attention to when they are trying to categorize animals.

Thanks for reading!