7. What is the main difference between the body plan of ticks and that of insects?

Ticks may look like insects but there are distinct differences in their bodies that puts them in the arachnid family. First, is that they have four pairs of legs, so eight total. Insects only have six legs. Second, insects have three body segments, while ticks don't have any (spiders have two body segments).

Explanation:

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.