Eventually, I replaced it with a full-size tire, but I've always wondered why manufacturers say you shouldn't use the spare for longer than necessary. Since the spare tire is used so infrequently, carmakers have switched to narrow, compact spares to save space and weight. Of course, a spare tire is a lifesaver when regular tires go pop, but leaving the temporary tire on for longer than the manufacturer recommends invites a host of problems. First, a temporary spare isn't as durable as a normal tire.
Cells have become specialized and form true tissues and cnidarians are the first group to have B nerve cells organized into a nerve net B sense organs (statocysts and ocelli) B extracellular digestion Cnidarian Body Plan The diploblastic cnidarians are radially or biradially symmetrical with oral and aboral ends.
Confidence votes 1.2K. Cell specialization is when a group of cells work together by performing individual tasks for large organs and tissues. Actually, cell specialization is when cells specialize in certain duties, such as when blood cells carry nutrients, skin cells protect the interior of the body, etc. Specialized cells need to live off other cells because otherwise the specialized cell wouldn't exist. Each specialized cell is designed to carry out a special function, â¦ therefore we need many different specialized cells in order for the entire organism to survive.