Animals are generally classified as vertebrates and invertebrates. Animals with a backbone are known as vertebrates and those without a backbone are invertebrates. Some example of vertebrates are human beings, cattle, lions, etc. Some examples of invertebrates include worms, snails, bees, etc. The vertebrates contain a skeleton of bones that include a spinal column and generally tend to grow larger in size. The lack of a backbone in invertebrates often means they are incapable of growing to larger sizes. Interestingly, even with these advantages, vertebrates make up for only about 2% of all the known animal species, invertebrates make up for the rest. Vertebrates are classified into 5 major classes: fish, amphibians, reptiles, mammals and birds.
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