Animal Classification
The animal kingdom is divided into two groups; invertebrates and vertebrates. This is called Classification. Vertebrates are animals that have a backbone and invertebrates are animals that don’t have a backbone. There are smaller groups that go inside of these two categories. The ones that go inside of the vertebrate category are mammals, reptiles, birds, fish and amphibians. The ones that go inside of the invertebrate’s category are annelids (earth worms), sponges, roundworms, flatworms, cnidarians (jelly fish), echinoderms (star fish), mollusks (snails) and arthropods (crustaceans, insects, arachnids and centipedes). Below is a picture of the animal kingdom:
Inside an Animal!
Every living organism is made out of cells. Cells are the smallest unit of life. A cell is made out of organelles. One cell is called unicellular, but many cells are called multicellular. When similar cells work together to perform a function, it's called a tissue eg. muscle tissue. An organ is a number of different tissues that work together. If organs work together they form a organ system, for example, Mouth - foodpipe - stomach - small intestine - large intestine.
The inside of an animal cell is filled with smaller substances which you can see in the picture below!
The inside of an animal cell is filled with smaller substances which you can see in the picture below!