The system of classification given by Linnoeus, classifies all living organisms into two main kingdom. Animals are normally distinguished by their movements, nutrition patterns of growth body organization etc. but there are a number of exceptions to all these characteristics.
For example, there are many not-green plants. They feed like animals e.g. muishrooms and other fungi grow on dead organic matter. Lichens can grow on the bank of a tree and even do not look to be alive. Sponges are fixed just like plants and have a branching pattern similar to plants. It also becomes difficult to classify unicellular organisms seen in a pond or lake to be called as plants or animals. They are colored green, yellow, brown or red. They are also photosynthetic like green plants. So this system of classification has the following shortcomings.
1. It is classifies prokaryotic cells and cukaryotic cells together in one group.
2. It has little regard for diversifies forms.
3. Photosynthetic green plants and non-photosynthetic plants are also grouped together.
4. It places unicelled organism which are so diversified in one group, i.e. protozoa.