All plants have a cell wall, all mammals have a cell membrane. a cell membrane is semi-permeable it allows mammal cells to absorb needed nutrients, oxygen and deposit waste into the blood stream where it is excreted through urine and feces. a plant cells nutrients are absorbed through the root system and leaves, waste is excreted in the form of oxygen through the plant itself.
<span>A plant's plastids contain its chlorophyll, which enables it to photosynthesize. If it lost the plastids, it would not be able to photosynthesize, which is the only way it can get food, so it would die.</span>
Classifying things by observation can best be done by using a : Taxon
Taxon divided organisms into different groups based on their unique similarities, which is the best way to classify things if you're doing it by observation.