Compare and Contrast Plants and Humans as Living Organisms
By Gwennie Tan 10B
Living organisms are defined by the seven characteristics that they have to be capable of in order to be described as being ‘alive’. These are:
Movement – being able of controlled movement
Respiration – being able to gain energy
Sensitivity – being aware of their surroundings
Growth – being able to increase in size and mass
Reproduction – being able to produce offspring
Excretion – being able to get rid of toxic waste products
Nutrition – requiring food for energy
These characteristics can be easily remembered through the acronym MRS GREN. In addition to the seven characteristics mentioned above, there is also another characteristic that is not as well known by people – the ability to control their internal conditions.
Plants and humans (animals) are both classified as living organisms as they are able to fulfill the requirements above and although the two kingdoms are very different from each other, they still share similar traits and aspects such as:
* Cells and organelles
* Gas exchange
* Tissues, organs and organ system
Transport systems in both organisms rely on a medium, blood for animals and water for plants, and tubes in which the medium travel through. In plants, xylems are dead hollow cells with thick lignin-strengthened walls and small holes in their walls called pits which water enters/exits through. They transport water and dissolved minerals from the roots to the rest of the plant. Phloems are living cells controlled by adjacent companion cells. They contain perforated sieve plates and transport glucose and amino acids from the leaves to other parts of the plant. The two tubes together are called a vascular bundle with the phloem layer facing outwards in a stem.
On the other hand, humans have a double.