Living things and cells

Question

1. Living things are made up of cells and some living things are cells. Justify.
2. All cells have similar chemical composition which may differ with need to specialize. Explain how the above statement is applicable to living systems.

Answer 1

Hello Masika. Here is an answer to your queries.

1. Living things are defined based not only on their anatomy but largely based on their physiology. Specifically, they should possess the ability to grow, obtain and use energy, homeostasis, and reproduce. Some organisms are single-celled such as some bacteria and protozoa. Since these cells accomplish all characteristics of living organisms, they, therefore, assert that some living things are cells. Another example, though hotly debated among experts, is that of viruses. While inert in external environments to the point of being questioned as viable living things, they are also cells.
2. One distinct aspect of living systems is that the life forms within interact with their environment and self-organize based on that interaction. Self-organization in this case may be regarded as the quintessential of adaptation. Similar chemical compositions such as water as a solvent and medium of chemical reactions, and energy storage as proteins and carbohydrates do not mean that those compositions are of the same levels in all cells. An example would be an organism that adapts to run from predators and has to develop muscles equipped for sprinting or better respiration. Such muscle cells would develop proteins for rapid contraction, nerve cells for better transmission of signals, and red blood cells with high protein hemoglobin levels for better oxygenation. That organism would essentially be self-organizing to fit in that living system as it interacts with the environment containing predators, food and other climatic factors.