Question

What are the basic properties of living things? What arguments would you show to present that (a) a crystal, and (b) a candle flame are not alive and that a mango tree is alive?

Answer 1

The things that grow, undergo metabolism, show movement, and locomotion, produce their offspring through reproduction, have the ability to react, and sense their surroundings comes under the category of living beings.

Complete answer:
Growth, reproduction, ability to sense the environment, and suitable response against something all are counted as a unique feature of living organisms. Some features like metabolism, ability to self-replicate, self-organized interaction, and emergence can also be added to the list.
The characteristic of living organisms are given below -

1. All living organisms grow- increase in mass and number is the characteristic of growth. Multicellular organisms grow by cell division. By the process of cell division, the plants and unicellular organisms grow throughout their life. While the animals grow up to a certain age.
2. Metabolism- According to the function of the body and the organ, the chemicals convert themselves into some other biomolecules through certain metabolic reactions as the living organisms are composed of various chemicals. All plants, animals, and microbes exhibit metabolism.
3. Sensitivity- the living organisms whether prokaryotes or eukaryotes respond according to their surroundings and the stimuli present around them, it may be physical, chemical, or biological. Living organisms have the ability to sense their surroundings or environment and respond to these environmental stimuli which could be physical-chemical, biological, or even environmental.
4. Reproduction- Living organisms have the ability to produce their young ones by the process of reproduction.
5. Excretion- the removal of the waste products from the body of an organism.
6. Movement- The lining organisms show movement and locomotion and more specifically plants move according to the movement of the sun.
   A crystal and a candle flame do not show the above-mentioned properties while on the other hand, the mango tree shows growth, development, and reproduction by producing more trees through their seeds, they also show sensitivity towards the soil, sunlight, water, etc, Thus a mango tree is said to be alive.

Note:
All living organisms whether in the present, past, and future share a common ancestor along with similar genetic material up to some extent that is linked with one another. When a person is in a coma and is dependent upon the life-supporting machines which had become his heart and brain, then it is quite difficult to categorize the under living or non-living organisms.