Topic Content:
- Characteristics of Living Things
Living things are those things that carry out the activities of life, and these activities distinguish living things from non-living things.
All living organisms share several key characteristics or functions which include, movement, sensitivity, or response to the environment called irritability, reproduction, respiration, growth and development, excretion, death, nutrition, etc.
Let’s discuss some of these characteristics;
1. Movement:
This is the ability of an organism to move its whole body, or parts of its body, from one place to another. Living things like animals can move from place to place in search of food. They have organs for movement, for example, legs, limbs, flagella, cilia, etc. Movement is in several forms like flying, crawling, walking, swimming, jumping, etc.
Plants move parts of their body mainly in response to stimuli.
A stimulus is something that provokes or causes an action or response.
The roots move down in response to gravity and water, while the shoots move towards sunlight for photosynthesisPhotosynthesis is the process by which green plants, and some algae and bacteria, convert the energy of sunlight into chemical energy. This energy is then used to synthesize carbohydrates such as... More.
2. Feeding or Nutrition:
This is the ability of living organisms to feed and give energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit... More. Plants manufacture their own food, through a process called photosynthesis, while animals feed on plants and other animals.
3. Growth:
Growth is an irreversible increase in the size of an organism.
4. Irritability:
This is the ability of living organisms to respond to changes in the environment. These changes are called stimuli. Plants bend towards sunlight, water, gravity, and sometimes when touched.
Some examples of stimuli living things react to are light, sound, temperature, touch, and pressure. For example, if you walk outside on a very sunny day, your pupils will constrict to protect your eyes from taking in too much light.
5. Respiration:
All organisms require oxygen to break down food to release energy. This is called respiration. They also take in oxygen and give out carbon dioxide by a process called breathing. Plants, however, in the presence of sunlight, take in carbon dioxide and give out oxygen, during photosynthesis.
6. Excretion:
This is the release of metabolic wasteMetabolic wastes are the substances leftover from metabolic processes (like cellular respiration) which are not absorbed by the organism and hence they should be excreted. Metabolic wastes can be categorized into... More products from the bodies of living organisms. Animals remove excess water, carbon dioxide and other harmful materials in the form of sweat, faeces and urine, while plants remove oxygen, water, gun, etc.
7. Reproduction:
This is the ability of living organisms to give rise to new individuals of the same species, to ensure continuity of life.
8. Death:
All living things die.