What is usefulness of science: Everything you need to know
Do you know that without science, the world today would not have been what it is. Technological advancement has completely changed the world. This has permanted into all spheres of our lives which include communications, Health, agriculture, building, etc. Exploration of the universe and improvements in conditions of living in our homes, schools, roads, etc.
Are all based on science in terms of modern equipment and materials. In fact, with the world changing very fast as a result of human activities and population growth, what may save our planet earth is scientific inquiry for solution to prevailing problems and those we may face in the future. Some biological research has been carried out by scientists leading to many discoveries in medicine, technology, agriculture and genetics.
Usefulness and Relevance of Biology
Biology forms the basis of disciplines like Human Medicine, Veterinary Medicine, Nursing, Agriculture, Forestry, Pharmacy, Food Technology, Laboratory Science Technology and Human Nutrition etc.
However, there is an aspect of biology which has been grossly misused by humans and which can have devastating effects and serious consequences. This is the development of biological weapons - the of deadly microbes to eliminate enemies. Although there is a global campaign against this, many countries still have large quantities of these weapons to protect themselves.
Living and Non-Living Things
All matter can be divided into either living or non-living things. Living things are different from non-living things by their ability to carry out the following functions which. are known as Life Processes. These processes are:
Nutrition:
All living things require food (feeding) without which they will die, and they vary in their mode of nutrition. They all need food as a source of energy for life processes. Living organisms that contain pigments including chlorophyll use light energy and carry out photosynthesis. These organisms include plants, algae and some bacteria.
Animals and fungi use chemical energy obtained from other living organisms (plants and animals) on which they feed.
Respiration:
Any life processes require energy which is released during the breakdown of energy-rich compounds in the cells. The energy released is stored in molecules of adenosine triphosphate (ATP) which occurs in all living things cells. This is the process where energy is made available to living things as a result of oxidation of food. This process involves the uptake of oxygen to release carbon dioxide and energy. Living things usually have parts of the body specialised for taking in oxygen, for instance human being use their lungs, fishes use their gills while plants use special openings in their leaves (stomata) or stems (lentices).
Growth:
This usually implies an increase in size and mass or increase in body complexity as a result of cell division and cell differentiation. With good feeding, a living organism increases its body mass.
Excretion:
This is the removal of waste products of metabolism from the body or cells which if not excreted will be harmful to the body.
Metabolism is the sum total of the chemical processes which take place within the cells or the body of the organisms. In other words, such activities lead to production of waste that is not useful to the body. Carbon dioxide is produced during respiration. This can be harmful to the body of it is in excess and so must be eliminated. Excess protein in the body cannot be stored. It is broken down and excreted as nitrogenous waste.
Reproduction:
This is the ability of living things to give rise to offsprings which have the same characteristics as their parents. Reproduction ensures the continuation of the species.
Movement:
Movement - This is a change in position which could be total, as in plants. Animals, or limited, as in plants. Animals generally move their whole bodies, and in most cases, with special locomotory organs like legs, wings, fins, etc. In most plants, movement is restricted to certain parts of the plant e.g. the opening and closing of petals or growth movements.
Irritability: (sensitivity)
This is the ability of an organism to respond to changes in both internal and external environment
(stimuli) to maximize its choices of survival. All living things are sensitive to their environments. In simple microscopic organisms like amoeba, sensitivity is simple, while in higher animals like man, highly coordinated sense organs and nervous systems have evolved and can respond to light, sound, smell, test, temperature etc. Plants, on the other hand, have no sense organs but respond in various ways to light, gravity, heat, chemicals, etc.
Difference between Living and Non-living things
Although there are exception, the differences between living and non-living things may be summarised as shown below:
Examples of living things
(a) Food is required to sustain life
(b) Growth is by the addition of new material from within as a result of food feeding, cell division and development
(c) Capable of reproduction
(d) Respiration is necessary
(e) Excretion is necessary
(f) Sensitive to external conditions
(g) Existence is rhythmic or periodic i.e living things live for sometime and then die.
Examples of non-living things
(a) No food is required
(b) Growth is by accretion i.e addition of new materials to their outside surface
(c) Incapable of reproduction
(d) No respiration is necessary
(e) No excretion is required
(f) Usually unaffected by external conditions
(g) It is inert. Non-living things don't die.
Differences between plants and Animals
All plants and animals are living things and they share similar characteristics, however, there are marked differences between them. These are shown in the table below:
Plants and Animals
All plants except saprophytic or parasitic ones manufacture their food. They use light energy absorbed by their chlorophyll (green pigment) and water and mineral salts absorbed from the soil by their roots. This process is called photosynthesis. In the process oxygen is produced as a waste product. This is autotrophic nutrition. Some autotrophic bacteria use energy obtained from the breakdown of some inorganic salts to manufacture their food. This is chemosynthesis.
Both photosynthetic and chemosynthetic organisms are autotrophs.
Examples of Animals
Animals on the other hand do not have chlorophyll, and so cannot manufacture their food. They depend on plants and other animals for their food. This is heterotrophs.
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