Concept Of Living Things
A things can be classified into two things, Living things and non-living things.
What distinguished living things from non-living are the type of characteristics they both exhibit.
Characteristics Of Living Things
We all know living things are things that can breath and exhibit some particular Characters.
No let look at the characteristics that living things exhibit.
These characteristics are classified into five characteristics.
[a] physiological character,
[b] genetic character,
[c] ecological character,
[d] structural character and,
[e] evolutionary character.top↑
[i] Reproduction: Living things can reproduce, that is they can give rise to young ones of their own kind.
NOTE: when defining reproduction don't use "given birth to young ones" because not every living things go through birth stage to produce. Use rise instead.
Note : The act of reproduction is what prevents creature from been extinct.
[ii] Nutrition: Nutrition is the process where food is taken in, digesting, absorbing and utilising food in living things.
Let explain this clearly:
Nutrition comprises four processes :
After taking in a particular food, the food will be broken down into simple molecules which will now be absorb by the body and then the body will make use of the absorb molecules by utilizing the absorb materials.
That is, Nutrition undergoes four sequence processes which are; taken in - digestion - absorbing- and utilising.
And also note: photosynthesis in plant is not a NUTRITION.
[iii] Excretion: Excretion is the removal of waste product of metabolism from inside the body E.g faeces. And living things do excrete.
[iv] Respiration: Respiration is the oxidative breaking down of complex food substances into simpler substances, such as glucose, in cells to release energy for vital activities.
[v] Movement: Movement is the activity which results in a change of position or shape of an organisms or part of it.
Every living things move.
[vi] Irritability: Irritability is the ability to perceive and respond to stimuli. Living things receive and respond to stimuli.
[vii] Growth: Living things Grow. Growth is irreversible increase in size or dry-weight as a result of synthesis of new body material, due to increase in number of cells and enlargement and differentiation of cells.top↑
Genetic Characteristics Of A Living Cell
[i] Each kind of living things has a constant number of chromosomes in each body cell.
[ii] Every living things transmit the characteristics of their species to the offspring through genes from the parents.
Ecological Characteristics Of A Living Cell
[i] Every kind of living organisms adapted to its own natural environment.
Structural Characteristics Of A Living Cell
[i] Each kind of living things has its own characteristic size and shape.
[ii] Each living things is made up of one or more cells.
Evolutionary Characteristics Of A Living Cell
[i] Each kind of living things has evolutionary relationship with other living things.top↑
[a] Non-living things do not feed, respire, excrete or reproduce.
[b] Non-living things cannot move by themselves, but can be moved by living things.
For example: Stone is a non-living things and it can be moved by man.
Or plant which cannot move by itself but can be move by animal [generally].
[c] If a non-living thing grows, it is by addition of similar material on the surface of existing material. Living things grows by using Nutrients, which are different from the body materials, to make new body materials.
Let use virus to explain the different between living things and non-living things.
Virus are microscopic organisms which show some characteristics of living things and as well as non-living things characters.
Note: All viruses are parasitic and causes diseases[pathogenic] e.g influenza.top↑
Structure Of A Virus
Virus structure contist of either ribose nucleic acid[RNA] or deoxyribose nucleic acid [DNA] located in a protein-lipid coat or protein.
Characteristics Of Living Things Shown By Viruses
[i] A virus grows and reproduces inside a host cell.
[ii] It has nucleic acid [ either DNA or RNA].
[iii] A virus also transmit characteristics from parent to offspring.
Characteristics Of Non-living Things Shown By Viruses
[i] Viruses cannot reproduce outside host cells.
[ii] A virus has no cytoplasm.
[iii] Viruses can be crystallized like salt and stored in that form.
[iv] A virus has no nucleus.
[v] Viruses does not respire or excrete or sensitivity.
I hope will all know the the difference between Living things and non-living things now. Our next topic will be on cell.top↑
please if the explanation is not clear enough, our tutors will be glad to explain more better. Use the ask questionfor any question.
Next Topic : The Cell Theory