Introduction:

In this article, Several natural characters defining living beings we are going to learn about natural characters such as growth, metabolism, reproduction, cellular organization, are showed by living beings. We will discuss the defining properties of the living beings.

several characters of living beings

we will start with our first character, which is:

 Description of Several natural characters defining living beings:

  • Growth– increase in number and increase in mass are twin characters of growth. In the living beings, growth is due to vital activities (metabolism).

*Metabolism is sum total of all the chemical reactions occurring inside the body.

Growth is a characteristic feature of the living being but not a defining property because some non-living objects like mountains and sand-dunes also grow but they represent only extrinsic growth.

So, only internal growth is included among the Several natural characters defining living beings.

  • Reproduction– It is a phenomenon which compensates the loss of life due to natural death. Or it can be defined as the formation of similar types of individuals to maintain life continuity.

There are 2 different ways used by livings beings to reproduce:-

  1. Sexual reproduction- *It may be uniparental or biparental.                                                                                            *Gametogenesis and Syngamy are the 2 essential steps.                                                *It is a slow, complex and elaborate process.                                                                          *Variations are found here.
  2. Asexual reproduction- *It is always uniparental and forming individuals are genetically identical to parents, this one occurs with the help of the following structures.                                                                                                                                                                                                    *It is comparatively a fast and simple process.

Types of asexual reproduction with names of the living beings using them-

a): BUDDING- Hydra and Yeast

b): BINARY FISSION- Amoeba/Diatoms/Euglenoids

c): FRAGMENTATION- Filamentous organism such as (fungi, ulothrix, spirogyra, moss protonema)

d): TRUE-REGENERATION: Planaria

e): REGENERATION: Lizard

f): SPORE(Mitospore): types of spores-

1. Sporangiospore: characteristics of these spores- are endogenous

and zoospores are motile and aplanospre are non motile

sporangiospore

2. Conidia: characters of these spores- are exogenous always and non-motile and basipetal.

asexual reproduction in conidia

3. Chlamydospore: characteristics of these spores- are thickly walled having perennating structure.

chlamydiospore

So, reproduction is one of those Several natural characters defining living beings.

  • Metabolism: Metabolism is defined as the vital activities of a living being.

  •   *Metabolism reactions can be demonstrated outside the body.

  • *Invitro metabolic reactions are the living reactions but not living beings.

Anabolism and Catabolism are combinely known as Metabolism.

Anabolism > Catabolism= Growth

Anabolism < Catabolism= Degrowth

Anabolism = Catabolism= No growth

Small cell        ←←←   Large cell                                                                                                                                                                                                                                                   ↓                                                ↓

          Less cytoplasm     ←←←    More cytoplasm

↓                                                     ↓                                                                                                         More KI(karyoplasmic index)←←←Less KI(karyoplasmic index)

↓                                                      ↓

More active               ←←←                  Less active

#Karyoplasmic index: karyoplasmic index also known as the nucleocytoplasmic ratio or surface area to volume ratio⇒

{Vn⁄∑Vc-Vn = Vn/Vc }

Vn = volume of the nucleus

Vc = volume of cytoplasm

 

  • Cellular Organisation: the cell is the smallest structural, functional and genetical unit of life which can freely divide
  • level of organisation in living beings

{Chemical hierarchy   → Biological hierarchy    → ecological hierarchy}

In chemical hierarchy:

electron/proton/neutron

atom

molecule

compound

complex compound

biomolecule

In biological hierarchy:

cell

tissues

tissues system

organ

organ system

organism

In ecological hierarchy:

organism

population

community

ecosystem

biome

biosphere

ecologiacl hierarchy

  • Consciousness: All living beings can respond to the changes in their surroundings.

It is due to contractibility and irritability of protoplasm, from prokaryotes to eukaryotes all have consciousness but self-consciousness is found only in human beings because of a developed CNS(central nervous system) and communication skills.

And individual in the coma is living on the basis of cellular structure and metabolism but consciousness is absent, he/she is temporary out of the living phase.

Another example of consciousness is seasonal breeders and photoperiodism in plants.

NOTE- In the cellular organism, growth and reproduction are mutually inclusive events, means they are the synonym of each other but for the multicellular organism, growth and reproduction are mutually exclusive events.

The conclusion of several natural characters of living beings:

Now we will conclude what we learned in today’s article.

we learned about several characters such as growth, reproduction, metabolism, etc. which are defining properties of living beings. we learned about the karyoplasmic ratio.

 

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