What is the Living World ?
Simply put, the living world can be described as the world around us. It comprises all living creatures, plants and microorganisms that we cannot see. It has changed over the course of billions of years but the general composition has remained the same. The main components are still organic and inorganic matter. The organic matter includes amino acids, proteins, lipids etc. whereas inorganic matter includes water and minerals. The following is a brief summary of the world of the living that surrounds us. Living things show a lot of characteristics including growth and the ability to reproduce. Mammals are one of them. Living things live in a space nearer to the surface of the earth. This is because their activities are mostly operated by sunlight, water, carbon dioxide and oxygen. Their temperature range is fixed.
Essentials of the Living World
Basically, the essentials of living are its components. Below is a summary of all the components that are needed to sustain the world of the living.
Water: The water content of the human body is around 70-90%. It plays an integral role in sustaining different biological processes.
Oxygen: The earth’s atmosphere is made of 20% oxygen. It is required during aerobic respiration to produce energy that is important for different metabolic activities.
Sodium Chloride: Sodium chloride in its ionic form plays an important part in the metabolic process of the human body.
Proteins: Proteins are long chains of amino acids connected by peptide bonds. It plays a significant role in forming the structure of the organism. It can be broken down with the release of energy.
Lipids: These are alcohol and fatty acid polymers and they perform several functions.
Taxonomic Categories
To facilitate the study of kinds and diversity of organisms, biologists have developed certain rules and principles for the identification, nomenclature and classification of organisms.The science of naming and classifying organisms into groups is what we understand to be Taxonomy. It is useful in agriculture, forestry, industry and in general for knowing our bio-resources and their diversity. There are many categories/ranks and are generally referred to as taxonomic categories.
Characteristics of Living Organisms / Characteristics of Living Things
Growth - All living organisms grow in number and mass. A multicellular organism replicates by cell division. In plants, growth in the meristematic area continues throughout life and in animals, it occurs till a certain age. Living organisms show internal growth due to addition of important materials and reproduction of cells in the body. Non living organisms like mountains, boulders, crystals also show growth but this is because of the addition of similar materials to their outer surface. Growth is influenced by other factors too: the environment, the food that is being consumed and temperature play an important role too.
Reproduction - It is the formation of new individuals of the similar species. Reproduction is required for population and the survival of a race. In sexual reproduction two parents are involved to produce more or less similar organim, but in asexual reproduction, a single parent is involved and individual is the clone of the parent. Asexual reproduction may carry out by fermentation, fission, regeneration, vegetative propagation etc. In unicellular microorganism, growth and reproduction are the same. Numerous organisms such as mules, sterile worker bees, infertile human couples do not reproduce. Hence, reproduction is not an all-inclusive characteristic of all living organisms. However, no non-living object has the ability to replicate or reproduce.
Metabolism - The sum of all types of chemical reactions taking place in an individual because of specific interactions between different types of molecules in the interior of cells is called metabolism. All activities of an organism including growth, development, movements, reproduction etc. are due to metabolism. Metabolism can be classified into anabolism and catabolism. Anabolism comprises all the building up reactions that increase the mass of an organism like photosynthesis. Catabolism includes breakdown reactions, such as respiration, digestion etc.
Consciousness - It is the awareness of the surroundings and responding to external stimuli. External stimuli may be physical, chemical or biological. Plants also respond to stimuli like light, water, gravitation, pollution etc. All living organisms prokaryotic to eukaryotic respond to different kinds of stimuli. Human being is the only organism who is aware of himself. Consciousness plays an important role in determining behavioral patterns too. Consciousness therefore, becomes a defining property of all living things.
Homeostasis - In the world of living organisms, all living things have to maintain and control their internal states via homeostasis. This would involve balancing, temperature, internal pH levels and water levels. For example, the human body would adjust to the changes in the external weather by wearing a sweater or removing the clothing layers in the body so as to adjust their body temperature.
Life Span - every living organism has a definite life span of birth, growth, maturity, senescence and death. It differs from organism to organism and is related to a lot of external factors too.
Living organisms are therefore self-replicating, evolving and self-regulatory interactive systems capable of responding to external stimuli. Diversity in the living world or biodiversity is the occurrence of a wide range of life forms differing in physical features, size, colour, anatomy, habits and habitats. Each different type of microorganism, plant or animal represents a species. Patterns can be seen in a particular species.
Three-quarters of the land-based environment and roughly 66% of the ocean environment have been significantly altered. More than one third of the world's land surface and nearly more than half of freshwater resources are used for crop or livestock production, Climate change worsens the impact on nature, and our wellbeing. Humans have overfished the oceans, cleared forests, and polluted our water sources. They have created a climate crisis.
FAQs on The Living World
1. Write a note on Binomial Nomenclature.
It is the universally accepted principle to provide scientific names to known organisms. Each binomial name has two sections or components- the generic name (genus) and the specific epithet (species). This system of nomenclature was provided by Carolus Linnaeus.
The universal rules of nomenclature are as follows:
Biological names are written in italics and generally in Latin.
The first word in a biological or scientific name represents the genus while the second word represents the specific epithet.
When both words in a biological name are handwritten, they are separately underlined.
The first word that denotes the genus is written in capital and the specific epithet (species) starts with a small letter.
Classification - It is the process by which any organism or object or situation is grouped into convenient categories based on similar characteristics. Classification makes the study of organisms relatively convenient.
Taxonomy - It can be defined as the process of classification on the basis of internal and external structure along with the structure of the cell, the process of growth and development and ecological information.
2. Write a note on the Taxonomic Hierarchy.
The Taxonomic Hierarchy Follows the Below Categories
Species - Species are the natural population of individuals which resemble one another in all essential morphological and reproductive characteristics. They can interbreed freely and produce fertile offspring. For Humans, sapiens is a species of genus Homo.
Genus - Genus can be described as a group of related species which resemble one another in certain correlated characters. All species of a single genus are presumed to have evolved from a common ancestor. Tiger, lion, leopards are closely related species and therefore they are placed under the same genus Panther.
Family - Family is another taxonomic category that contains one or more related genera. All genera of a family have some common characteristics or features. For example, Family Solanaceae contains a number of genera like Datura, Withania etc
Order - This taxonomic category includes one or several related families. Families Canidae and Felidae are included in the same order of carnivores.
Class - A class is formed of one or several related orders. All dicots in plants come under the class Dicotyledoneae and they are grouped into many orders such as roales, polemoniales etc.
Division/Phylum - The term division is used for plants whilst phylum is used for animals. They are formed of one or many classes. The phylum chordate of animals contains not only the mammals but reptiles, amphibians and several others.
Kingdom - It is the highest taxonomic category. All animals belong to the kingdom Animalia, and all plants in the kingdom Plantae.
3. Why is metabolism needed in the living world?
Living organisms absorb energy from their surroundings and carry out their day to day activities. The enzyme conductive chemical reactions that take place in living organisms is called metabolism. These reactions are influenced by nutrients and solar energy. They convert into growth and are required for maintenance. The chemical reactions taking place in the living world are quite similar.
4. What are the characteristics of living things?
There are quite a few distinctive characteristics that determine living things:
Growth - Living things grow in size. Growth is determined by the different internal processes taking place. Growth is different in the case of plants and animals. Animals follow a certain growth pattern and plants continue to grow throughout their lifespan.
Reproduction - Reproduction is a process by which living organisms continue their species. Reproduction can be divided into two types- asexual and sexual.
Metabolism - The chemical reaction that occurs in living beings is called Metabolism. It takes place under two categories:
Anabolism - The synthesis
Catabolism - the breakdown.
Non-living beings don’t have metabolism.
Response to External Factors - Living organisms have a way of responding to heat, light and other factors. This feature ensures their survival.
5. Define diversity in the living world.
There are millions and billions of living organisms like plants, animals etc. Thousands and thousands are still unknown. Biologists have their own set of techniques for identification and describing them. They have a particular set of similarities and differences.
