The Living World – Introduction, Classification, Characteristics, FAQs

The living world has a wide range of its own. All living organisms grow and increase in mass and number of individuals. Growth, reproduction, ability to sense the environment and mount a suitable response is unique features of living organisms. Given below are some characteristic features of the Living world:

Characteristics of Living World

Respiration

• Aerobic respiration-Aerobic respiration is a chemical process in which oxygen is used to make energy from sugars. Aerobic respiration is also known as aerobic metabolism and cell respiration.
• Anaerobic respiration-Anaerobic respiration takes place in the absence of oxygen. examples include alcohol fermentation and lactic acid fermentation.

Nutrition

• Autotrophic -Autotrophic nutrition is a type of nutrition in which plants make their own food .they are interdependent on themselves. example- plants. Autotrophic nutrition is of two types: phototrophic, and chemotrophic.
• Heterotrophic – Heterotrophic nutrition is a type of nutrition in which an organism is dependent on another organism for food. example -humans. Heterotrophic nutrition is of three types: herbivorous, carnivorous, and omnivorous.

Excretion

A process of moving out waste material from the body is known as excretion.

Locomotion/Movement

Locomotion is a term used to describe a movement of an organism from one place to another.

Reproduction

• Asexual-In asexual reproduction, a single gamete is responsible for reproduction to take place i.e, new offspring is produced from a single parent. example-hydra and paramecium.
• Sexual-In sexual reproduction, both the gametes take part in reproduction. example – fishes, mammals.

Structural Organisation

• Unicellular-It is also known as a single-celled organism and only single cells perform all the functions needed for an organism to live. example- protozoa and Protista.
• Multicellular-Multicellular organisms consist of many cells to perform different functions. example-Dogs, cows.

Diversity

A large variety of anything is known as diversity. Diversity is a vast term to include different species, genes, and ecosystem levels. Thomas Lovejoy introduced the term biological diversity in 1980.

Biodiversity

A large variety of organisms or Terms used to refer to the number of varieties of plants and animals on earth is termed biodiversity. there are three types of biodiversity: genetic, species, and ecological diversity. There are over 15 Lakh species in the world of which 10 Lakh are animals(8 Lakh of insects and 2 Lakh of others) and 5 Lakh of plants.

Nomenclature

The scientific naming of organisms is known as nomenclature. Nomenclature is defined as the language of sculpture. The scientific name of mango is written as Mangifera indica.

Rules of Nomenclature

• Latinised names are used.
• The first word represents the genus and the second word is the species name.
• printed in italic, if handwritten then underline separately.
• The first word starts with a capital letter while the species name is written in small letter.

ICBN International Code of Botanical  Nomenclature (This is for giving scientific names to plants).

ICZN International Code of Zoological Nomenclature(This is for giving scientific names to animals).

Classification

Grouping organisms into categories on the basis of similarities and differences is known as classification. classification is the process by which anything is grouped into systematic categories based on some easily observable characters. for example, we easily recognize groups such as plants or animals, or Dogs or cats or insects.

Need for classification

To organize the vast number of plants and animals into categories that could be named, remembered, studied, and understood. classification avoids confusion among the different varieties of organisms. Moreover, it makes the study of organisms easier.

Given below are some scientist’s contributions to biology :

• Carolus Linneaus(Father of Taxonomy)-He gives the 2 kingdoms system.
• Hackel-  He gives the 3 kingdom systems.
• Copeland–He gives the 4 kingdom systems.
• R.H Whittaker-He gives the 5 kingdom system and is the popular one.
• Carl Woese-He gives the 6 kingdom system and is the latest.

Taxonomy

The study of principles and procedures of classification is termed taxonomy. Based on characteristics, all living organisms can be classified into different taxa. This process of classification is taxonomy.

Binomial Nomenclature

Binomial Nomenclature is given by  Carolous Linneaus. Each scientific name has two components – GENERIC NAME+SPECIFIC EPITHET.

Taxonomic Hierarchy

Arrangements of various steps (categories or taxa) of classification are termed a taxonomic hierarchy.

Ascending order of taxonomic categories showing hierarchical arrangement is species-genes-family-order-class-phylum-kingdom.

Herbarium

A herbarium is a place or a storehouse of flora from different regions of a country submitted in the form of a paper format sheet. it is a storehouse of collected plant specimens that are dried, pressed, and preserved on sheets.

Botanical Garden

The collection of living plants for reference is a botanical garden. In this various types of plants from different regions are collected which help not only in a scientific study but also for public knowledge regarding the common plants nearby them.

• Word’s First Botanical Garden- Royal Botanical Garden ENGLAND.
• India First Botanical Garden- Jim Corbett National Park, Uttarakhand(1935).

Museum

The museum is a collection of preserved plant and animal specimens. The museum has collections of preserved plant and animal specimens for study and reference.

Zoological Parks

A zoological park is a place where wild animals are kept in a protected environment under human care. example- Alipore zoo, Kolkata, West Bengal. Zoological parks are used for the maintenance of wild animals, and the reproduction of endangered species.

Key

Taxonomical aid is based on contrasting characters called couplets. The couplet has two opposite statements, each called to lead. separate keys for separate taxonomic categories needed. it is used to classify organisms.

Manual

The Manual has a description of species in an area. It is used for getting information for the identification of names. This is another means of recording descriptions. This also helps in correct identification.

Monograph

The monograph has information on any one taxon. It is used for classification purposes. A monograph is defined as a systematic detailed study of a particular organism or its taxonomic group.

Frequently Asked Questions

Question 1: Define The Following Terms-Phylum, Class, Family, Order, and Genus?

Answer:

Phylum- classes comprising animals like fishes, amphibians, reptiles, and birds along with mammals constitute the next higher category called phylum. All these, based on the common features like the presence of notochord and dorsal hollow neural system, are included in phylum Chordata.

Class- This category included related orders. for example- order primate comprising monkey, gorilla, and gibbon is placed in class Mammalia along with order Carnivora which includes animals like tiger, cat, and dog.

Family- Family has a group of genera with still less number of similarities as compared to genus and species.

Order- Order being a higher category is the assemblage of families which exhibit a few similar characters.

Genus- Genus comprises a group of related species which has more characters in common in comparison to species of other genera.

Question 2: How is a key helpful in the identification and classification of organisms?

Answer:

  Key is defined as the taxonomical aid used to identify and classify plants and animals based on the similarities and differences. keys are generally analytical in nature.

Question 3: Define a taxon.

Answer:

 Taxon is plural of taxa,it is the taxonomic unit of any rank. ARISTOTLE is known as the father of taxonomy.

Question 4: Why are living organisms classified?

Answer:

Living organism are classified due to the following reasons:

• to make study of organism easy.
• to avoid confusion.
• to learn the interrelationship among the various organisms.
• scientists classified living organism into different kingdoms,phylum,class,order,family,genus,species and are based on different criteria.

Question 5: write the scientific names of the following: Man, Housefly, Mango, and Wheat?

Answer:

1. Homo sapiens
2. Musca domestica
3. Mangifera indica
4. Triticum aestivum