Chapter 1: The Living World

Ans:

• The classification of living organisms is done to make it easier to study the various living organisms as they have a huge diversity, which makes it difficult to study them. By classification, the various living organisms are placed into various categories based on their common characteristics. 

• Classification helps scientists and researchers to study them easily and in a systematic manner. The study of various living organisms will be beneficial for humankind as it will help in the discovery of various things, including new medicines and also the introduction of better-yielding varieties of crops. 

• With millions of species and various local names, confusion arises. Scientists use a standardised naming system to categorize and identify organisms worldwide to address this.

Ans: The classification systems change according to the need as they arise. There are millions of plants, animals, and microorganisms found on earth while several new species have been identified by scientists every now and then.

The world consists of huge numbers of species that are still left to be discovered. As they get discovered, they consist of new characters so they need to be classified by a new system of classification which needs to be prepared based on their characters. Thus, it results in the change in the previous system of classification leading to the formation of the new classification system.  

Ans: When we meet different people daily in our day-to-day life then we classify and categorize them based on various physical and characteristic features that include their level of education, their profession, their native place from where they belong, gender, physical features, etc.  

Ans: Following things we learn by identifying individuals and populations:

• Skin color

• Native place

• Sex

• Mother tongue

• Caste 

• Religion

• Food habit 

Ans:  Here, the Genus name is Mangifera, and the species name is indica which is always written in lowercase. Thus, the correct way to write the scientific name of Mango is Mangifera indica.

Ans: A taxon is the classification of the living beings that are arranged on the basis of a particular level of hierarchy.

The Following are the hierarchical levels arranged in descending order:

• Kingdom

• Phylum 

• Class 

• Order

• Family

• Genus

• Species

Ans: The correct sequence of taxonomic categories can be observed in the case of both (a) and (c) as the hierarchy includes Species, Genus, Family, Order, Phylum, and Kingdom that are arranged in an ascending manner. 

Ans: Species generally is a biological term that means the basic unit of classification. It is the group that consists of organisms that are similar in character and can undergo the process of inbreeding among themselves even in natural conditions and then result in the formation of fertile offspring.  Species are also found to be those organisms that have a similar gene pool as well. 

Ans: The definition of the following terms is:

(i) Phylum: Phylum refers to a taxonomic hierarchy or a taxon with one or more classes of organisms with similar characteristics. It comes below Kingdom and above Class

(ii) Class: The class is a group that consists of closely related orders. For example, the class Mammalia belongs to the orders Primata and Carnivora.

(iii) Family: Family is a group of individuals that are closely related genera. For example, Apes, Monkeys, and Man are related species that belong to the family Hominidae contains while in the case of plants, based on the vegetative and reproductive features the families are categorized.

(iv) Order: Order is composed of an individual that has closely related families. For example, Felidae and Canidae families are closely related and they belong to the order Carnivora.

(v) Genus: Genus includes the group of those species that are closely related to each other. Genus has more characteristics in common in comparison to species of other genera. For example, several species like nigrum, melongena, tuberosum, etc come under the genus Solanum.

Ans:

• The key is also known as the taxonomical strides or taxonomical aid that is used for the classification and identification of the various living organisms that are unknown. This will help the researchers to identify the organisms and then classify them. 

• A key is used by beginning with the first couplet and selecting the statement which fits the specimen. It directs the couplet to another couplet which provides the identity of the specimen. 

• For example, the presence or absence of hair on the body can give a clue if an animal belongs to mammals or not. Separate taxonomic keys are required for each taxonomic category such as family, genus, and species for the purpose of identification. There are three types of keys which are dichotomous, polyclave, and probability.