Chapter 17, Problem 3A

Summary Introduction

To analyze:

The correct term to describe the given sentence.

Introduction:

As there are about 1.7 million of species known and it is impossible to study each of them individually, so need for classification was aroused. Classification is grouping of objects or organisms based on a set of criteria. Classification is essential because it permits scientists to identify, group, and properly name organisms through a standardized system.

Answer to Problem 3A

The correct term to describe Branch of biology that groups and names species based on studies of their different characteristics is “Taxonomy”.

Explanation of Solution

The word “Taxonomy” is derived from a Greek word “taxis”, meaning arrangement or division, and “nomos”, meaning method.Taxonomy can be defined as thebranch of Biology that deals with the process of classifying different living species. A taxon is referred to as a group of organisms classified as a unit.

Taxonomic hierarchy denotes to the arrangement of categories in increasing or decreasing order. Kingdom is the highest rank and species is the lowest rank in the taxonomic hierarchy. In the taxonomic hierarchy, the biological classification of living beings is divided into 7 levels of taxonomy which are Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Kingdom: The taxon composed of related phyla or divison is a kingdom. A kingdom is the highest level of classification, which is divided into subgroups at various levels. There are 5 kingdoms in which the living organisms are classified, namely, Animalia, Plantae, Fungi, Protista, and Monera.

Phylum: This is the next level of classification and is more specific than the kingdom. A phylum or division contains related classes.

Class: This was the most general rank in the taxonomic hierarchy till phyla were not familiarized. Kingdom Animalia includes 108 classes together with class mammalia, reptilia, aves. However, the classes used nowadays are different from those proposed by Linnaeus and are not used often.

Order: Order is a more specific rank than class. The order constitutes one or more than one similar family. There are around 26 orders in class mammalia such as primates, carnivora.

Family: This category of taxonomic hierarchy includes various similar related genera that share a few similarities. For example, the families in the order Carnivora include Canidae, Felidae, Ursidae.

Genus: A group of similar species that share common ancestor forms a genus. Some genera have only one species and are known as monotypic, whereas, some have more than one species and is known as polytypic. For example, lion and tiger are placed under the genus Panthera.

Species: It is the lowest level of taxonomic hierarchy. There are about 8.7 million different species on earth. It refers to a group of organisms that are similar in shape, form, reproductive features and can interbreed to produce fertile offsprings. Species can be further divided into sub-species.