DIGITAL TEXT BOOK

Submitted TO, Mr.Noushat. A. Salim Asst. Prof. In Natural Science Education KUCTE, Kulakkada

submitted By, Amrutha Raj B. Ed, Natural Science KUCTE, kulakkada

CONTENT SL. NO

CONTENT

PAGE. NO

1.

INTRODUCTION

1-4

2.

LET'S CLASSIFY AND LEARN

5-6

3.

TAXONOMIC KEY

6

4.

TAXONOMY

7 -8

5.

SCIENTISTS

9

6.

TAXONOMIC HIERARCHY PROPOSED BY CARL

10-12

WHY CLASSIFICATION?

Did you notice the opinion of the girl searching for a book? What are the advantages of arranging books in proper order? Haven't you noticed the arrangement of books in a library? In what all ways books may be arranged? Discuss. •  Things need to be classified first in order to arrange them properly.

Human beings shows a tendency to classify things around them. What are the bases for such classification?  Shape  Colour  Size  Use  Sound

Observe the figures

What criteria can be used for classifying these organisms?  Size  Beauty  Speed  Sharp incisors  Claws that can be withdrawn into the fe et  Which among these criteria is the most suitable one for classification? Why? Dis cu s s . If more criteria are adopted, classificatio n becomes more accurate.

LETS CLASSIFY AND LEARN Observe the illustration given below. DO you know all the peculiarities of the organisms shown in the illustration? Notice the classification of these organisms on the basis of certain observable characteristics. Analyse the criteria used for classification.

Why is the classification of these organisms very easy?  Less number of organisms  Specific indicators  Two clear options for each indicator

TAXONOMIC KEYS Taxonomic keys are the scientific indicators used for identifying and classifying plants and animals. One of the most important taxonomic keys is the dichotomous key. Each indicator in this key has two possibilities of selection. By choosing the peculiarities of the organisms to be identified and by proceeding systematically one can identify and classify the organisms.

TAXONOMY Taxonomy is the branch of biology that identifies organisms, classifies them on the basis of similarities and differences and names them scientifically. For the purpose of classification, the characteristic features of organisms, their external and internal features, genetic constitution, evolutionary relationship etc., are to be thoroughly studied. The study reveals the relation between various groups of organusms. It also enables us to acquire a general idea about the plants and animals of various geographical areas. More over taxonomy provides evidence that are helpful to explain the stages of evolution of organisms from the simple to the complex.

Based on similarities or dissimilarities, all organisms including human beings are placed in different levels of classification. It was a scientist named Carl Linneaus who fixed taxonomic hierarchy and provided a scientific base for classification. Hence he is known as the Father of Taxonomy.

Let's familiarise ourselves with some scientists who have made valuable contributions in the history of taxonomy.

TAXONOMIC HIERARCHY PROPOSED BY LINNEAUS

According to biological definition species are a group of organisms that can produce fertile offsprings through sexual reproduction. Species are the basic level of classification.Organism of a similar species costitutes the genus. Similar genus constitute the family and families join to form the order. Various order constitute class, related classes join to form phylum. All phyla constitute the kingdom, which is the highest level. Observe the illustration given below and discuss it on the basis of the indicators.Write down the inferences in the science diary.

INDICATORS 1. 2. 3. 4.

Which are the organisms included in kingdom Animalia? Which are the organisms excluded in each consicutive level? Why? At what levels of this illustrations can humans can be included? Complete the work sheet identify the level of classification of Cat