Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification?

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Kerala State Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification?

Why Classification? Textbook Questions and Answers

Classification

Classification is the grouping of organisms on the basis of similarities and differences. Classification using suitable criteria makes the study of organisms more easy. Many criteria are used in classification.
Eg: size, beauty, speed, type of teeth, claws, etc.

Taxonomic Keys

Scientific indicators used to recognize and classify plants and animals are called Taxonomic keys. Dichotomous keys is the most popular among these. Each indicator contains 2 options for selection. By selecting the characteristic feature of the organism to be identified it can be recognized and classified.

Indicators (Text Book Page No: 170)

Why Classification Question 1.
Peculiarity of dichotomous keys
Answer:
Dichotomous key is the most popular among these. Each indicator contains 2 options for selection. By selecting the characteristic feature of the organism to be identified it can be recognized and classified.

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Taxonomy

Taxonomy is the branch of science that deals with the identification and classification of organisms according to similarities and differences. Organisms are given scientific names. Carl Linnaeus laid foundation stone for classification. In all organism that including human beings are placed in different levels of classification. It was scientist named carl Linnaeus who fixed taxonomic hierarchy and provided a scientific base for classification. Hence he is known as the father of taxonomy.

Scientists and their Contribution to Taxonomy

Aristotle:
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 1
Father of Biology Classified animals as red-blooded and non-red blooded

Theophrastus:
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 2
Father of Botany Grouped Plants as animals, biennials, and perennials

Charaka:
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 3
Father of Ayurveda Author of ‘Charaka Samhita’

John Ray:
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 4
– Used the term ‘Species’ for the first time
– Recorded more than 18000 plants in his book ‘Historia Generalis Plantarum’

Carls Linnaeus:
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 5
– Father of Modern Taxonomy.
– Suggested different levels of Classification
– Introduced Binomial Nomenclature

Indicators (Text Book Page No: 173)

Circumstances that Led to the formulation of Six Kingdom Classification Question 2. Which are the organisms included in kingdom Animalia?
Answer:
Cockroach, Butterfly, Bird, Rabbit, Cat, Tiger, Lion, bear

Basic Science for Class 8 Chapter 12 Question 3.
Which organisms are excluded at each consecutive level? Why?
Answer:

  • Eliminated from Phylum Chordates — Butterfly, Cockroach
    Reason — Animals with vertebral columns alone are included in the phylum chordates.
  • Eliminated from Class Mammalia
    — Bird (Pigeon) Reason — Animals that give birth to young ones alone included in this group.
  • Eliminated from the order Carnivora — Rabbit
    Reason — Carnivores alone included in this order.
  • Eliminated from the family Felidae — Bear
    Reason — It does not have retractile claws.
  • Eliminated from the Genus Felis — Lion, tiger
    Reason — Animals having small body and without roaring sound are included.
  • Eliminated from the Species domestic — Wild Cat
    Reason — It has the basic features of cat

Which Two Kingdoms did Linnaeus Recognize Question 4.
At what levels of this illustration can humans be included?
Answer:
Man can be included in Class Mam-malia and Phylum Chordata.

Binomial Nomenclature

Binomial nomenclature is the scientific naming of organisms. Scientific name consists of two words. First word indicates genus and second word indicates species. Scientific name of man – Homo sapiens. Earlier two-kingdom classification was in practice. Accordingly, the organisms were broadly classified into planate and anemia. Later Rober. H. Whittaker classified organisms into 5 Kingdoms.
Eg : Monera, Protista, Fungi, Plantae, Animalia.
Another Scientist Carl Vaus added ‘domain’ above kingdom and expanded it into 6 kingdom classification.

Indicators (Text Book Page No: 176)

8 Kingdom Classification Question 5.
Limitations of two-kingdom classification.
Answer:
Bacteria, Fungus, etc were not inclu­ded in two kingdom classification.

Basic Science Solution Question 6.
Possibilities of five kingdom classification.
Answer:
In five kingdom classification bacteri­a, amoeba, fungus, plants, and animals were included in separate kingdoms according to their characteristics.

HSSlive Answer Key Question 7.
Circumstances that led to the formulation of six kingdom classification.
Answer:
In ancient times knowledge regarding the characteristics of micro organ­isms was limited. It was found out that the cell structu­re and physiology of archaebacteria belongs to kingdom monera are quite different from other bacteria. Hence kingdom monera was divided into two kingdoms – Archae and Bacteria. Be­sides another level namely ‘domain’ was added above kingdom. Thus 6 king­dom classification came into existence

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Classification of Science Question 4.
Completing the table (Text Book Page No: 177)
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 6
Answer:

Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Primates
Family Hominidae
Genus Homo
Species Sapiens

Indicators (Text Book Page No: 178)

Classification of Words: Odd Man Out Question 8.
What are the peculiarities of virus?
Answer:
Viruses have no specific cell structure. Genetic material and a protein sheath alone are present. It is difficult to destroy them. They live only in living cells. They are dead or inactive outside the cell. It multiplies inside the host cell and destroys it.

Question 9.
Can virus be included in any of the classification methods we have discussed earlier? Why?
Answer:
As viruses have no cellular structure, it is not possible to include in any of the classifications mentioned.

Let US assess (Text Book Page No: 179) 

Question 10.
Identify the word pair relation and fill in the blanks
a. Five kingdom classification: Robert H.Whittaker
Six kingdom classification :
b. Charaka: Charaka Samhita
John Ray
Answer:
a. Carl Vaus
b. Historia Generalis Plantarum

Question 11.
Hints about some organisms are given below. Name the
kingdom to which these organisms belong:
a. Multicellular heterotrophic organisms with a nucleus and capacity for locomotion.
b. Multicellular, heterotrophic, non-motile organisms with a nucleus.
c. Unicellular organisms with a nucleus.
d. Multicellular, autotrophic, non-motile organisms with a nucleus.
Answer:
a. Animals
b. Fungi
c. Amoeba
d.Plants

Question 12.
Write from the table the name of the organism which has more resemblances with tiger. Give explanations for your answer.
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 7
Answer:
Lion having the scientific name Pantheraleo.
Lion and Tiger belongs to same Genus ‘Panthera’

Why Classification? Additional Questions and Answers

Question 13.
Identify the word pair relation and fill the blanks.
a. 2 Kingdom Classification: Carls Linnaeus:: 5 kingdom Classification: …………….
b.Mushrooms: Fungi:: Bacteria: ……………..
c. Aristotle – Father of Biology Carls Linnaeus – …………….
d. Golden shower: Cassia fistula::…………..: Corvus splendens
e. Charaka: Father of Ayurveda::……………: Father of Botany
Answer:
a. R H Whittaker
b. Monera
c. Father of Taxonomy
d. Crow
e. Theophrastus

Question 14.
2. Identify the odd one and write the characteristic features of others.
a. Lion, Tiger, Rabbit, Cat.
b. Genus, Order, Carl Linnaeus, Phylum.
Answer:
a. Rabbit – Others including order Carnivora
b. Carl Linnaeus – He is the Father of Modern Taxonomy. Others are different levels of classification.

Question 15.
Which organism is most suit¬able for the following indicators (amoeba, bacteria, virus, Fungus)
1. Lives only in living cell
2. Pathogen
3. Only genetic material and a protein covering.
Answer:
Virus

Question 16.
Find out the scientists suitable to the statements given.
i. Author of Charaka Samhitha
ii. Author of Historia Generalis Plantarum
iii. Father of Modern Taxonomy
iv.Father of Biology
Answer:
i. Charaka
ii. John ray
iii. Carl Linnaeus
iv. Aristotle

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Question 5.
Complete the table
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 8
Answer:

  • Elephas Maximus / Elephas Indicus
  • Pavo Cristatus
  • Canis Familiaris
  • Hibiscus Rosasinensis
  • Azadiracuta Indica
  • Oryza sativa

Question 17.
What are limitations in the system of classification of Carl Linnaeus?
Answer:
Some lower organisms share the characters of both animals and plants. So it is difficult to recognize them as plants or animals. Linnaeus considered only plants and animals for his classification. Microscopic organisms like bacteria, fungus, protozoa, etc were not included either in plant kingdom or in animal kingdom. Certain animals which were included in the classification of Linnaeus show characters of both the animal and plant kingdoms. Eg: Euglena protozoan shows locomotory movements like animals, but it contains chlorophyll like plants.

Question 18.
7. Hints about some organisms are given below. Name the kingdom to which these organisms belong.
a. Multicellular heterotrophic organisms with a nucleus and capacity for locomotion.
b. Multicellular heterotropic, non-motile organisms with a nucleus.
c. Unicellular organisms with a nucleus.
d. Multicellular, autotroph, non-motile organisms with a nucleus
Answer:
a. Animalia
b. Fungi
c. Protista
d. Plantae

Question 19.
Write the scientific name of following animals and plants. Coconut, paddy, wheat, crow, mango, grapes
Answer:
Coconut – Cocos nucifera
Paddy – Oryza sativa
Wheat – Triticum aestivum
Crow – Corvus splendens
Mango – Mangifera indica
Grapes – Vitis vinifera

Question 20.
What are two important characters of species?
Answer:
1. Species is a group of organisms that can freely interbreed to produce fertile offsprings.
2. A group of organisms that closely resemble each other in structure biochemical makeup and external characteristics but which are genetically different. In one species there may be subspecies.

Question 21.
The method of classification adopted by Whittaker is much better than the method adopted by Carl Linnaeus the father of the science of classification. What is your response to this statement?
Answer:
The classification of Linnaeus had only two kingdoms, plants, and animals. He did not consider bacteria, protozoa, fungus, etc. Certain characters of animals considered by Linnaeus for classification are found in both the kingdoms, eg. photosynthesis found in plants is seen in some animals like Euglena. Certain characters of animals can be seen in plants also, eg certain types of algae. But Whittaker adopted the method of having five kingdoms including protozoa and bacteria.

  • Monera,
  • Protista
  • fungi
  • Plantae
  • animalia

Question 22.
Bacteria does not have a well defined Nucleus. Viruses are also like Bacteria. Why is it not possible to include viruses under Monera.
Answer:
Viruses exhibit living nature only when they enter the host cells. On other occasions, they do not exhibit living nature. But organisms in Monera are not like that.

Question 23.
How do the levels of classification of plants made by Carl Linnaeus differ from the levels of classification of Animals?
Answer:
Not much differences are there. In the place of ‘Order’ in animal classification, plant classification has series. And in the place of ‘Phylum’ in animal classification, plant classification has ‘Division’.

Question 24.
Find the level of classification and complete the given table.
Kerala Syllabus 8th Standard Basic Science Solutions Chapter 12 Why Classification 9
Answer:
1. Kingdom
2.Phylum Chordata
3. Mammalia
4. Mammalia
5. Species

Question 25.
Cell is the smallest unit of life. But there are certain organisms that live without cell too. Analyze this statement.
Answer:
Life is not possible without a cell. Viruses do not have cells. As it is so, it does not have life when it outside a living cell. As it enters a living cell, it will show the features of life forms. It makes use of the components of the host cell and continues to live. Though it does not have a cell, it can continue its life only after entering a host cell and by making use of its components.

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Question 26.
Observe the given statement, and write correct answer if you find false statements.
a. Aristotle is the Father of Biology.
b. John Ray is the Father of Botany.
c. Carl Linnaeus used the term ‘species’ for the first time.
d. Charaka proposed binomial nomenclature.
Answer:
a. True
b. False, Theophrastus
c. False, John Ray
d. False, Carl Linnaeus

Question 27.
What is the relationship between taxonomic keys and dichotomous key?
Answer:
Taxonomic keys are scientific indicators used to identify and classify plants and animals. Dichotomous keys is one of the popular taxonomic keys.

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