Bihar Board Class 9th Science Book Solutions विज्ञान Chapter-7 Diversity in Living Organisms NCERT पर आधारित Text Book Questions and Answers Notes, pdf, Summary, व्याख्या, वर्णन में बहुत सरल भाषा का प्रयोग किया गया है.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms

Question 1.
Why do we classify organisms?
Answer:
The classification of organisms help us in the following ways –

It make the study of different types of organisms easy.
We can know all life forms together and as a whole.
It reveals the inter-relationship among the organisms.
It helps in the development of other life sciences.
Question 2.
Give three examples of the range of variations that you see in life forms around you.
Answer:
We can see range of variations in-

The life span of organisms e.g., mosquito lives for a few days while cow and dog lives longer.
The body colour of the organisms.
The shape and size of the organism’s body.
page 82

Question 1.
Which do you think is a more basic characteristic for classifying organisms?
(а) the place where they live.
(b) the kind of cells they are made of Why?
Answer:
(b) The kind of cells they are made of.
Reason : The organisms living in the same habitat may or may not have similarities. So, the place where they live cannot be a basis of classification.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms

Question 2.
What is the primary characteristic on which the first division of organisms is made?
Answer:
Whether the organism is made up of eukaryotic or prokaryotic cells, is the primary characteristic for first division.

Question 3.
On what bases are plants and animals put into different categories?
Answer:
Plants and animals are put into different categories on the basis of their mode of nutrition.

Page 83

Question 1.
Which organisms are called primitive and how are they different from the so-called advanced organisms?
Answer:
The organisms which have ancient body designs that have not changed very much, are called primitive organisms.
The, advanced organisms are those which have acquired their particular body designs relatively recently. As per the body designs, the primitive organisms have simple structures while, the advanced organisms have some more complex structures.

Question 2.
Will advanced organisms be the same as complex organisms? Why? —
Answer:
The advanced organisms once had been like these primitive organisms in the remote past. They have obtained a particular body design in course of time. It is possible that in course of their development, the advanced organisms will acquire ihore complex structures- so that they could live in the changing environment.

Page 85

Question 1.
What is the criterion for classification of. organisms as belonging to kingdom Monera or Protista?,
Answer:
Monera : These organisms are unicellular and their cell organelles are not covered with membranes.
Protista : The organisms which are unicellular and their cell organelles are covered with membranes, are – placed in Protista Kingdom.

Question 2.
In which kingdom will you place an organism which is single-celled, eukaryotic and photo-synthetic?
Answer:
In Protista.

Question 3.
In the hierarchy of classification, which grouping will have the smallest number of organisms with a maximum of characteristics in common and which will have the largest number of organisms ?
Answer:
Species have smallest number of organisms having maximum similarities in common. The kingdom has maximum number of organisms.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms
Page 88

Question 1.
Which division among plants has the /simplest organisms?
Answer:
Thallophyta.

Question 2.
How are pteridophytes different fr&m phanerogams?
Answer:
Pteridophytes :

1. Have open embryo.
2. Have hidden reproduc- tive organs hence, also called ‘cryptogams’ meaning hidden reproductive organs.

Phanerogams :

1. Seeds are enclosed within the fruit.
2. Reproductive organ is distinct and divided into reproductive tissue. They develop fruits and seeds after reproduction.

Question 3.
How do gymnosperms and angiosperms differ from each other?
Answer:
Gymnosperms :

1. They have conical shaped sporophylls containing male and female reproductive organs.
2. Seeds are not enclosed within fruits.

Angiosperms :

1. They have flowers bearing male and female reproductive organs.
2. Seeds are enclosed within fruits.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms
Page 94

Question 1.
How do poriferan animals differ from coelenterate animals?
Answer:
Porifera :

1. Their body has many pores called Otiose.
2. They have canal system for circulation of water:
3. They have exo skeleton.
4. They don’t have tentacles.

Coelenterate :

1. Their body has a single pore.
2. They don’t have canal system.
3. They don’t have skeleton.
4. They have tentacles.

Question 2.
How do annelida animals differ from arthropods?
Answer:
Annelida :

1. They have true body cavity.
2. The coelomic cavity does not have blood.
3. There are lateral appendages for locomotion.

Arthropoda :

1. They have coelomic cavity.
2. The coelomic cavity is filled with blood.
3. They have jointed legs that help in locomotion.

Question 3.
What are the differences between amphibians and reptiles?
Answer:
Amphibia :

1. They live both on land and in water.
2. Body is covered with scales.
3. Their eggs don’t have any hard covering around them.
4. They lay eggs in water.
5. Water is necessary for reproduction.

Reptilia :

1. They live either on land or in water.
2. They also have scales on their body.
3. The eggs have hard covering.
4. Water is not necessary for laying eggs.,
5. Water is not necessary for reproduction.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms
Question 4.
What are the differences between animals belonging to the Aves group and those in the Mammalia group?
Answer:
Aves :

1. They have beaks.
2. They have their body covered with feathers.
   3.Anterior lirabs transform into wings.
3. They lay eggs.
4. They don’t have mammary glands to feed their young ones milk.

Mammalia :

1. They don’t have beaks.
2. They have their body covered with hairs.
3. Does not happen so.
4. Most of them give birth to young ones.
5. They have mammary glands for producing milk.

Bihar Board Class 9 Science Chapter 7 Diversity in Living Organisms Textbook Questions and Answers
Question 1.
What are the advantages of classifying organisms ?
Answer:
Classifying of organisms helps us in the following ways-

This makes the study of different kinds of organisms easy.
We can know all types of organisms at once.
It tells us about inter-relationship’among the organisms.
It helps in the development of other life science.
Question 2.
How would you choose between two characteristics to be used for developing a hierarchy in classification?
Answer:
We choose that characteristics which depends on the first characteristics and determines the next variety.

Question 3.
Explain the basis for grouping organisms into five kingdoms.
Answer:

Whether the organism is eukaryotic or prokaryotic.
Whether the organism is unicellular or multicellular.
Whether the cell has a tell wall or not.
Whether they make their food on their own or not.
Question 4.
What are the major divisions in the Plantae? What is the basis for these divisions?
Answer:
Five major divisions are-

Thallophyta
Bryophyta
Pteridophyta
Gymnosperms
Angiosperms
Basis of division :

Whether the plants have distinct organelles or not.
Whether the plants have distinct and ’- differentiated tissues, which can carry food and water, or not.
The plant has seeds or not.
The seeds are enclosed within fruits or not.
Question 5.
How are the criteria for deciding divisions in plants different from the criteria for deciding the sub-groups among the animals?
Answer:
Criteria for plants –

Presence of distinct organs.
Distinct vascular tissues.
Seed producing capacity.
Are seeds enclosed within fruits.
The animals can’t be divided into groups on these criteria. The animals are divided on the basis of their body structure.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms

Question 6.
Explain how animals in Vertebrata are classified into further subgroups?
Answer:
Vertebrates can be further classified into subgroups. This is based on simple to complex body structures and their functions. For examples – Fishes have two chambered heart, Amphibians have three chambered heart and Birds and Mammals have four chambered hearts. These are chambered to keep oxygenated and deoxygenated blood separate.

Bihar Board Class 9 Science Chapter 7 Diversity in Living Organisms Textbook Activities
Activity 7.1

Question 1.
We have heard of ‘desi’. cows and Jersey cows.

Does a desi cow look like a Jersey cow ?
Do all desi cows look alike ?
Will we be able to identify a Jersey cow in a crowd of desi cows that don’t look like each other, t
What is the basis of our identification ?
Answer:

No, they two are different.
No, they differ from each other.
Yes, the Jersey cow can be identified in a crowd of desi cows.
We can identify the Jersey cow on the basis of skin , colour, height, length of horn,’etc.
Activity 7.2

Soak seeds of green gram, wheat, maize, peas and tamarind. Once they become tender, try to split the seed. Do all the seeds break into two nearly equal halves ?
The seeds that do are the-dicot seeds and the seeds that don’t are the monocot seeds.
Now’ take a look at the roots, leaves and flowers of these plants.
Are the roots tap-roots or fibrous ?
Do the leaves have parallel or reticulate venation ?
(i) Are the roots tap-roots or fibrous?
(ii) Do the leaves have parallel or reticulate venation ?
(iii) How many petals are found in the flowers of these plants?
(iv) Can you write down further characteristics of monocots and dicots on the basis of these observa-tions?
Answer:
(i) The roots of wheat and maize are fibrous while peas, tamarind and gram have tap roots.
(ii) Wheat and maize have parallel venation. While, peas, tamarind and gram have reticulate venation.
(iii) The flowers of wheat and maize plants have petals in the multiples of three while those of pea, tamarind and gram plants have petals in the multiples of four or five.
(iv) Characteristics of monocots
(a) They have single cotyledon in seed.
(b) They have parallel venation in leaves.
(c) They have petals in the multiples of three.
(d) They have fibrous roots.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms

Characteristics of dicots :
(a) They have two cotyledons in seed.
(b) They have reticulate venation in leaves.
(c) They have petals in the multiples of four or five.
(d) They have tap roots.

Activity 7.3

Find out the names of the following animals and plants in as many languages as you can : .

1. Tiger
2. Peacock
3. Ant
4. Neem
5. Lotus
6. Potato
   Answer:
   Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms – 1
   Bihar Board Class 9 Science Chapter 7 Diversity in Living Organisms Additional Important Questions and Answers
   Question 1.
   What is important in forming desired category ?
   Answer:
   Characteristic properties are important in forming desired category.

Question 2.
Name the largest animal and tree.
Answer:
Blue whale (30 m long) is the largest animal and Redwood.is the largest tree.

Question 3.
What is meant by classifi-cation of living organisms ? ‘ .
Answer:
To categorise living organisms on the basis of their similarities and dissimilarities is called classification.

Bihar Board Class 9 Science Solutions Chapter 7 Diversity in Living Organisms
Question 4.
What is the basis of classification (in animals)?
Answer:
Habitat is the main basis of classification. On the basis of their habitats, animals can be classified into following categories –
(a) Terrestrial
(b) Aquatic
(c) Aerial.

Question 5.
What were the bases of classification of organisms into five groups?
Answer:
Following were the bases –
(i) Cell structure
(ii) The mode of obtaining foods and their source
(iii) Composition of the body.

Question 6.
Who suggested the monera group?
Answer:
Carl Woese had suggested monera group and placed archibacteria and embacteria in this group.

Question 7.
What is the basic unit of classification?
Answer:
Species.

Question 8.
Define species.
Answer:
The group of organisms which show similarity and can reproduce among themselves is called species.

Question 9.
Name the major terms used in classification of living organisms.
Answer:

Kingdom – Animal and plant kingdoms.
Phylum (for animals)/Division (for plants)
Class
Order
Family
Genus
Species.