NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Written by Team Trustudies
Updated at 2021-05-07
NCERT solutions for class 9 Science Chapter 7 Diversity In Living Organisms Exercise Questions
NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Answer :
(i) Classification helps in exploring the diversity of life forms.
(ii) It simplifies to study them for scientific research.
(iii) It helps in cross breeding and modification for commercial purpose.
(iv) It helps in interpreting the interrelation of humans with other organisms.
(v) It helps in studying the dependence and interactions between different organisms.
Q2 ) How would you choose between two characteristics to be used for developing a hierarchy in classification?
NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Answer :
The basis of the start of the hierarchy will be formed on the basis of the fine character.
1. Human beings are categorized under vertebrates as they possess the vertebral column.
2. Tetrapod is categorized on the basis of the existence of four limbs.
3. Mammals are categorized on the basis of presence of the mammary glands.
NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Answer :
The major characteristics which is considered for classifying all organisms into five major kingdoms are:
(a) On the basis of their structure and presence or absence of a well developed nucleus and membrane bound cell-organelles, i.e., prokaryotic and eukaryotic organisms.
(b) On the basis of presence of the number of cells which differentiates them into unicellular and multicellular organisms.
(c) On the basis of the presence of a cell-wall which differentiates them into plant cell and animal cell.
(d) On the basis of their mode of nutrition which differentiates them into autotrophs and heterotrophs.
(e) On the basis of their level of complexity of cell which categorizes them into cellular level of organization, tissue level of organization, organ level of organization and organ-system level of organization.
NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Answer :
|
Thallophyta |
Bryophyta |
Pteridophyta |
Gymnosperm |
Angiosperm |
|
It has a simple body design and is not differentiated into root, stem and leaves. |
Its body is differentiated into stem and leaf-like structures but the vascular system is absent. |
Its body is differentiated into root, stem and leaves and also have a vascular system, but the reproductive organs are inconspicuous with no seeds. |
They have reproductive organs where the seeds are naked as they don't have any protective covering. |
They have reproductive organs where the seeds are covered. |
Q5 ) How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?
NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Answer :
Plants are classified based on their morphological characteristics such as :-
On the basis of their cell structure they are classified as thallophytes, bryophytes and pteridophytes.
On the basis of their visibility of seeds they are classified as gymnosperms and angiosperms.
Animals are classified on the basis of their structural variations which are taken into account such as the levels of organization, body symmetry, germinal layers, nature of coelom, segmentation and presence of notochord.
NCERT Solutions for Class 9 Science Chapter 7 Diversity In Living Organisms
Answer :
Vertebrata has two main subclasses namely,
Pisces ( which have a streamlined body with tails and fins that helps them in swimming) and tetrapod ( which have four limbs for their movement).
The tetrapod animals are further classified into:
1. Amphibia : The animals belonging to this group are adapted to live in both land and water. They can breathe under the water through their skin and can breathe through the lungs when they are present on the land. They are cold-blooded and require an aquatic habitat to lay eggs. These organisms are mainly characterized by the presence of two pairs of limbs, smooth and moist skin for respiration.
2. Reptilia : The organisms of this group crawls for their movement. They are cold-blooded and are characterized by the presence of scales on their skin. Reptiles also lack an external ear and some reptiles such as snakes pick up vibrations through the ground.
3. Aves : The forelimbs of these organisms are modified into wings which help them in their flight. Most members of this group have a streamlined body which is specially designed to offer low air resistance during flight. Feathers play an important role in flight, thermal insulation and water-proofing. They are warm-blooded and are thus able to regulate their body temperature.
Aves have beak which help them in preening and feeding.
4. Mammalia : These organisms are distinguished by the presence of mammary glands. They have two pairs of limb for walking, grasping, swimming etc. Skin is covered by hair and they have an external ear called pinnae. They are warm-blooded and viviparous in nature.
