NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms

NCERT Solutions for Class 9 Science Chapter 7: NCERT Solutions for Class 9 Science Chapter 7, "Diversity in Living Organisms," provide a detailed understanding of the vast variety of life forms found on Earth. This chapter explains the classification of organisms into different kingdoms based on their characteristics and evolutionary relationships.

NCERT Solutions for Class 9 Science Chapter 7 Overview

NCERT Solutions for Class 9 Science Chapter 7 PDF

NCERT Solutions for Class 9 Science Chapter 7 PDF

NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms

NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Exercise – 7.1

Q1. Why do we classify organisms?

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Q2. Give three examples of the range of variations that you see in life forms around you.

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NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Exercise-7.1

Q3. Which of the following do you think is a more basic characteristic for classifying organisms?

(a) The place where they live.

(b) The kind of cells they are made of. Why?

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Q4. What is the primary characteristic on which the broad division of organisms is made?

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Q5. On what basis are plants and animals put into different categories?

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• This is a fundamental criterion for classification. Plants typically have cells surrounded by a rigid cell wall composed of cellulose, which provides structural support and protection. In contrast, animals generally lack a cell wall, allowing for greater flexibility and mobility.

• This criterion focuses on how organisms obtain and process nutrients. Plants are autotrophic, meaning they produce their own food through photosynthesis using sunlight, water, and carbon dioxide.
• Animals, on the other hand, are generally heterotrophic, meaning they rely on consuming other organisms or organic matter for nutrients.

NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Exercise-7.2

Q6. Which organisms are called primitive, and how are they different from the so-called advanced organisms?

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Q7. Will advanced organisms be the same as complex organisms? Why?

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NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Exercise-7.3

Q8. What is the criterion for the classification of organisms as belonging to the kingdom Monera or Protista?

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Monera (Prokaryotes):

• Organisms in the Monera kingdom are characterized by the absence of a true nucleus and other membrane-bound organelles. Their genetic material floats freely in the cytoplasm.
• Examples include bacteria and archaea.

Protista (Protists):

• Organisms in the Protista kingdom are primarily single-celled eukaryotes that possess a well-defined nucleus enclosed within a nuclear membrane.
• Protists exhibit a wide range of characteristics and can be autotrophic or heterotrophic. They include organisms like amoebas, algae, and protozoans.

Q9. In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic?

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Q10. In the hierarchy of classification, which grouping will have the smallest number of organisms with maximum common characteristics and which will have the largest number of organisms?

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Q11. Which division among plants has the simplest organisms?

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Q12. How are pteridophytes different from phanerogams?

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Pteridophytes:

• Embryo: They possess a naked embryo.
• Reproductive Organ: They exhibit unclear or less well-defined reproductive organs compared to Phanerogams.

Phanerogams:

• Embryo: They possess a covered embryo.
• Reproductive Organ: They exhibit well-defined reproductive organs, which may include flowers in angiosperms (flowering plants) and cones in gymnosperms.

Q13. How do gymnosperms and angiosperms differ from each other?

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NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Exercise-7.5

Q14. How do poriferan animals differ from coelenterate animals?

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Q15. How do annelid animals differ from arthropods?

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NCERT Solutions For Class 9 Science Chapter 7 Exercise

Q1. What are the advantages of classifying organisms?

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• Study of Common Features: Classification allows for the systematic study of organisms with shared characteristics, aiding in understanding their biology and evolution.
• Simplified Scientific Studies: It facilitates easier comparison and analysis of scientific experiments and observations across different species.
• Interpretation of Human Interactions: Classification helps in understanding the relationships and dependencies between humans and other organisms, including ecological roles and impact on ecosystems.
• Commercial Applications: It provides a framework for crossbreeding and genetic modification, leading to advancements in agriculture, medicine, and other commercial sectors.

Q2. How would you choose between two characteristics to be used for developing a hierarchy in classification?

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Start of Hierarchy (Gross Character): Organisms are initially classified based on prominent, easily observable features. For example, human beings are categorized as vertebrates due to the presence of a vertebral column.

Further Steps (Fine Character): Subsequent classification involves finer details and specific traits that distinguish groups within broader categories. For instance:

• Tetrapods: This group includes organisms with four limbs, such as amphibians, reptiles, birds, and mammals.
• Mammals: Further classification within tetrapods focuses on distinctive characteristics like the presence of mammary glands for lactation.

Q3. Explain the basis for grouping organisms into five kingdoms.

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1. Number of Cells: The first criterion considers whether the organism is unicellular (made of one cell) or multicellular (made of many cells).
2. Arrangement and Layers: This factor examines how cells are organized and the number of cellular layers present in the organism's body structure.
3. Presence of Cell Wall: Classification also considers whether organisms have a cell wall surrounding their cells, which can vary in composition and function.
4. Mode of Nutrition: Complex organisms are classified based on how they obtain and process nutrients. This includes whether they are autotrophic (produce their own food) or heterotrophic (obtain food from other sources).
5. Organization Level: The level of organization within an organism, such as cellular level, tissue level, or organ level, is also crucial in classification. This reflects how cells and tissues are specialized to perform specific functions within the organism.

Q4. What are the major divisions in the Plantae? What is the basis of these divisions?

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Q5. How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

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Plant Classification:

• Thallophytes vs. Bryophytes: These groups are classified based on the basic cell structure. Thallophytes have simpler, undifferentiated cells, while Bryophytes have more specialized cells that form primitive tissues.
• Gymnosperms vs. Angiosperms: Classification is based on the presence and visibility of seeds. Gymnosperms have naked seeds (not enclosed in a fruit), while Angiosperms have seeds enclosed within a fruit.

Animal Classification:

• Cytology: In animal classification, cytology (the study of cells) plays a crucial role. Minute structural variations at the cellular level are considered to distinguish different groups.
• Morphological Features: Characteristics such as cell layers, cytology, and overall morphology are significant in the classification of animals. These features help categorize organisms into higher hierarchical groups based on the presence or absence of specific traits.

Q6. Explain how animals in Vertebrata are classified into further subgroups.

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Vertebrata (Subclasses):

• Pisces: Fishes with streamlined bodies, tails, and fins for swimming.
• Tetrapoda: Tetrapod animals with four limbs for movement.

Tetrapoda (Classes):

1. Amphibia: Adaptive animals that can live both on land and in water, with specialized organs for underwater breathing.
2. Reptilia: Crawling animals with thick skin that can withstand extreme temperatures.
3. Aves: Birds with modified forelimbs for flight, lacking teeth and having a beak and feathers.
4. Mammalia: Animals with nurturing skills, possessing mammary glands for milk production, covered with hair, and most are viviparous (give birth to live young).

Benefits of NCERT Solutions for Class 9 Science Chapter 7

• Comprehensive Coverage: They provide thorough explanations and solutions to all questions and exercises in the NCERT textbook, ensuring students understand core concepts effectively.
• Concept Clarity: By following NCERT Solutions, students gain clarity on complex topics through simplified explanations and step-by-step problem-solving approaches.
• Self-Study Aid: Students can use NCERT Solutions independently for self-study, reinforcing learning outside of the classroom and enhancing their understanding of science concepts.
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