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Diversity in the Living World – CBSE NCERT Study Resources

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9th

9th - Science

Diversity in the Living World

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Diversity in the Living World

Chapter Overview

This chapter introduces students to the vast diversity found in the living world. It covers the classification of organisms, the basis of classification, and the hierarchy of biological organization. The chapter also explains the importance of biodiversity and the need for its conservation.

Biodiversity: The variety of life forms found on Earth, including different species of plants, animals, and microorganisms, their genetic differences, and the ecosystems they form.

Classification of Organisms

Organisms are classified based on their characteristics into groups and subgroups. The five-kingdom classification system proposed by R.H. Whittaker is widely used, which includes:

  • Monera
  • Protista
  • Fungi
  • Plantae
  • Animalia

Taxonomy: The branch of science that deals with the classification of organisms based on their similarities and differences.

Basis of Classification

The classification of organisms is based on several criteria, including:

  • Cell structure (prokaryotic or eukaryotic)
  • Body organization (unicellular or multicellular)
  • Mode of nutrition (autotrophic or heterotrophic)
  • Reproduction (sexual or asexual)

Hierarchy of Classification

The hierarchy of classification includes the following levels, from broadest to most specific:

  • Kingdom
  • Phylum (for animals) or Division (for plants)
  • Class
  • Order
  • Family
  • Genus
  • Species

Species: A group of organisms that can interbreed and produce fertile offspring under natural conditions.

Importance of Biodiversity

Biodiversity is essential for maintaining ecological balance and supporting life on Earth. It provides:

  • Food, medicine, and raw materials
  • Ecological services like pollination and soil fertility
  • Cultural and aesthetic value

Conservation of Biodiversity

Conservation of biodiversity is crucial to prevent the loss of species and ecosystems. Methods of conservation include:

  • In-situ conservation (protecting species in their natural habitats, e.g., national parks)
  • Ex-situ conservation (protecting species outside their natural habitats, e.g., zoos and seed banks)

All Question Types with Solutions – CBSE Exam Pattern

Explore a complete set of CBSE-style questions with detailed solutions, categorized by marks and question types. Ideal for exam preparation, revision and practice.

Very Short Answer (1 Mark) – with Solutions (CBSE Pattern)

These are 1-mark questions requiring direct, concise answers. Ideal for quick recall and concept clarity.

Question 1:
Define biodiversity.
Answer:

Variety of life forms in an ecosystem.

Question 2:
Name the five-kingdom classification system proposed by Whittaker.
Answer:
  • Monera
  • Protista
  • Fungi
  • Plantae
  • Animalia
Question 3:
What is the basic unit of classification?
Answer:

Species
Our textbook shows Panthera leo as an example.

Question 4:
Give one example of unicellular fungi.
Answer:

Yeast (NCERT example: Saccharomyces).

Question 5:
Which kingdom includes bacteria?
Answer:

Monera
Example: E. coli.

Question 6:
Name a vertebrate and an invertebrate.
Answer:
  • Vertebrate: Human
  • Invertebrate: Earthworm
Question 7:
What is the scientific name of humans?
Answer:

Homo sapiens (NCERT example).

Question 8:
Which group do mushrooms belong to?
Answer:

Fungi
Example: Agaricus.

Question 9:
Name an endangered species in India.
Answer:

Bengal Tiger (NCERT example).

Question 10:
What are thallophytes?
Answer:

Simple plants without roots, stems, or leaves (Example: Algae).

Question 11:
Give one example of gymnosperms.
Answer:

Pine tree (NCERT example: Pinus).

Question 12:
What is the role of lichens in nature?
Answer:

Bioindicators of air pollution (NCERT example).

Question 13:
Name a protozoan causing malaria.
Answer:

Plasmodium (NCERT example).

Question 14:
What are poriferans commonly called?
Answer:

Sponges (Example: Sycon).

Question 15:
What is the basis of classification of organisms?
Answer:

The basis of classification includes:

  • Cell structure (prokaryotic or eukaryotic)
  • Body organization (unicellular or multicellular)
  • Mode of nutrition (autotrophic or heterotrophic)
  • Reproduction (sexual or asexual)

Question 16:
Name the five-kingdom classification proposed by Whittaker.
Answer:

The five-kingdom classification includes:

  • Monera (bacteria)
  • Protista (unicellular eukaryotes)
  • Fungi (mushrooms, yeasts)
  • Plantae (plants)
  • Animalia (animals)

Question 17:
What is the role of lichens in an ecosystem?
Answer:

Lichens are bioindicators of air pollution and help in soil formation by breaking down rocks. They also provide food for some animals.

Question 18:
Differentiate between algae and fungi.
Answer:

  • Algae are autotrophic (make their own food via photosynthesis).
  • Fungi are heterotrophic (depend on dead or decaying matter).

Question 19:
Why are viruses considered non-living?
Answer:

Viruses lack cellular structure and cannot perform metabolic activities outside a host cell. They only show signs of life when inside a living organism.

Question 20:
What are endemic species? Give an example.
Answer:

Endemic species are organisms found only in a specific region and nowhere else. Example: Nilgiri tahr (found in Western Ghats).

Question 21:
Explain the term binomial nomenclature.
Answer:

Binomial nomenclature is the scientific naming system where each organism has a two-part name: Genus (capitalized) and species (lowercase). Example: Homo sapiens.

Question 22:
What is the importance of herbaria in taxonomy?
Answer:

Herbaria preserve dried plant specimens for study, helping scientists identify and classify plants accurately.

Question 23:
Name the levels of classification in hierarchical order.
Answer:

The levels of classification are:

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species

Question 24:
What are bryophytes? Give an example.
Answer:

Bryophytes are non-vascular plants that grow in moist areas. Example: Moss.

Question 25:
Why are prokaryotes placed in a separate kingdom?
Answer:

Prokaryotes lack a true nucleus and membrane-bound organelles, distinguishing them from eukaryotes.

Very Short Answer (2 Marks) – with Solutions (CBSE Pattern)

These 2-mark questions test key concepts in a brief format. Answers are expected to be accurate and slightly descriptive.

Question 1:
Define biodiversity and give one example.
Answer:

Biodiversity refers to the variety of life forms on Earth, including plants, animals, and microorganisms.
Example: The Amazon rainforest, which hosts thousands of species like jaguars, toucans, and orchids.

Question 2:
What is the significance of binomial nomenclature?
Answer:

Binomial nomenclature is a two-name system (Genus + species) for identifying organisms.
It avoids confusion caused by common names, e.g., Panthera tigris for tiger.

Question 3:
Name the five-kingdom classification system proposed by R.H. Whittaker.
Answer:
  • Monera (bacteria)
  • Protista (amoeba)
  • Fungi (mushrooms)
  • Plantae (trees)
  • Animalia (humans)
Question 4:
Why are viruses considered non-living?
Answer:

Viruses lack cellular structure and cannot reproduce outside a host.
They show life only inside living cells.

Question 5:
List two features of Monera kingdom.
Answer:
  • Unicellular, prokaryotic
  • No membrane-bound organelles
Question 6:
How do fungi differ from plants?
Answer:

Fungi lack chlorophyll (cannot photosynthesize) and have cell walls made of chitin.

Question 7:
What is the role of lichens in ecosystems?
Answer:

Lichens (fungi + algae) are bioindicators of air pollution and help in soil formation.

Question 8:
Name the scientist who introduced the term ‘biodiversity’.
Answer:

Walter G. Rosen coined the term in 1985.

Question 9:
Why are protists called ‘primitive eukaryotes’?
Answer:

They are the first eukaryotes with a nucleus but simpler than plants/animals (e.g., Paramecium).

Short Answer (3 Marks) – with Solutions (CBSE Pattern)

These 3-mark questions require brief explanations and help assess understanding and application of concepts.

Question 1:
Define biodiversity and explain its importance in maintaining ecological balance.
Answer:

Biodiversity refers to the variety of life forms, including plants, animals, and microorganisms, found in a particular habitat or on Earth as a whole.

It is crucial for maintaining ecological balance because:

  • It ensures stability in ecosystems by supporting food chains and webs.
  • It aids in nutrient cycling, soil formation, and climate regulation.
  • It provides resources like food, medicine, and raw materials for human survival.
Loss of biodiversity can disrupt ecosystems and lead to environmental degradation.

Question 2:
Differentiate between prokaryotic and eukaryotic cells with two examples of each.
Answer:

Prokaryotic cells are primitive cells lacking a defined nucleus and membrane-bound organelles, while eukaryotic cells have a well-defined nucleus and organelles.

Differences:

  • Nucleus: Prokaryotes lack a true nucleus (DNA floats freely), while eukaryotes have a membrane-bound nucleus.
  • Organelles: Prokaryotes lack membrane-bound organelles, whereas eukaryotes possess them (e.g., mitochondria, Golgi apparatus).
Examples:
  • Prokaryotes: Bacteria (e.g., E. coli), Archaea.
  • Eukaryotes: Amoeba, Human cells.

Question 3:
Explain the basis of classification of living organisms into five kingdoms as proposed by R.H. Whittaker.
Answer:

R.H. Whittaker classified organisms into five kingdoms based on:

  • Cell structure: Prokaryotic (Monera) vs. Eukaryotic (others).
  • Body organization: Unicellular (Protista) vs. Multicellular (Fungi, Plantae, Animalia).
  • Mode of nutrition: Autotrophic (Plantae), Heterotrophic (Animalia), or Saprophytic (Fungi).
  • Reproduction: Sexual or asexual methods.
The five kingdoms are: Monera, Protista, Fungi, Plantae, and Animalia.

Question 4:
What are lichens? Describe their ecological significance.
Answer:

Lichens are symbiotic associations between fungi (usually Ascomycetes) and algae or cyanobacteria.

Ecological significance:

  • They act as bioindicators of air pollution, as they are sensitive to sulfur dioxide.
  • They help in soil formation by breaking down rocks (biological weathering).
  • They provide food for animals like reindeer in tundra regions.
  • They contribute to nitrogen fixation when cyanobacteria are present.

Question 5:
Describe the key features of vertebrates and list the five classes with examples.
Answer:

Vertebrates are animals with a backbone or spinal column. Key features:

  • Presence of a well-developed brain protected by a skull.
  • Bilateral symmetry and segmented body plan.
  • Closed circulatory system with a ventral heart.
Five classes:
  • Pisces (e.g., Shark).
  • Amphibia (e.g., Frog).
  • Reptilia (e.g., Lizard).
  • Aves (e.g., Pigeon).
  • Mammalia (e.g., Human).

Question 6:
What are endemic species? Give two examples and explain why their conservation is important.
Answer:

Endemic species are organisms found exclusively in a specific geographic region and nowhere else.

Examples:

  • Lion-tailed macaque (Western Ghats, India).
  • Nilgiri tahr (Nilgiri Hills, India).
Conservation importance:
  • They contribute to genetic diversity and ecosystem stability.
  • They are often keystone species, playing critical roles in their habitats.
  • Their loss can disrupt local food chains and ecological processes.

Question 7:
Explain the basis of five-kingdom classification proposed by Whittaker.
Answer:

Whittaker classified organisms based on:
1. Cell structure (prokaryotic/eukaryotic).
2. Body organization (unicellular/multicellular).
3. Mode of nutrition (autotrophic/heterotrophic).
4. Reproduction (sexual/asexual).
5. Phylogenetic relationships (evolutionary history).

Kingdoms: Monera, Protista, Fungi, Plantae, Animalia.

Question 8:
Describe the role of lichens as bioindicators with an example.
Answer:

Lichens are symbiotic associations of algae and fungi. They are sensitive to air pollution, especially sulfur dioxide.

Example: Absence of lichens in cities indicates high air pollution. They thrive in clean air, making them natural bioindicators.

Question 9:
List three adaptations of xerophytes with explanations.
Answer:

Adaptations:
1. Thick cuticle: Reduces water loss.
2. Spines: Minimize surface area to prevent transpiration.
3. Deep roots: Absorb groundwater efficiently.

Example: Cactus survives in deserts using these features.

Question 10:
How do fungi differ from plants in terms of nutrition and cell wall composition?
Answer:

Nutrition:
1. Fungi are heterotrophic (absorb nutrients from dead matter).
2. Plants are autotrophic (photosynthesize).

Cell wall:
1. Fungi: Made of chitin.
2. Plants: Made of cellulose.

Long Answer (5 Marks) – with Solutions (CBSE Pattern)

These 5-mark questions are descriptive and require detailed, structured answers with proper explanation and examples.

Question 1:
Explain the five-kingdom classification system proposed by R.H. Whittaker with examples.
Answer:
Concept Overview

We studied that R.H. Whittaker classified organisms into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia based on cell structure, nutrition, and body organization.

Process Explanation
  • Monera: Unicellular, prokaryotic (e.g., bacteria).
  • Protista: Unicellular, eukaryotic (e.g., Amoeba).
  • Fungi: Multicellular, heterotrophic (e.g., Mushroom).
  • Plantae: Multicellular, autotrophic (e.g., Mango tree).
  • Animalia: Multicellular, heterotrophic (e.g., Humans).
Real-world Application

This system helps scientists study biodiversity systematically, like identifying harmful bacteria in labs.

Question 2:
Describe the characteristics of vertebrates and classify them with NCERT examples.
Answer:
Concept Overview

Vertebrates have a backbone and are grouped into five classes: Pisces, Amphibia, Reptilia, Aves, and Mammalia.

Process Explanation
  • Pisces: Gills, scales (e.g., Rohu).
  • Amphibia: Moist skin, live in water/land (e.g., Frog).
  • Reptilia: Dry scales, lay eggs (e.g., Lizard).
  • Aves: Feathers, beak (e.g., Pigeon).
  • Mammalia: Hair, mammary glands (e.g., Humans).
Real-world Application

Understanding vertebrates aids in wildlife conservation, like protecting endangered species such as tigers.

Question 3:
Differentiate between monocot and dicot plants using NCERT examples.
Answer:
Concept Overview

Monocots and dicots differ in seed leaves, venation, and floral parts.

Process Explanation
  • Monocots: Single cotyledon, parallel venation (e.g., Maize).
  • Dicots: Two cotyledons, reticulate venation (e.g., Gram).
Diagram
[Diagram: Comparison of monocot and dicot leaf venation]
Real-world Application

Farmers use this knowledge to identify crops, like distinguishing wheat (monocot) from pea (dicot).

Question 4:
Explain the importance of biodiversity with NCERT examples.
Answer:
Concept Overview

Biodiversity ensures ecological balance and provides resources for survival.

Process Explanation
  • Supports food chains (e.g., Bees pollinating crops).
  • Medicinal value (e.g., Tulsi for cold relief).
  • Maintains soil fertility (e.g., Earthworms).
Real-world Application

Protecting biodiversity prevents ecosystem collapse, like saving mangroves to reduce coastal erosion.

Question 5:
Describe the hierarchical classification system with examples from NCERT.
Answer:
Concept Overview

Organisms are grouped into taxa: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Process Explanation
  • Example: Humans belong to Animalia (Kingdom), Chordata (Phylum), Mammalia (Class), etc.
  • NCERT example: Mango is Plantae, Angiosperms, Dicotyledonae.
Real-world Application

Scientists use this to trace evolutionary relationships, like linking tigers to the cat family.

Question 6:
Describe the characteristics of vertebrates with examples from NCERT.
Answer:
Concept Overview

Vertebrates have a backbone and are grouped into five classes: Pisces, Amphibia, Reptilia, Aves, and Mammalia.

Process Explanation
  • Pisces: Gills, scales (e.g., Rohu).
  • Amphibia: Moist skin (e.g., Frog).
  • Reptilia: Dry scales (e.g., Lizard).
  • Aves: Feathers (e.g., Pigeon).
  • Mammalia: Mammary glands (e.g., Humans).
Real-world Application

Understanding these traits helps in wildlife conservation, like protecting endangered mammals.

Question 7:
Differentiate between gymnosperms and angiosperms with NCERT examples.
Answer:
Concept Overview

Gymnosperms and angiosperms are plant groups differing in seed structure.

Process Explanation
  • Gymnosperms: Naked seeds (e.g., Pine).
  • Angiosperms: Seeds in fruits (e.g., Mango).
  • Gymnosperms are mostly evergreen, while angiosperms can be deciduous.
Real-world Application

Angiosperms like wheat are staple food crops, while gymnosperms like pine provide timber.

Question 8:
Explain the economic importance of fungi with NCERT and real-life examples.
Answer:
Concept Overview

Fungi are economically significant as both beneficial and harmful organisms.

Process Explanation
  • Beneficial: Yeast (Saccharomyces) in baking.
  • Harmful: Penicillium spoils food.
  • Medicinal: Penicillium produces antibiotics.
Real-world Application

Fungi like mushrooms are cultivated for food, while others decompose waste.

Question 9:
How do prokaryotic and eukaryotic cells differ? Use NCERT examples.
Answer:
Concept Overview

Prokaryotic cells lack a nucleus, while eukaryotic cells have one.

Process Explanation
  • Prokaryotic: No organelles (e.g., bacteria).
  • Eukaryotic: Membrane-bound organelles (e.g., Amoeba).
  • Prokaryotes are smaller and simpler.
Real-world Application

Understanding this helps in medicine, like targeting bacterial (prokaryotic) infections.

Question 10:
Differentiate between angiosperms and gymnosperms with NCERT examples.
Answer:
Concept Overview

Angiosperms and gymnosperms are plant groups differing in seed structure.

Process Explanation
  • Angiosperms: Seeds enclosed in fruits (e.g., Mango).
  • Gymnosperms: Naked seeds (e.g., Pine).
Real-world Application

Angiosperms provide food, while gymnosperms are used for timber and resin.

Question 11:
Explain the importance of biodiversity with NCERT-based examples.
Answer:
Concept Overview

Biodiversity ensures ecological balance and provides resources.

Process Explanation
  • Supports food chains (e.g., Bees pollinating crops).
  • Medicinal value (e.g., Neem as antiseptic).
Real-world Application

Conserving biodiversity prevents ecosystem collapse, like protecting tigers in reserves.

Question 12:
Describe how fungi differ from plants with examples.
Answer:
Concept Overview

Fungi are heterotrophic, while plants are autotrophic.

Process Explanation
  • Fungi lack chlorophyll (e.g., Yeast).
  • Plants perform photosynthesis (e.g., Banyan tree).
Real-world Application

Fungi decompose waste, while plants produce oxygen for survival.

Question 13:
Explain the five-kingdom classification system proposed by R.H. Whittaker. Discuss the basis of classification and give one example for each kingdom.
Answer:

The five-kingdom classification system was proposed by R.H. Whittaker in 1969 to categorize living organisms based on specific characteristics. The five kingdoms are:

  • Monera: Includes unicellular, prokaryotic organisms (no nucleus). Example: Bacteria.
  • Protista: Consists of unicellular, eukaryotic organisms. Example: Amoeba.
  • Fungi: Multicellular, eukaryotic, heterotrophic organisms with cell walls made of chitin. Example: Mushroom.
  • Plantae: Multicellular, eukaryotic, autotrophic organisms with cell walls made of cellulose. Example: Mango tree.
  • Animalia: Multicellular, eukaryotic, heterotrophic organisms without cell walls. Example: Human.

The classification is based on:
1. Cell structure (prokaryotic/eukaryotic)
2. Body organization (unicellular/multicellular)
3. Mode of nutrition (autotrophic/heterotrophic)
4. Reproduction (sexual/asexual)

Question 14:
Differentiate between vertebrates and invertebrates with suitable examples. Also, explain why this classification is important in studying biodiversity.
Answer:

Vertebrates and invertebrates are two major groups of animals classified based on the presence or absence of a backbone.

  • Vertebrates: Have a well-developed backbone (vertebral column) and an internal skeleton. Examples: Humans, Fish, Birds.
  • Invertebrates: Lack a backbone and may have an exoskeleton or no skeleton. Examples: Earthworm, Butterfly, Octopus.

This classification is important because:
1. It helps in understanding the evolutionary relationships among species.
2. It aids in studying adaptations (e.g., vertebrates have complex nervous systems).
3. It simplifies biodiversity studies by grouping organisms with similar traits.

Question 15:
Describe the key features of angiosperms and gymnosperms. Compare their reproductive structures and provide two examples of each.
Answer:

Angiosperms and gymnosperms are two groups of seed-producing plants, but they differ in key features:

  • Angiosperms: Flowering plants with seeds enclosed in fruits. Examples: Mango, Rose.
    Reproductive structure: Flowers (produce seeds inside ovaries).
  • Gymnosperms: Non-flowering plants with naked seeds (not enclosed in fruits). Examples: Pine, Cycas.
    Reproductive structure: Cones (produce exposed seeds).

Comparison:
1. Seeds: Angiosperms have enclosed seeds; gymnosperms have exposed seeds.
2. Reproduction: Angiosperms use flowers; gymnosperms use cones.
3. Habitat: Angiosperms are more diverse; gymnosperms are mostly woody trees.

Question 16:
Explain the role of lichens as bioindicators of air pollution. How does their presence or absence reflect environmental quality?
Answer:

Lichens are symbiotic organisms (fungi + algae) that serve as excellent bioindicators of air pollution due to their sensitivity to pollutants like sulfur dioxide (SO₂).

Their role includes:
1. Absence in polluted areas: Lichens die in high SO₂ levels, indicating poor air quality.
2. Presence in clean areas: Thrive where air is pure, signaling a healthy environment.

Why they reflect environmental quality:
- They absorb nutrients directly from the air, making them vulnerable to toxins.
- Different species show tolerance levels (e.g., crustose lichens survive mild pollution; fruticose lichens need pristine air).

Example: If a city has no lichens, it suggests high pollution, while forests with diverse lichens indicate clean air.

Question 17:
Explain the five-kingdom classification system proposed by R.H. Whittaker. Discuss the basis of classification and give one example of each kingdom.
Answer:

The five-kingdom classification system was proposed by R.H. Whittaker to categorize living organisms based on specific characteristics. The five kingdoms are:

  • Monera: Includes unicellular, prokaryotic organisms (no nucleus). Example: Bacteria.
  • Protista: Consists of unicellular, eukaryotic organisms. Example: Amoeba.
  • Fungi: Multicellular, eukaryotic, heterotrophic organisms (absorb nutrients). Example: Mushroom.
  • Plantae: Multicellular, eukaryotic, autotrophic organisms (photosynthesis). Example: Mango tree.
  • Animalia: Multicellular, eukaryotic, heterotrophic organisms (ingest food). Example: Human.

The classification is based on:
1. Cell structure (prokaryotic/eukaryotic).
2. Body organization (unicellular/multicellular).
3. Mode of nutrition (autotrophic/heterotrophic).
4. Reproduction (sexual/asexual).

This system helps in understanding the diversity and evolutionary relationships among organisms.

Question 18:
Differentiate between vertebrates and invertebrates with suitable examples. Also, explain how the presence or absence of a notochord plays a role in their classification.
Answer:

Vertebrates and invertebrates are two major groups of animals classified based on the presence or absence of a backbone or vertebral column.

  • Vertebrates: Animals with a backbone and an internal skeleton. Example: Humans, fish, birds.
  • Invertebrates: Animals without a backbone. Example: Earthworms, insects, jellyfish.

The notochord is a flexible rod-like structure present during the embryonic development of vertebrates. It later develops into the vertebral column. Invertebrates lack a notochord entirely.

Key differences:
1. Skeletal System: Vertebrates have a well-developed internal skeleton, while invertebrates may have an exoskeleton or no skeleton.
2. Nervous System: Vertebrates have a complex nervous system with a brain and spinal cord, whereas invertebrates have simpler nerve nets or ganglia.
3. Size and Complexity: Vertebrates are generally larger and more complex in structure compared to invertebrates.

The presence of a notochord is crucial as it defines the phylum Chordata, which includes all vertebrates. Invertebrates belong to various other phyla where the notochord is absent.

Question 19:
Differentiate between vertebrates and invertebrates with suitable examples. Also, explain the significance of this classification in the study of biodiversity.
Answer:

Vertebrates and invertebrates are two major groups of animals classified based on the presence or absence of a backbone.

  • Vertebrates: Animals with a backbone and an internal skeleton. Examples: Human (mammal), Pigeon (bird), Frog (amphibian).
  • Invertebrates: Animals without a backbone. Examples: Earthworm (annelid), Butterfly (arthropod), Starfish (echinoderm).

Key differences:
1. Skeletal system: Vertebrates have a bony/cartilaginous skeleton, while invertebrates lack it.
2. Body size: Vertebrates are generally larger; invertebrates are smaller.
3. Nervous system: Vertebrates have a well-developed brain and spinal cord.

Significance of this classification:
1. Helps in understanding evolutionary relationships.
2. Aids in conservation efforts by identifying unique species.
3. Simplifies the study of animal characteristics and adaptations.

Question 20:
Explain the five-kingdom classification proposed by R.H. Whittaker. Discuss the basis of classification and give one example of each kingdom.
Answer:

The five-kingdom classification was proposed by R.H. Whittaker in 1969 to categorize living organisms based on specific characteristics. The five kingdoms are:

  • Monera: Includes unicellular, prokaryotic organisms (no nucleus). Example: Bacteria.
  • Protista: Consists of unicellular, eukaryotic organisms (have a nucleus). Example: Amoeba.
  • Fungi: Multicellular, eukaryotic organisms that are heterotrophic (absorb nutrients). Example: Mushroom.
  • Plantae: Multicellular, eukaryotic, autotrophic organisms (produce food via photosynthesis). Example: Mango tree.
  • Animalia: Multicellular, eukaryotic, heterotrophic organisms (ingest food). Example: Human.

The classification is based on:
1. Cell structure (prokaryotic vs. eukaryotic).
2. Body organization (unicellular vs. multicellular).
3. Mode of nutrition (autotrophic or heterotrophic).
4. Reproduction (sexual or asexual).
5. Phylogenetic relationship (evolutionary history).

This system helps in better understanding the diversity of life and simplifies the study of organisms by grouping them logically.

Question 21:
Explain the five-kingdom classification system proposed by R.H. Whittaker. Discuss the criteria used for this classification and provide examples of organisms belonging to each kingdom.
Answer:

The five-kingdom classification system was proposed by R.H. Whittaker in 1969 to categorize living organisms based on specific criteria. This system divides life into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia.

Criteria for Classification:
1. Cell Structure: Prokaryotic (no nucleus) or Eukaryotic (true nucleus).
2. Body Organization: Unicellular or Multicellular.
3. Mode of Nutrition: Autotrophic (self-feeding) or Heterotrophic (dependent on others).
4. Reproduction: Asexual or Sexual.
5. Phylogenetic Relationship: Evolutionary history.

Five Kingdoms with Examples:
1. Monera: Prokaryotic, unicellular; e.g., Bacteria, Cyanobacteria.
2. Protista: Eukaryotic, mostly unicellular; e.g., Amoeba, Paramecium.
3. Fungi: Eukaryotic, multicellular (except yeast), heterotrophic; e.g., Mushrooms, Yeast.
4. Plantae: Eukaryotic, multicellular, autotrophic; e.g., Mango tree, Rose plant.
5. Animalia: Eukaryotic, multicellular, heterotrophic; e.g., Humans, Dogs.

This classification helps in understanding the diversity of life and the relationships between different organisms. It is widely accepted due to its simplicity and scientific basis.

Question 22:
Explain the five-kingdom classification system proposed by R.H. Whittaker. Discuss the criteria used for this classification and provide examples of organisms belonging to each kingdom.
Answer:

The five-kingdom classification system was proposed by R.H. Whittaker to categorize living organisms based on specific criteria. This system divides organisms into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia.

Criteria used for classification:
1. Cell structure (Prokaryotic or Eukaryotic)
2. Body organization (Unicellular or Multicellular)
3. Mode of nutrition (Autotrophic or Heterotrophic)
4. Reproduction (Asexual or Sexual)
5. Phylogenetic relationship (Evolutionary history)

Examples of organisms in each kingdom:

  • Monera: Bacteria (e.g., E. coli), Cyanobacteria (e.g., Nostoc)
  • Protista: Amoeba, Paramecium, Euglena
  • Fungi: Yeast, Mushrooms, Molds
  • Plantae: Trees (e.g., Mango), Flowering plants (e.g., Rose)
  • Animalia: Humans, Dogs, Fish

This classification helps in understanding the diversity of life and the evolutionary relationships between organisms. It is widely accepted because it considers both structural and functional characteristics.

Case-based Questions (4 Marks) – with Solutions (CBSE Pattern)

These 4-mark case-based questions assess analytical skills through real-life scenarios. Answers must be based on the case study provided.

Question 1:
A student observed an amoeba under a microscope and noted its irregular shape and movement. Paramecium, another organism, showed coordinated movement using cilia. Compare their locomotion mechanisms and classify them.
Answer:
Case Summary

We studied amoeba and paramecium in our textbook. Amoeba moves via pseudopodia, while paramecium uses cilia.

Scientific Principle
  • Amoeba: Extends cytoplasm to form temporary pseudopodia.
  • Paramecium: Hair-like cilia beat rhythmically for movement.
Solution Approach

Both belong to Protista. Amoeba is shapeless, while paramecium is slipper-shaped. NCERT mentions them as unicellular eukaryotes.

Question 2:
A gardener found moss growing on damp soil and fern in shaded areas. Explain their reproductive differences and why they thrive in such habitats.
Answer:
Case Summary

Our textbook shows moss (Bryophyta) and fern (Pteridophyta) prefer moist environments.

Scientific Principle
  • Moss: Reproduces via spores, lacks vascular tissue.
  • Fern: Has vascular bundles, reproduces via spores but shows alternation of generations.
Solution Approach

Both need water for fertilization. NCERT highlights moss as non-vascular, while fern has true roots/stems, explaining their habitat preferences.

Question 3:
In a pond ecosystem, Spirogyra (green algae) and Volvox (colonial algae) were identified. Differentiate their structures and roles in the ecosystem.
Answer:
Case Summary

We studied Spirogyra (filamentous) and Volvox (colonial) in algae classification.

Scientific Principle
  • Spirogyra: Unbranched filaments with spiral chloroplasts.
  • Volvox: Hollow spherical colonies with interconnected cells.
Solution Approach

Both are autotrophs, producing oxygen. NCERT cites them as examples of Chlorophyta. Volvox shows division of labor, unlike Spirogyra.

Question 4:
A biologist found Hydra (Cnidaria) and Planaria (Platyhelminthes) in freshwater. Compare their body symmetry and digestive systems.
Answer:
Case Summary

Our textbook describes Hydra as radially symmetrical and Planaria as bilaterally symmetrical.

Scientific Principle
  • Hydra: Sac-like gut with single opening (incomplete).
  • Planaria: Branched digestive tract with mouth but no anus.
Solution Approach

NCERT classifies them as lower invertebrates. Hydra uses tentacles to capture prey, while Planaria scavenges. Both show regeneration.

Question 5:
A student observed an amoeba under a microscope and noted its irregular shape and movement. Paramecium, another unicellular organism, moves using cilia. Compare the locomotion and classification of these two organisms.
Answer:
Case Summary

We studied amoeba and paramecium as unicellular organisms in our textbook.

Scientific Principle
  • Amoeba moves using pseudopodia (false feet).
  • Paramecium uses cilia for swift movement.
Solution Approach

Both belong to Protista, but amoeba is a sarcodina, while paramecium is a ciliate. NCERT mentions their habitats—amoeba in ponds, paramecium in stagnant water.

Question 6:
A gardener found moss growing on a damp wall and fern in a shaded area. Explain their reproduction and why they thrive in such environments.
Answer:
Case Summary

We observed moss and fern as non-flowering plants in our NCERT chapter.

Scientific Principle
  • Moss reproduces via spores and needs moisture.
  • Fern has sporangia under leaves for spore dispersal.
Solution Approach

Both prefer damp areas as water aids spore germination. NCERT shows Funaria (moss) and Dryopteris (fern) as examples.

Question 7:
In a pond ecosystem, algae and hydra coexist. Describe their nutritional modes and roles in the food chain.
Answer:
Case Summary

Our textbook discusses algae as producers and hydra as consumers.

Scientific Principle
  • Algae perform photosynthesis (autotrophic).
  • Hydra is a carnivore (heterotrophic).
Solution Approach

NCERT mentions Spirogyra (algae) and Hydra vulgaris. Algae form the base, while hydra preys on smaller organisms.

Question 8:
A farmer grew wheat (monocot) and pea (dicot) plants. Compare their seed structure and leaf venation.
Answer:
Case Summary

We learned about monocots and dicots in NCERT.

Scientific Principle
  • Wheat has fibrous roots and parallel venation.
  • Pea shows taproot and reticulate venation.
Solution Approach

NCERT examples: Triticum (wheat) and Pisum (pea). Monocot seeds have one cotyledon, dicots have two.

Question 9:
A student observed an organism with chitinous cell walls and spore-bearing structures. Identify its kingdom and explain two features supporting this classification.
Answer:
Case Summary

The organism has chitinous cell walls and reproduces via spores.

Scientific Principle
  • We studied that Fungi have chitin in their cell walls.
  • Our textbook shows fungi like Mucor reproduce using spores.
Solution Approach

The organism belongs to Kingdom Fungi. Features: (1) Chitin provides structural support, (2) Spores aid in dispersal, as seen in bread mold.

Question 10:
In a pond, Paramecium and Amoeba were found. Compare their locomotion and nutrition modes using NCERT examples.
Answer:
Case Summary

Two protists, Paramecium and Amoeba, differ in movement and feeding.

Scientific Principle
  • Paramecium uses cilia (NCERT Fig. 5.6), while Amoeba moves via pseudopodia.
  • Both show holozoic nutrition but ingest food differently.
Solution Approach

Paramecium sweeps food via cilia, whereas Amoeba engulfs it (NCERT example). Real-world application: Both maintain pond ecosystems by decomposing matter.

Question 11:
A plant has taproots, reticulate venation, and two cotyledons. Classify it and relate one feature to its survival advantage.
Answer:
Case Summary

The plant shows dicot characteristics like taproots and reticulate veins.

Scientific Principle
  • We learned dicots (e.g., mustard in NCERT) have two cotyledons.
  • Taproots penetrate deeper for water, aiding drought survival.
Solution Approach

It’s a dicotyledon. Taproots provide stability and access to groundwater, as seen in sunflower (real-world example).

Question 12:
A marine animal has radial symmetry and spiny skin. Name its phylum and justify with two NCERT-based adaptations.
Answer:
Case Summary

The animal is radially symmetrical with spiny skin, living in marine habitats.

Scientific Principle
  • Our textbook mentions Echinodermata (e.g., starfish) have these traits.
  • Spines protect against predators (NCERT Fig. 7.16).
Solution Approach

Phylum: Echinodermata. Adaptations: (1) Radial symmetry aids omnidirectional movement, (2) Spines deter predators, like sea urchins.

Question 13:
In a biodiversity survey, students observed two organisms: Paramecium (unicellular) and Hydra (multicellular). Compare their characteristics based on cellular organization, mode of nutrition, and locomotion.
Answer:

Comparison between Paramecium and Hydra:

  • Cellular Organization: Paramecium is a unicellular organism, meaning it consists of a single cell performing all life functions. Hydra, on the other hand, is multicellular with specialized cells forming tissues.
  • Mode of Nutrition: Paramecium is heterotrophic, feeding on bacteria and small algae using its oral groove. Hydra is also heterotrophic but captures prey like tiny crustaceans using its tentacles with stinging cells.
  • Locomotion: Paramecium moves using cilia, tiny hair-like structures. Hydra exhibits sessile movement (attached to surfaces) but can perform somersaulting or gliding using its basal disc.

This comparison highlights how cellular complexity influences functionality in living organisms.

Question 14:
A student found a plant with needle-like leaves and cones. Identify its group and explain two adaptations that help it survive in cold climates.
Answer:

The plant belongs to the gymnosperms group, specifically conifers like pine or fir.

Adaptations for cold climates:

  • Needle-like leaves: These reduce surface area, minimizing water loss through transpiration and preventing snow accumulation.
  • Cones: Protect seeds from extreme cold and allow dispersal when conditions improve. The thick waxy coating on leaves and stems also prevents freezing damage.

These adaptations showcase how gymnosperms thrive in harsh environments, ensuring survival and reproduction.

Question 15:
Rahul observed two organisms in his garden: one had a chitinous cell wall, while the other had cellulose in its cell wall. Identify the kingdoms these organisms belong to and explain the key differences between them.
Answer:

The organism with a chitinous cell wall belongs to the Kingdom Fungi, while the one with a cellulose cell wall belongs to the Kingdom Plantae.


Key differences:

  • Nutrition: Fungi are heterotrophic (absorb nutrients from decaying matter), while plants are autotrophic (produce food via photosynthesis).
  • Cell composition: Fungi have chitin in their cell walls, whereas plants have cellulose.
  • Mobility: Fungi are non-motile, while some plants show movement (e.g., tropisms).

Additional insight: Fungi play a crucial role in decomposition, while plants are primary producers in ecosystems.

Question 16:
Priya found an organism with jointed legs, a segmented body, and an exoskeleton. Classify it into the correct phylum and explain two adaptive features that help it survive in its habitat.
Answer:

The organism belongs to the Phylum Arthropoda, as it exhibits jointed legs, a segmented body, and an exoskeleton made of chitin.


Adaptive features:

  • Exoskeleton: Provides protection from predators and prevents water loss, crucial for terrestrial survival.
  • Jointed appendages: Enable efficient movement (e.g., walking, flying, or swimming), aiding in foraging and escaping threats.

Example: Insects like ants or spiders use these features to thrive in diverse environments.

Question 17:
A group of students observed a pond ecosystem and noticed various organisms like fish, frogs, algae, and snails. They classified them into different groups based on their characteristics. Explain how these organisms can be classified under the five-kingdom classification system proposed by R.H. Whittaker. Provide reasons for your classification.
Answer:

The organisms observed in the pond can be classified under the five-kingdom classification system as follows:

  • Algae: Belongs to the kingdom Protista because they are unicellular or multicellular, photosynthetic, and lack specialized tissues.
  • Fish and Frogs: Belong to the kingdom Animalia because they are multicellular, heterotrophic, and have specialized tissues and organs.
  • Snails: Also belong to the kingdom Animalia as they are multicellular, heterotrophic, and have a hard shell, which is a characteristic feature of mollusks.

The five-kingdom classification system groups organisms based on cell structure, mode of nutrition, and body organization. This system helps in understanding the diversity of life forms and their evolutionary relationships.

Question 18:
In a biodiversity survey, a student observed two plants: one with well-differentiated roots, stems, and leaves, and another without such differentiation. Identify the groups to which these plants belong and explain the key differences between them.
Answer:

The two plants observed can be classified as follows:

  • Plant with well-differentiated roots, stems, and leaves: Belongs to the group Tracheophyta (vascular plants) because they have specialized tissues for conduction and support.
  • Plant without differentiation: Belongs to the group Bryophyta (non-vascular plants) because they lack true roots, stems, and leaves.

The key differences between these groups are:

  • Tracheophyta have vascular tissues (xylem and phloem) for water and food transport, while Bryophyta lack these tissues.
  • Tracheophyta are larger and can grow in diverse habitats, whereas Bryophyta are small and thrive in moist environments.
  • Tracheophyta reproduce via seeds or spores, while Bryophyta reproduce via spores only.

Understanding these differences helps in studying plant evolution and adaptation.

Question 19:
A group of students observed two organisms in their school garden: Earthworm and Butterfly. They noted that both belong to the animal kingdom but differ in body structure and habitat. Based on this, answer the following:

(a) Identify the phylum of each organism and list one distinguishing feature.
(b) Explain how their body symmetry differs and why it is important for their survival.
Answer:

(a) The Earthworm belongs to the phylum Annelida, characterized by a segmented body which aids in movement. The Butterfly belongs to the phylum Arthropoda, distinguished by jointed legs and a hard exoskeleton for protection.

(b) The Earthworm exhibits bilateral symmetry, meaning its body can be divided into two identical halves along a single plane. This helps in directional movement and efficient burrowing. The Butterfly also has bilateral symmetry, but its wings and body are adapted for flight, allowing precise navigation. Symmetry is crucial for balance, movement, and interaction with their environments.

Question 20:
In a pond ecosystem, a student observed Hydra and Spirogyra. While both are aquatic, they differ in their classification. Answer the following:

(a) Classify these organisms into their respective kingdoms and give one reason for each classification.
(b) Compare their modes of nutrition and explain how it relates to their structure.
Answer:

(a) Hydra belongs to the kingdom Animalia because it is a multicellular, heterotrophic organism capable of movement. Spirogyra belongs to the kingdom Plantae (or Protista in some classifications) due to its chlorophyll-containing cells, enabling photosynthesis.

(b) Hydra is a carnivore, using its tentacles to capture prey, which suits its predatory lifestyle. Spirogyra is autotrophic, producing food via photosynthesis, supported by its spiral chloroplasts for maximum light absorption. Their nutrition modes align with their structures: Hydra has a simple body with stinging cells, while Spirogyra has elongated cells for efficient photosynthesis.

Question 21:
A group of students observed a pond ecosystem and noticed various organisms like fish, frogs, algae, and aquatic plants. They classified these organisms into different kingdoms. Explain the basis of their classification and list the kingdoms to which these organisms belong, with reasons.
Answer:

The students classified the organisms based on the Five-Kingdom Classification system proposed by R.H. Whittaker. This system considers criteria like cell structure, mode of nutrition, and body organization.

  • Algae: Belongs to Kingdom Plantae because they are autotrophic (produce food via photosynthesis) and have cell walls made of cellulose.
  • Aquatic plants: Also part of Kingdom Plantae for the same reasons as algae, but they are multicellular and have well-defined structures like roots and leaves.
  • Fish and Frogs: Belong to Kingdom Animalia because they are heterotrophic (depend on other organisms for food), multicellular, and lack cell walls.

This classification helps in understanding the diversity and evolutionary relationships among living organisms.

Question 22:
During a field trip, students collected samples of moss, fern, and a flowering plant. Compare these plants based on their reproductive structures, habitat, and vascular system. How do these differences help in their classification?
Answer:

The three plants belong to different groups in the plant kingdom due to distinct features:

  • Moss:
    Reproductive Structure: Reproduces via spores in capsules.
    Habitat: Thrives in moist, shady areas.
    Vascular System: Non-vascular (lacks xylem and phloem).
    Classification: Bryophyta.
  • Fern:
    Reproductive Structure: Reproduces via spores under leaves.
    Habitat: Prefers damp, shaded environments.
    Vascular System: Vascular (has xylem and phloem).
    Classification: Pteridophyta.
  • Flowering Plant:
    Reproductive Structure: Reproduces via seeds enclosed in fruits.
    Habitat: Adaptable to diverse environments.
    Vascular System: Vascular (well-developed xylem and phloem).
    Classification: Angiosperms.

These differences highlight evolutionary advancements, such as the shift from spores to seeds and the development of vascular tissues, which improve survival in varied habitats.

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