---

1. 🌿Need for Classification, Importance of Classification & Evolution of Classification Systems

📚 Introduction

Biological classification is the method of organizing and grouping living organisms based on their similarities and differences. Earth is home to over 8.7 million known species, with millions more yet to be discovered. To make the study of this vast biodiversity manageable, a systematic classification system is essential.

In this document, we will explore:

1. The need for classification.
2. Importance of classification in biology and daily life.
3. The evolution of classification systems from early ideas to modern methods.

---

✍️ 1. Need for Classification

● Why Do We Need to Classify Organisms ?

Classification helps us to:

1. Organize Diversity: There are millions of organisms on Earth. Without classification, understanding their characteristics and relationships would be impossible.
2. Study Easily: Grouping organisms with similar features helps in easy learning and comparison.
3. Understand Evolutionary Relationships: Classification reflects how organisms have evolved and are related to each other.
4. Identify Organisms Correctly: When organisms are classified, their identification becomes standardized and universal.
5. Predict Characteristics: If we know characteristics of one organism in a group, we can predict traits in others of the same group.
6. Help in Conservation: Classification helps scientists identify endangered species and design conservation strategies.

---

🌐 2. Importance of Classification

✅ Key Benefits

Purpose	Description
Scientific Study	Makes study of biology structured and systematic.
Communication	Universal names prevent confusion across languages and regions.
Medical Research	Understanding pathogens’ classification helps in disease control.
Agriculture	Identifying pests, crops, and their relatives aids in better farming.
Biodiversity Conservation	Helps identify key species for protection.

🔎 NCERT-Based Example:

• Mangifera indica (mango): From its classification, we know it’s an angiosperm, dicot, fruit-bearing plant.
• Homo sapiens: Classified under Animalia, Mammalia, etc. It shows our place in the evolutionary tree.

---

🔬 3. Evolution of Classification Systems

Classification systems have changed over time. Early methods were simple and based on appearance. As knowledge advanced, more scientific and genetic bases were used.

🔺 Stages in the Evolution:

---

① Aristotle’s Artificial System

• Time: 4th Century BCE
• Basis: Habitat (land, water, air)
• Limitation: Very simple, grouped unrelated organisms together

Example: Grouping whales with fishes just because both live in water.

---

② Two-Kingdom Classification – Carl Linnaeus (1735)

• Kingdoms:
  • Plantae
  • Animalia
• Basis: Presence of cell wall, mode of nutrition

✅ Advantage: Introduced Binomial Nomenclature (e.g., Homo sapiens) ❌ Limitation: No separation for unicellular, fungi, or prokaryotes

---

③ Three-Kingdom Classification – Ernst Haeckel (1866)

• Added Protista for unicellular organisms.
• Still combined prokaryotes and eukaryotes in Protista.

Example: Amoeba, Euglena put in Protista

---

④ Four-Kingdom Classification – Copeland (1956)

• Added Monera for prokaryotes

✅ Advantage: First to clearly separate prokaryotes ❌ Limitation: Fungi still under Plantae

---

⑤ Five-Kingdom Classification – R.H. Whittaker (1969)

Kingdom	Features	Examples
Monera	Prokaryotic, unicellular	E. coli, Nostoc
Protista	Eukaryotic, unicellular	Amoeba, Paramecium
Fungi	Eukaryotic, multicellular, saprophytic	Yeast, Rhizopus
Plantae	Eukaryotic, multicellular, autotrophic	Mango, Neem
Animalia	Eukaryotic, multicellular, heterotrophic	Human, Lion

✅ Most accepted traditional system ❌ Limitation: No place for viruses, molecular data ignored

---

⑥ Three-Domain System – Carl Woese (1990)

• Based on rRNA gene sequencing
• Domains:
  1. Bacteria (e.g., E. coli)
  2. Archaea (e.g., Methanogens)
  3. Eukarya (all eukaryotic organisms)

✅ Recognized genetic differences between Bacteria and Archaea ✅ More natural system based on molecular evolution

---

💎 Key Differences in Classification Systems

System	Key Feature	Drawback
Aristotle	Based on habitat	Unnatural groupings
Linnaeus	Two kingdoms, binomial names	Ignored microbes and fungi
Haeckel	Added Protista	Mixed prokaryotes and eukaryotes
Copeland	Added Monera	Fungi still with plants
Whittaker	Five biological kingdoms	Viruses not included
Carl Woese	Three domains (genetic basis)	Complex for beginners

---

✨ Viruses and Their Exception

• Viruses are acellular, show both living and non-living traits.
• Not classified in any kingdom or domain.

NCERT mentions: TMV, HIV, Bacteriophages

---

🎓 Summary: Why It Matters in NEET

• Classification is frequently asked in NEET as MCQs or comprehension-based questions.
• Focus on:
  • Five-kingdom and three-domain comparison
  • Characteristics of Monera, Protista, Fungi
  • Binomial nomenclature
  • Examples and exceptions like viruses

---

🔐 Conclusion

The journey from Aristotle’s basic ideas to Woese’s rRNA-based classification shows how science evolves with evidence. Classification is not just about names but about understanding the unity and diversity of life. It helps us explore life forms logically and contributes immensely to medicine, agriculture, and environmental conservation.

Understanding the need and evolution of classification builds a strong foundation for advanced biology and helps aspirants tackle NEET questions with clarity.

---

2. Three-Domain System of Classification

Subtopics:

• Proposed by Carl Woese
• Domains: Archaea, Bacteria, and Eukarya
• NCERT Examples
• Key Features and Comparisons

---

📚 Introduction

As biology advanced into the molecular era, scientists discovered that classifying life forms only based on structure or nutrition was not sufficient. Genetic studies revealed deeper evolutionary relationships. This led to the development of the Three-Domain System of Classification by Carl Woese in 1990, which revolutionized biological taxonomy.

This system divides all life into three major domains based on differences in their ribosomal RNA (rRNA) sequences and fundamental cellular characteristics.

---

🧐 Why Was a New System Needed ?

The five-kingdom system proposed by R.H. Whittaker in 1969 was widely accepted but had limitations:

• Prokaryotes (bacteria and archaea) were placed in a single kingdom, Monera.
• It did not account for molecular differences between types of prokaryotes.
• Advances in genetics and molecular biology showed that archaea are very different from bacteria.

To address this, Carl Woese introduced the Three-Domain System, focusing on genetic data, especially the structure of rRNA genes, which are highly conserved and reliable for tracing evolutionary lineage.

---

🌐 What is the Three-Domain System?

✍️ Proposed By:

• Carl Woese and his colleagues in 1990
• Based on comparative sequencing of 16S rRNA genes (for prokaryotes) and 18S rRNA genes (for eukaryotes)

🔎 Basis of Classification:

• Differences in ribosomal RNA (rRNA) sequences
• Membrane lipid structure
• Sensitivity to antibiotics
• Presence or absence of nuclear envelope
• Types of RNA polymerase

🌱 Domains Introduced:

1. Archaea
2. Bacteria
3. Eukarya

This system superseded the traditional kingdom-level classification and placed domains above kingdoms.

---

🤠 1. Domain Archaea

✔ Key Features:

• Prokaryotic, but genetically and biochemically distinct from true bacteria
• Have unique cell membrane lipids (ether-linked lipids)
• Cell wall lacks peptidoglycan (unlike Bacteria)
• Found in extreme environments (thermophiles, halophiles, methanogens)
• Can survive without oxygen (anaerobic)

🔎 Examples:

• Methanogens – Produce methane gas; found in cow dung and marshes
• Thermophiles – Survive in hot springs (e.g., Thermococcus)
• Halophiles – Live in highly salty environments (e.g., Halobacterium)

🔹 NCERT Reference:

• Archaebacteria are mentioned in NCERT as distinct from other prokaryotes and as ancient forms of life

✅ Importance:

• Used in biotechnology (e.g., enzymes from thermophiles used in PCR)
• Provide insight into early evolution of life on Earth

---

🤬 2. Domain Bacteria

✔ Key Features:

• Also called Eubacteria (true bacteria)
• Prokaryotic with peptidoglycan in cell wall
• Cell membrane has ester-linked lipids
• Can be autotrophic (photosynthetic or chemosynthetic) or heterotrophic
• Reproduce by binary fission

🔎 Examples:

• Cyanobacteria (Blue-Green Algae) – Photosynthetic bacteria like Nostoc, Anabaena
• E. coli – Found in human gut; model organism for research
• Lactobacillus – Converts milk to curd

🔹 NCERT Reference:

• Detailed under “Kingdom Monera”
• Cyanobacteria like Nostoc, Oscillatoria are mentioned

✅ Importance:

• Decomposers, nitrogen-fixers, pathogens, and industrially important microbes
• Antibiotic production, dairy fermentation, bioremediation

---

🎓 3. Domain Eukarya

✔ Key Features:

• Organisms with membrane-bound nucleus and organelles
• Cell division by mitosis and meiosis
• Complex cell structures
• Includes both unicellular and multicellular organisms

🌿 Kingdoms Included:

1. Protista
2. Fungi
3. Plantae
4. Animalia

🔎 Examples:

• Protista – Amoeba, Paramecium, Euglena
• Fungi – Yeast, Rhizopus, Penicillium
• Plantae – Mango (Mangifera indica), Neem
• Animalia – Homo sapiens, Lion, Earthworm

🔹 NCERT Reference:

• All four kingdoms are discussed under different headings
• Examples of each group provided extensively

✅ Importance:

• Eukaryotes are the most complex and evolved organisms
• Human beings, all animals, and plants fall under this domain

---

🔹 Comparison of the Three Domains

Feature	Archaea	Bacteria	Eukarya
Cell Type	Prokaryotic	Prokaryotic	Eukaryotic
Cell Wall	No peptidoglycan	Peptidoglycan present	Absent or cellulose/chitin
Membrane Lipids	Ether-linked	Ester-linked	Ester-linked
Nuclear Membrane	Absent	Absent	Present
Ribosomes	70S, unique structure	70S	80S
RNA Polymerase	Several types	Single type	Several types
Habitat	Extreme environments	Everywhere	Land, water, air
Reproduction	Asexual (binary fission)	Asexual (binary fission)	Sexual/asexual

---

📖 Evolutionary Significance

• Archaea and Eukarya are more closely related genetically than Archaea and Bacteria.
• Indicates that life diverged early into three fundamental lines.
• Archaea might represent some of the earliest life forms on Earth.

---

🎓 NEET-Relevant Key Points

• Domain concept is above kingdoms in hierarchy
• rRNA sequencing is the basis of classification
• Archaea are prokaryotic but biochemically different
• Eubacteria include Cyanobacteria (e.g., Nostoc) – photosynthetic bacteria
• Eukarya include humans and all multicellular organisms

---

🔍 NCERT Integration

• NCERT refers to Archaebacteria as ancient bacteria and highlights their unique habitats
• Cyanobacteria and E. coli mentioned under Monera
• Fungi, Plantae, Animalia described under separate sections of Biological Classification

---

🔐 Conclusion

The Three-Domain System proposed by Carl Woese is a revolutionary step in taxonomy. It reflects the true evolutionary history of organisms by considering genetic makeup rather than just physical traits. It resolved the confusion between archaea and bacteria and provided a natural framework for understanding life at the molecular level.

For NEET aspirants, mastering this system is essential, not only to score well but to build a strong conceptual foundation for higher biological studies.

---

3. Five Kingdom Classification

Subtopics:

• Proposed by R.H. Whittaker (1969)
• Basis of Classification
• Overview of Five Kingdoms (focus: Monera, Protista, Fungi)
• NCERT Examples
• Key Points

---

📚 Introduction

Classification is the systematic arrangement of organisms into groups based on similarities and differences. Over time, several systems of classification were proposed, but one of the most widely accepted models is the Five Kingdom Classification proposed by Robert H. Whittaker in 1969. It marked a significant shift in taxonomy by introducing ecological roles and cellular organization as criteria.

This classification provided a structured way to group the diversity of life based on various fundamental characteristics.

---

🧐 Why Five Kingdoms ?

Earlier classification systems, like the two-kingdom system (Plantae and Animalia), failed to accommodate microorganisms and unicellular organisms like fungi and algae.

Whittaker’s Five Kingdom Classification was needed because:

• It recognized prokaryotic and eukaryotic distinction.
• It separated unicellular and multicellular organisms.
• It included the mode of nutrition and ecological role (producer, consumer, decomposer).
• It considered phylogenetic relationships and reproduction.

---

🔍 Basis of Whittaker’s Classification

Whittaker classified organisms into five kingdoms using the following criteria:

1. Cell Structure:

• Prokaryotic (without nucleus): Monera
• Eukaryotic (with true nucleus): Protista, Fungi, Plantae, Animalia

2. Body Organization:

• Unicellular: Monera, Protista
• Multicellular: Fungi, Plantae, Animalia

3. Mode of Nutrition:

• Autotrophic (photosynthesis): Plantae
• Heterotrophic (ingestion or absorption): Animalia, Fungi
• Mixotrophic: Some Protists

4. Reproduction:

• Asexual or sexual reproduction
• Binary fission, budding, spore formation

5. Phylogenetic Relationships:

• Evolutionary history and common ancestry

---

🌿 The Five Kingdoms Overview

Whittaker divided life into the following five kingdoms:

1. Monera
2. Protista
3. Fungi
4. Plantae (Not detailed here)
5. Animalia (Not detailed here)

Note: NCERT Class 11 Chapter covers only Monera, Protista, and Fungi, Plantae & Animalia Covered in Next Chapters.

---

📄 Kingdom Monera

✔ Key Features:

• Prokaryotic organisms (no true nucleus)
• Unicellular
• Cell wall present (in most), made of peptidoglycan
• Reproduce asexually (binary fission)
• May be autotrophic (chemo/photosynthetic) or heterotrophic

🔎 Examples (NCERT-based):

• Cyanobacteria (Blue-Green Algae): Nostoc, Anabaena, Oscillatoria (photosynthetic)
• Bacteria: Lactobacillus, Streptococcus, E. coli
• Archaebacteria: Methanogens, Halophiles, Thermoacidophiles

🔹 NCERT Highlights:

• Describes three types: Archaebacteria, Eubacteria, and Cyanobacteria
• Mentions their roles in nitrogen fixation, decomposition, and industry

✅ Importance:

• Nitrogen-fixing bacteria: Help in agriculture
• Cyanobacteria: Photosynthetic role in ecosystems
• Pathogenic bacteria: Cause diseases (e.g., tuberculosis)
• Used in fermentation (e.g., curd production)

---

🌊 Kingdom Protista

✔ Key Features:

• Eukaryotic and unicellular
• Some colonial or multicellular (without tissue differentiation)
• Mostly found in aquatic environments
• Mode of nutrition: Autotrophic, heterotrophic, or mixotrophic
• Movement via cilia, flagella, or pseudopodia

🔎 Examples (NCERT-based):

• Protozoa: Amoeba, Paramecium, Entamoeba
• Algae: Euglena (mixotrophic), Chlamydomonas
• Slime moulds: Physarum
• Diatoms and Dinoflagellates: Peridinium, Ceratium

🔹 NCERT Highlights:

• Groups Protista into photosynthetic protists, slime moulds, and protozoans
• Highlights structures, locomotion, and nutrition modes

✅ Importance:

• Primary producers in aquatic food chains
• Disease-causing protozoans: Plasmodium (malaria)
• Biological indicators in water pollution studies
• Euglena shows both plant and animal features – good for evolutionary studies

---

🌟 Kingdom Fungi

✔ Key Features:

• Eukaryotic and multicellular (except yeast, which is unicellular)
• Heterotrophic: absorb nutrients from decaying matter (saprophytic) or living hosts (parasitic) or in symbiotic associations (mutualistic)
• Cell wall made of chitin
• Body structure: Mycelium composed of hyphae
• Reproduce by spores, asexually or sexually

🔎 Examples (NCERT-based):

• Yeast: Unicellular fungus
• Moulds: Rhizopus (bread mould)
• Mushrooms: Agaricus
• Penicillium: Antibiotic-producing fungus
• Lichens: Symbiotic association of fungi and algae

🔹 NCERT Highlights:

• Divides fungi into four major classes: Phycomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes
• Discusses reproduction types and ecological roles

✅ Importance:

• Decomposers: Recycle nutrients in nature
• Industrial use: Alcohol, bread, cheese
• Medicinal: Source of antibiotics (e.g., penicillin)
• Pathogenic fungi: Cause skin infections and plant diseases
• Lichens: Indicators of air pollution

---

📈 Comparative Summary

Feature	Monera	Protista	Fungi
Cell Type	Prokaryotic	Eukaryotic	Eukaryotic
Nucleus	Absent	Present	Present
Cell Wall	Peptidoglycan (some)	Variable (some have)	Chitin
Body Organization	Unicellular	Unicellular or colonial	Multicellular (mostly)
Nutrition	Auto/Heterotrophic	Auto/Hetero/Mixo	Heterotrophic (absorption)
Reproduction	Asexual (binary fission)	Asexual/Sexual	Asexual/Sexual (spores)
Habitat	Everywhere	Aquatic, moist	Moist, decaying organic matter

---

🎓 NEET-Relevant Key Points

• Whittaker’s classification is based on cell type, body complexity, nutrition, reproduction
• Only Monera are prokaryotic; rest are eukaryotic
• Yeast is a unicellular fungus
• Euglena shows both plant (photosynthesis) and animal (movement) traits
• Rhizopus and Penicillium reproduce by spores
• Nostoc and Anabaena are cyanobacteria (Monera), capable of nitrogen fixation

---

🤖 Mnemonics and Tricks

• Five Kingdoms: “My Poor Father Plants Apples” (Monera, Protista, Fungi, Plantae, Animalia)
• Monera Examples: “Can Lazy Elephants Make Noise” (Cyanobacteria, Lactobacillus, E. coli, Methanogens, Nostoc)
• Protista Locomotion: “C-F-P” – Cilia (Paramecium), Flagella (Euglena), Pseudopodia (Amoeba)
• Fungi Reproduction: Spores – think of “Spores Fall From Fungus”

---

🔐 Conclusion

The Five Kingdom Classification system by Whittaker remains one of the most significant frameworks in biology. It categorizes life based on a combination of cell type, body structure, nutrition, and evolutionary history. Though newer systems like the Three-Domain model have emerged, the five-kingdom model is still crucial for foundational understanding, especially at the school level.

For NEET aspirants, understanding the characteristics and examples of Monera, Protista, and Fungi is essential, as these are frequently tested in objective questions.

---

4. Kingdom Monera

Subtopics:

• Characteristics of Bacteria and Archaebacteria
• Types of Bacteria: Cocci, Bacilli, Spirilla, Vibrio
• Structure of Bacteria
• Modes of Nutrition: Autotrophic and Heterotrophic
• Reproduction: Binary Fission, Conjugation
• Cyanobacteria (Blue-Green Algae)
• Archaebacteria: Extremophiles
• Mycoplasma

---

📚 Introduction

Kingdom Monera includes the simplest and most ancient life forms: the prokaryotes. These unicellular organisms lack a true nucleus and membrane-bound organelles. Though structurally simple, they are biochemically diverse and play crucial roles in ecosystems and human health.

Organisms in Monera are found in every habitat, including extreme environments, and show immense variation in nutrition, metabolism, and reproduction.

---

📝 General Characteristics of Monera

• Cell Type: Prokaryotic (no true nucleus or membrane-bound organelles)
• Cell Wall: Present in most (except Mycoplasma); made of peptidoglycan
• Organization: Unicellular (can form colonies)
• Nucleus: Absent, genetic material lies naked in the cytoplasm
• Reproduction: Asexual (mainly by binary fission)
• Nutrition: Autotrophic or heterotrophic
• Habitat: Found in soil, water, air, extreme conditions (hot springs, salty lakes)

---

🏠 Classification of Bacteria

Bacteria are classified based on shape into four types:

1. Cocci:

• Spherical bacteria
• Found singly (monococcus), in pairs (diplococcus), chains (streptococcus), clusters (staphylococcus)
• Example: Streptococcus, Staphylococcus

2. Bacilli:

• Rod-shaped bacteria
• Example: Lactobacillus, Bacillus anthracis

3. Spirilla:

• Spiral or helical-shaped
• Example: Spirillum

4. Vibrio:

• Comma-shaped
• Example: Vibrio cholerae (causes cholera)

---

🔍 Structure of a Bacterial Cell (Study Briefly Other Chapters)

• Capsule: Slimy outer covering (may be present)
• Cell Wall: Made of peptidoglycan
• Plasma Membrane: Semi-permeable
• Cytoplasm: Gel-like fluid containing enzymes and ribosomes
• Nucleoid: Region with circular DNA (no true nucleus)
• Plasmid: Small circular DNA fragments
• Ribosomes: 70S type
• Flagella: For locomotion in some bacteria
• Pili/Fimbriae: Help in attachment and conjugation

---

🌿 Modes of Nutrition

1. Autotrophic Bacteria:

• Photoautotrophs: Use sunlight and CO₂ for food (photosynthesis)
  • e.g., Cyanobacteria (contain chlorophyll a)
• Chemoautotrophs: Obtain energy by oxidizing inorganic substances (e.g., nitrifying bacteria)
  • e.g., Nitrosomonas, Nitrobacter

2. Heterotrophic Bacteria:

• Saprophytic: Feed on dead organic matter
  • e.g., Bacillus subtilis
• Parasitic: Live on/in host, may cause diseases
  • e.g., Mycobacterium tuberculosis
• Symbiotic: Live in mutual association
  • e.g., Rhizobium in legume roots

---

👩‍👩‍👩 Reproduction in Bacteria

1. Binary Fission:

• Most common method
• One cell divides into two identical cells
• Rapid division: under ideal conditions, some bacteria divide every 20 minutes

2. Conjugation:

• Sexual-like process
• Direct transfer of DNA through a pilus from donor to recipient
• Increases genetic variation

Note: Bacteria may also exchange DNA via transformation (uptake from environment) and transduction (via viruses)

---

💧 Cyanobacteria (Blue-Green Algae)

• Autotrophic photosynthetic bacteria
• Contain chlorophyll a, phycocyanin
• Fix atmospheric nitrogen (in specialized cells called heterocysts)
• Found in water bodies and moist environments

🔹 NCERT Examples:

• Nostoc
• Anabaena
• Oscillatoria

✅ Importance:

• Nitrogen fixation in agriculture
• Primary producers in aquatic ecosystems
• Form symbiotic relationships with fungi to form lichens

---

🔬 Archaebacteria (Ancient Bacteria)

Unique group of bacteria adapted to extreme environments. Their cell walls lack peptidoglycan.

✔ Characteristics:

• Cell membrane has branched lipids
• DNA sequences and enzymes differ from other bacteria
• Live in harsh environments

📄 Types of Archaebacteria:

1. Halophiles:

• Thrive in salty environments (e.g., salt lakes)
• Example: Halobacterium

2. Thermoacidophiles:

• Live in hot, acidic environments (e.g., hot springs)
• Example: Thermoplasma, Sulfolobus

3. Methanogens:

• Produce methane gas during anaerobic respiration
• Found in swamps, cow rumen, sewage treatment
• Example: Methanobacterium

✅ Importance:

• Methanogens used in biogas production
• Thermoacidophiles used in PCR enzymes (e.g., Taq polymerase)
• Provide clues about early life evolution

---

😷 Mycoplasma

• Smallest living organisms
• Lack cell wall – resistant to penicillin
• Can pass through bacterial filters
• Pleomorphic (variable shape)
• Parasitic or saprophytic
• Cause diseases in plants and animals

🔹 NCERT Highlights:

• Cause diseases like pleuropneumonia in cattle
• Survive without oxygen (anaerobic)

---

📌 Summary Table

Feature	Bacteria	Archaebacteria	Cyanobacteria	Mycoplasma
Nucleus	No	No	No	No
Cell Wall	Peptidoglycan	No peptidoglycan	Peptidoglycan	Absent
Habitat	Ubiquitous	Extreme environments	Aquatic, moist	Inside hosts
Nutrition	Auto/Heterotrophic	Chemoautotrophic	Photoautotrophic	Heterotrophic
Reproduction	Binary fission	Binary fission	Binary fission	Binary fission
Special Features	Conjugation, Plasmids	Extremophilic	Nitrogen fixation	No cell wall

---

📈 Key Points for NEET

• Monera are prokaryotes
• Cyanobacteria fix nitrogen and perform photosynthesis
• Archaebacteria live in extreme habitats – halophiles, thermophiles, methanogens
• Mycoplasma lack cell wall – not affected by penicillin
• Bacteria reproduce by binary fission (asexual) and conjugation (genetic exchange)
• Shapes of bacteria: Cocci (spherical), Bacilli (rod), Spirilla (spiral), Vibrio (comma)

---

🎓 Mnemonics for Easy Recall

• Bacteria Shapes: “CBS-V” → Cocci, Bacilli, Spirilla, Vibrio
• Archaebacteria Types: “Hi, Tell Me!” → Halophiles, Thermophiles, Methanogens
• Cyanobacteria Examples: “NOA” → Nostoc, Oscillatoria, Anabaena

---

🔐 Conclusion

Kingdom Monera, though comprising microscopic organisms, plays a macroscopic role in ecosystems and biotechnology. Bacteria are essential for nutrient recycling, fermentation, and nitrogen fixation, while archaebacteria expand our understanding of life’s adaptability. Cyanobacteria are pioneers in photosynthesis, and mycoplasma challenge definitions of minimal life.

Mastering the characteristics and diversity of Monera is crucial for NEET and lays the foundation for advanced microbiology.

---

5. Kingdom Protista

📚 Subtopics Covered:

• Characteristics of Protists
• Types of Protists:
  • Chrysophytes (e.g. Diatoms, Desmids)
  • Dinoflagellates
  • Euglenoids
  • Slime Moulds
  • Protozoans:
    • Amoeboid
    • Flagellated
    • Ciliated
    • Sporozoans

---

📄 Introduction

The Kingdom Protista is a diverse group of eukaryotic organisms that are primarily unicellular but exhibit varied modes of nutrition and reproduction. They act as a link between prokaryotes (Monera) and higher eukaryotes (Fungi, Plantae, Animalia).

All protists are eukaryotic (possess a true nucleus and membrane-bound organelles). They live in aquatic or moist environments and include autotrophs, heterotrophs, and mixotrophs.

---

🏠 General Characteristics of Protists

• Cell Type: Eukaryotic
• Organization: Mostly unicellular; some colonial or multicellular (without specialized tissues)
• Habitat: Freshwater, marine, moist soil
• Nutrition:
  • Autotrophic (photosynthetic)
  • Heterotrophic (ingestive or absorptive)
  • Mixotrophic (both modes)
• Reproduction:
  • Asexual (binary fission)
  • Sexual (syngamy, conjugation)

---

🛀 Types of Protists

1. Chrysophytes

Includes diatoms and desmids.

✔ Characteristics:

• Microscopic, photosynthetic
• Mostly aquatic (marine and freshwater)
• Rigid cell walls made of silica, forming frustules (glass-like walls)
• Diatoms form diatomaceous earth after death – gritty deposit useful in polishing and filtration
• Reproduce by binary fission and sexual methods

🔹 NCERT Examples:

• Navicula, Cymbella, Pinnularia

🔹 Importance:

• Primary producers in aquatic ecosystems
• Diatomaceous earth used in filtration, insulation, and as mild abrasives

---

2. Dinoflagellates

✔ Characteristics:

• Mostly marine, photosynthetic protists
• Cell wall made of cellulose plates (theca)
• Possess two flagella – one transverse, one longitudinal
• Exhibit bioluminescence in some species
• Reproduce mainly by asexual reproduction (binary fission)
• Rapid growth can cause red tides – toxic to marine animals

🔹 NCERT Examples:

• Gonyaulax, Noctiluca, Ceratium

🔹 Importance:

• Form the base of the marine food chain
• Some species are toxic and cause marine fish kills

---

3. Euglenoids

✔ Characteristics:

• Found in freshwater bodies
• Possess features of both plants and animals (mixotrophic)
• Have pellicle instead of cell wall – provides flexibility
• Possess two flagella (one long, one short)
• Photosynthetic in light; heterotrophic in the absence of light

🔹 NCERT Examples:

• Euglena, Phacus, Astasia

🔹 Importance:

• Act as producers in freshwater habitats
• Indicator organisms for pollution levels

---

4. Slime Moulds

✔ Characteristics:

• Saprophytic protists that feed on decaying matter
• Resemble fungi in their life cycle
• Under favorable conditions, form plasmodium – a multinucleate mass
• Under adverse conditions, produce fruiting bodies (sporangia) with spores
• Spores are resistant and dispersed by wind

🔹 NCERT Examples:

• Physarum, Fuligo

🔹 Importance:

• Decomposers – play a key role in nutrient recycling
• Provide clues to evolutionary links between fungi and protists

---

5. Protozoans

The animal-like protists, all are heterotrophic, mostly unicellular, and either free-living or parasitic.

✅ Classified into 4 Major Types:

a) Amoeboid Protozoans

• Move and capture food by pseudopodia (false feet)
• Found in freshwater, marine, and moist soil
• Some are free-living; others parasitic

Example: Amoeba (free-living), Entamoeba histolytica (causes amoebiasis)

b) Flagellated Protozoans

• Possess one or more flagella for movement
• May be free-living or parasitic

Example: Trypanosoma (causes African sleeping sickness)

c) Ciliated Protozoans

• Covered with cilia for movement and feeding
• Have pellicle that gives definite shape
• Possess two types of nuclei: macronucleus and micronucleus

Example: Paramecium

d) Sporozoans

• Non-motile, parasitic
• Reproduce by spore formation
• Complex life cycles involving multiple hosts

Example: Plasmodium (causes malaria)

---

📐 Summary Table

Group	Features	Examples
Chrysophytes	Silica wall, aquatic, photosynthetic	Navicula, Pinnularia
Dinoflagellates	Two flagella, bioluminescent, marine	Gonyaulax, Noctiluca
Euglenoids	Mixotrophic, pellicle, flagella	Euglena, Phacus
Slime Moulds	Saprophytic, form spores, resemble fungi	Physarum, Fuligo
Amoeboid	Pseudopodia for movement and feeding	Amoeba, Entamoeba
Flagellated	One or more flagella, parasitic	Trypanosoma
Ciliated	Cilia for movement, dual nuclei	Paramecium
Sporozoans	Spore-forming, parasitic	Plasmodium

---

🔹 Key Points for NEET

• Kingdom Protista includes eukaryotic unicellular organisms
• Diatoms have silica shells; form diatomaceous earth
• Dinoflagellates cause red tides and show bioluminescence
• Euglenoids behave like plants and animals (mixotrophic)
• Slime moulds are decomposers with fungus-like traits
• Protozoans are classified by locomotion: pseudopodia (Amoeba), flagella (Trypanosoma), cilia (Paramecium), non-motile spores (Plasmodium)

---

🎓 Mnemonics for Easy Learning

• Protists Types: “Can Dogs Eat Sweet Porridge?” → Chrysophytes, Dinoflagellates, Euglenoids, Slime Moulds, Protozoans
• Protozoa Types: “All Friendly Cats Sleep” → Amoeboid, Flagellated, Ciliated, Sporozoans
• Chrysophyte Examples: “Nice Pretty Creatures” → Navicula, Pinnularia, Cymbella

---

🌟 Conclusion

Kingdom Protista includes the most diverse forms of life – plant-like (algae), animal-like (protozoa), and fungus-like (slime moulds) – all in one kingdom. Protists are essential for nutrient cycling, oxygen production, food chains, and disease causation. For NEET aspirants, mastering their classification, structures, and examples ensures strong preparation.

---

6. Kingdom Fungi

📚 Subtopics Covered:

• General Characteristics of Fungi
• Modes of Nutrition
• Major Groups of Fungi:
  • Phycomycetes
  • Ascomycetes
  • Basidiomycetes
  • Deuteromycetes
• Reproduction in Fungi
• Economic Importance and Examples
• Lichens

---

📄 Introduction

Kingdom Fungi comprises a diverse group of eukaryotic, non-vascular, heterotrophic organisms. They may be unicellular or multicellular, and most fungi are saprophytic, meaning they obtain nutrients from dead organic matter. Some are parasitic or symbiotic. Fungi play essential roles in ecosystems, medicine, food, and industry.

---

🏠 General Characteristics of Fungi

• Cell Type: Eukaryotic
• Cell Wall: Composed of chitin or sometimes cellulose
• Nutrition: Heterotrophic – saprophytic, parasitic, or symbiotic
• Body Structure: Thallus-like, composed of hyphae forming a mycelium
• Habitat: Moist and warm places, decaying matter, soil, water, plants, animals
• Storage Material: Glycogen (like animals)
• Nucleus: Usually multinucleate cells

---

🍽️ Modes of Nutrition

1. Saprophytic:

• Most fungi absorb nutrients from dead organic matter.
• Examples: Rhizopus, Mucor

2. Parasitic:

• Live on living hosts, often causing diseases.
• Examples: Puccinia (causes rust disease in wheat)

3. Symbiotic:

• Mutualistic relationship with other organisms like algae or cyanobacteria.
• Example: Lichens (fungus + algae/cyanobacteria), Mycorrhiza (fungus + plant roots)

---

🛀 Major Groups of Fungi

1. Phycomycetes (Lower Fungi)

✔ Characteristics:

• Found in aquatic habitats, decaying wood, moist soils
• Aseptate, coenocytic hyphae (no cross walls)
• Reproduction:
  • Asexual: Zoospores (motile), aplanospores (non-motile)
  • Sexual: Fusion of gametes – isogamous, anisogamous, oogamous

🔹 NCERT Examples:

• Mucor, Rhizopus (bread mould), Albugo (parasitic)

2. Ascomycetes (Sac Fungi)

✔ Characteristics:

• Unicellular (yeasts) or multicellular
• Septate hyphae
• Reproduction:
  • Asexual: Conidia on conidiophores
  • Sexual: Ascospores in sac-like asci, arranged in ascocarps

🔹 NCERT Examples:

• Aspergillus, Claviceps, Neurospora, Saccharomyces (yeast)

3. Basidiomycetes (Club Fungi)

✔ Characteristics:

• Mostly multicellular, septate hyphae
• Commonly found in soil, wood, tree stumps
• Reproduction:
  • Asexual reproduction often absent
  • Sexual: Formation of basidiospores on club-shaped basidia, arranged in basidiocarps

🔹 NCERT Examples:

• Agaricus (mushroom), Puccinia (rust), Ustilago (smut)

4. Deuteromycetes (Fungi Imperfecti)

✔ Characteristics:

• Imperfect fungi: sexual reproduction not observed
• Only asexual reproduction by conidia
• Many are saprophytes or parasites
• Some later classified under Ascomycetes or Basidiomycetes after discovering sexual stages

🔹 NCERT Examples:

• Alternaria, Trichoderma, Colletotrichum

---

👅 Reproduction in Fungi

Fungi reproduce by vegetative, asexual, and sexual methods.

1. Vegetative Reproduction:

• By fragmentation, fission, or budding

2. Asexual Reproduction:

• Through spores: Zoospores, Conidia, Aplanospores, etc.

3. Sexual Reproduction:

• Involves 3 steps:
  • Plasmogamy (fusion of cytoplasm)
  • Karyogamy (fusion of nuclei)
  • Meiosis (formation of spores)
• Sexual spores: Zygospores, Ascospores, Basidiospores

---

💼 Economic Importance of Fungi

✅ Beneficial Roles:

• Food Industry:
  • Yeast (Saccharomyces cerevisiae) – baking and brewing
  • Edible fungi – Agaricus (mushroom)
• Antibiotics:
  • Penicillium notatum – produces penicillin
• Fermentation:
  • Aspergillus, Rhizopus – industrial production of citric acid, alcohol
• Genetics and Research:
  • Neurospora crassa – used in genetic studies
• Biofertilizers:
  • Mycorrhiza – symbiotic association that enhances water and nutrient uptake

❌ Harmful Roles:

• Plant Diseases:
  • Puccinia – rust in wheat
  • Ustilago – smut in maize
• Human Diseases:
  • Candida albicans – candidiasis
  • Aspergillus – respiratory infections

---

🤾 Lichens

✔ Definition:

Lichens are symbiotic associations between a fungus (mycobiont) and an alga or cyanobacterium (phycobiont).

✔ Characteristics:

• Algae perform photosynthesis; fungi provide water and protection
• Grow on tree bark, rocks, and soil
• Bioindicators of air pollution

🔹 NCERT Examples:

• Cladonia, Parmelia

---

📐 Summary Table

Group	Hyphae Type	Asexual Reproduction	Sexual Reproduction	Examples
Phycomycetes	Coenocytic	Zoospores, aplanospores	Isogamy, anisogamy, oogamy	Rhizopus, Mucor
Ascomycetes	Septate	Conidia	Ascospores in asci	Aspergillus, Yeast
Basidiomycetes	Septate	Usually absent	Basidiospores on basidia	Mushroom, Puccinia
Deuteromycetes	Septate	Conidia	Not observed	Alternaria, Colletotrichum

---

🎓 Mnemonics for NEET

• Fungi Types: “Poor Aunt Bakes Deliciously” → Phycomycetes, Ascomycetes, Basidiomycetes, Deuteromycetes
• Fungal Benefits: “FARM G”
  • Food
  • Antibiotics
  • Research
  • Mycorrhiza
  • Genetic studies

---

🌟 Key Points for NEET

• Fungi are eukaryotic, mostly multicellular (except yeast)
• Cell wall is made of chitin
• Reproduce by spores – asexual and sexual
• Penicillium produces penicillin, the first antibiotic
• Neurospora used in genetics
• Lichens = Fungus + Algae → symbiotic, pollution indicators

---

🌐 Conclusion

Kingdom Fungi is a vital biological group, contributing to ecosystems, medicine, and industries. Understanding the characteristics, classification, and roles of fungi is crucial for NEET and other competitive exams. These organisms not only serve as decomposers but also as tools for biotechnology and medicine. A clear grasp of fungal reproduction, examples, and ecological roles will enhance performance in NEET.

---

7. Viruses, Viroids, Prions, and Lichens

🪠 VIRUSES

💡 What are Viruses ?

Viruses are acellular (non-cellular) infectious agents that can only replicate inside living host cells. They are at the borderline between living and non-living things.

🔄 Dual Nature of Viruses

Nature	Description
Living	Can reproduce, mutate, evolve inside host cells
Non-living	Crystalline structure outside host; inert

---

🔹 Characteristics of Viruses

• Acellular (no cell structure)
• Obligate intracellular parasites (require a host)
• Possess either DNA or RNA, never both
• Surrounded by a protein coat (capsid)
• Lack enzymes for metabolism
• Do not grow or reproduce outside host

✔ NCERT Key Points

• Viruses did not find a place in the classification systems because they are not considered living by traditional definitions.
• They form crystals (e.g., tobacco mosaic virus) when outside the host.

---

🌀 Structure of Viruses

• Genetic Material: DNA (in bacteriophages) or RNA (in plant viruses)
• Capsid: Protein coat made of capsomeres
• Envelope: Some viruses have a lipid envelope (e.g., HIV)
• Tail and Fibers: Present in bacteriophages

🔹 NCERT Examples:

• Tobacco Mosaic Virus (TMV) – RNA virus in plants
• Human Immunodeficiency Virus (HIV) – Retrovirus in humans

---

🧬 Types of Viruses

1. Plant Viruses

• Infect plants
• Mostly contain single-stranded RNA (ssRNA)
• Example: TMV (Tobacco Mosaic Virus)

2. Animal Viruses

• Infect animals and humans
• Mostly contain DNA or RNA
• Example: Influenza virus, HIV, Herpes virus

3. Bacteriophages (Phages)

• Viruses that infect bacteria
• Genetic material: Double-stranded DNA (dsDNA)
• Structure: Head (DNA), tail sheath, tail fibers

✔ NCERT Example:

• T-even bacteriophage (infects E. coli)

---

🌊 Virus Reproduction Cycle

1. Lytic Cycle:

• Virus attaches → injects genetic material → host machinery replicates virus → cell bursts (lysis)
• Example: T4 bacteriophage

2. Lysogenic Cycle:

• Viral DNA integrates into host genome → replicates passively with host → can later become lytic

---

🪡 VIROIDS

🔄 Discovery:

• Discovered by T.O. Diener in 1971

🔹 Characteristics:

• Infectious RNA particles without a protein coat
• Smaller than viruses
• Circular, single-stranded RNA
• Cause diseases in plants

🔹 NCERT Example:

• Potato spindle tuber disease – caused by a viroid

🎓 NEET Tip:

Viroids are simpler than viruses and do not code for proteins.

---

💉 PRIONS

🔄 Discovery:

• Identified as proteinaceous infectious particles

🔹 Characteristics:

• Composed only of abnormally folded proteins
• No nucleic acid (DNA or RNA)
• Resistant to heat and radiation
• Cause neurodegenerative disorders

🔹 NCERT Example:

• Bovine Spongiform Encephalopathy (BSE), also called mad cow disease

🎓 Extra Info for NEET:

Prions convert normal brain proteins into abnormal forms, leading to brain damage.

---

🤾 LICHENS

🔄 Definition:

Lichens are symbiotic associations between a fungus (mycobiont) and an alga or cyanobacterium (phycobiont).

🔹 Characteristics:

• Mutualism: Fungus provides protection, algae provide food via photosynthesis
• Grow on rocks, tree bark, soil
• Sensitive to air pollution
• Slow growth, long lifespan

✔ NCERT Examples:

• Parmelia, Cladonia

🌟 Ecological Importance:

• Pioneer organisms in primary succession
• Bioindicators of air pollution
• Used in dye, perfume, and food industries

---

📐 Summary Table

Entity	Cell Structure	Genetic Material	Protein Coat	Reproduction	Host Required	Example
Virus	Acellular	DNA or RNA	Yes	Only in host	Yes	TMV, HIV, T-even phage
Viroid	Acellular	RNA	No	Only in host	Yes	Potato spindle tuber
Prion	Acellular	None	No	Converts proteins	Yes	BSE (Mad cow)
Lichen	Cellular (composite)	Algae: DNA, Fungus: DNA	Yes (fungal cells)	Reproduce by spores	No	Parmelia, Cladonia

---

📚 Key Differences

Feature	Virus	Viroid	Prion	Lichen
Composition	DNA/RNA + protein	RNA only	Protein only	Fungus + Alga
Structure	Capsid + genome	Naked RNA	Misfolded protein	Mycobiont + Phycobiont
Host Specificity	All life forms	Mostly plants	Animals	Free-living on surfaces

---

📅 NEET-Oriented Key Points

• Viruses are obligate parasites, not classified under any kingdom.
• TMV was the first virus to be crystallized (W.M. Stanley, 1935).
• Bacteriophages infect bacteria; used in molecular biology.
• Viroids lack protein coat but are infectious (plants).
• Prions are infectious proteins causing brain disorders.
• Lichens = Fungus + Alga, bioindicators of pollution.

---

🎓 Mnemonics for NEET 😘

Viruses – “VIRUS“: 😍

• V: Various forms (DNA/RNA)
• I: Infectious
• R: Replicate inside host
• U: Unicellular (not true cell)
• S: Symptom-causing

Lichens – “LIFE“: 😍

• L: Lichen
• I: Indicator of pollution
• F: Fungus (mycobiont)
• E: Eukaryotic partner (alga/cyanobacterium)

---

🌐 Real-life Applications

• Viruses: Vaccine development, gene therapy
• Viroids: Crop disease control
• Prions: Understanding neurodegenerative disorders
• Lichens: Environmental monitoring, dyes, cosmetics

---

📝 Practice Questions (For NEET)

1. Who discovered viroids and what disease do they cause?
2. What is the genetic material in bacteriophages?
3. Why are lichens good indicators of pollution?
4. Differentiate between viruses and prions.
5. Describe the structure of a typical virus.

---

🚀 Conclusion

Understanding the distinctions between viruses, viroids, prions, and lichens is essential for NEET. These entities challenge our classical definitions of life and play significant roles in health, disease, ecology, and industry. While viruses and viroids impact health and agriculture, lichens aid environmental conservation, and prions offer insights into brain biology.

---

🌿 Biological Classification – Important Conceptual Points

---

🔰 1. Need for Classification

• Vast diversity of organisms necessitates systematic arrangement.
• Classification helps in identification, study of relationships, and predicting characteristics.
• Early systems were based on utility (edible, medicinal, etc.), which lacked scientific basis.

---

📜 2. Evolution of Classification Systems

Classification Type	Features	Drawbacks
Two-Kingdom (Plantae & Animalia)	Based on presence/absence of cell wall	Could not classify organisms like fungi, bacteria, Euglena
Three-Kingdom	Added Protista	Still grouped prokaryotes with eukaryotes
Four-Kingdom	Added Monera	Improved separation but still vague for fungi
Five-Kingdom (R.H. Whittaker, 1969)	Based on cell type, structure, mode of nutrition, reproduction, phylogeny	Most widely accepted; NEET-relevant
Three-Domain System (Carl Woese, 1990)	Based on rRNA sequencing	Archaea separated from Bacteria

---

🌍 3. Three-Domain System (Carl Woese, 1990)

• Domains: Archaea, Bacteria, Eukarya
• Based on differences in ribosomal RNA (rRNA).
• Archaea: Extremophiles, distinct from true bacteria.
• Supported by molecular and genetic data.

---

🏰 4. Five-Kingdom Classification – Whittaker (1969)

Kingdom	Cell Type	Cell Wall	Body Form	Nutrition	Example
Monera	Prokaryotic	Yes (peptidoglycan)	Unicellular	Auto/heterotrophic	Bacteria
Protista	Eukaryotic	Present in some	Mostly unicellular	Auto/heterotrophic	Amoeba, Paramecium
Fungi	Eukaryotic	Chitin	Multicellular (except yeast)	Heterotrophic (saprophytic)	Mushroom
Plantae	Eukaryotic	Cellulose	Multicellular	Autotrophic (photosynthetic)	Mango tree
Animalia	Eukaryotic	Absent	Multicellular	Heterotrophic (ingestive)	Man

---

🦠 5. Kingdom Monera

Characteristics:

• Prokaryotic, unicellular
• Cell wall present (peptidoglycan)
• Reproduction: binary fission
• Nutrition: autotrophic (chemo & photo) or heterotrophic

Types of Bacteria:

• Cocci (spherical), Bacilli (rod-shaped), Spirilla (spiral), Vibrio (comma-shaped)

Cyanobacteria:

• Also called blue-green algae
• Photosynthetic (chlorophyll a)
• Found in aquatic habitats

Archaebacteria:

• Unique cell wall (no peptidoglycan)
• Extremophiles:
  • Methanogens (produce methane, e.g., in cow’s gut)
  • Halophiles (live in salty areas)
  • Thermoacidophiles (live in hot, acidic springs)

Mycoplasma:

• Smallest living cells
• No cell wall
• Pleomorphic, pathogenic

---

🧫 6. Kingdom Protista

Characteristics:

• Eukaryotic, mostly unicellular
• Aquatic
• Motile (via flagella, cilia, pseudopodia)
• Diverse modes of nutrition

Types:

1. Chrysophytes (e.g., diatoms): Silica cell wall, planktonic, photosynthetic
2. Dinoflagellates: Mostly marine, bioluminescent, red tides
3. Euglenoids: No cell wall, mixotrophic (e.g., Euglena)
4. Slime Moulds: Saprophytic, form spores
5. Protozoans:
   • Amoeboid (e.g., Amoeba)
   • Flagellated (e.g., Trypanosoma)
   • Ciliated (e.g., Paramecium)
   • Sporozoans (e.g., Plasmodium)

---

🍄 7. Kingdom Fungi

Characteristics:

• Eukaryotic, multicellular (except yeast, which is unicellular)
• Cell wall made of chitin
• Heterotrophic: saprophytic, parasitic, symbiotic
• Reproduction: vegetative (fragmentation), asexual (spores), sexual (fusion of gametes)

Major Groups:

1. Phycomycetes: Aquatic (e.g., Rhizopus)
2. Ascomycetes: Sac fungi, produce ascospores (e.g., Penicillium)
3. Basidiomycetes: Club fungi, basidiospores (e.g., Mushroom)
4. Deuteromycetes: Imperfect fungi (no sexual stage), e.g., Alternaria

Lichens:

• Symbiotic association of algae (phycobiont) and fungi (mycobiont)
• Indicators of air pollution

---

🧬 8. Viruses, Viroids, and Prions

Viruses:

• Acellular, obligate parasites
• DNA or RNA (never both)
• Crystallize outside host
• Examples: TMV, HIV, Bacteriophage

Viroids:

• Discovered by T.O. Diener
• Infectious RNA without protein coat
• Cause plant diseases (e.g., potato spindle tuber)

Prions:

• Infectious protein particles
• No nucleic acid
• Cause neurodegenerative diseases (e.g., Mad Cow Disease)

---

🍃 9. Lichens

• Mutualistic association between fungus and algae
• Fungus provides protection, algae does photosynthesis
• Grow on rocks, trees; very slow growth
• Sensitive to pollution – act as bioindicators

---

🧠 Extra Tips for NEET:

• Bacteriophage: Virus that infects bacteria (e.g., T4)
• Red Tides: Caused by dinoflagellates (e.g., Gonyaulax)
• Euglena: Link between plants and animals (mixotrophic)
• Yeast: Only unicellular fungus
• Mycoplasma: No cell wall, smallest living cell

---

🧾 Mnemonics:

• Five Kingdoms – “My Poor Father Plants Apple”
  (Monera, Protista, Fungi, Plantae, Animalia)
• Fungal Groups – “Please Ask Before Dating”
  (Phycomycetes, Ascomycetes, Basidiomycetes, Deuteromycetes)

---

📚 High-Yield Practice Questions

1. Name the extremophilic bacteria and their habitats.
2. Which protist causes malaria? Which group does it belong to?
3. Distinguish between lytic and lysogenic cycles of viruses.
4. Why is Euglena called a connecting link between plants and animals?
5. What makes fungi different from plants?

---

Thank You 💕By

🥰Learn Sufficient Notes🥰