Major Eukaryotic Cell Organelles – Structure and Functions for NEET

-

🔬 What Are Eukaryotic Cells?

Cells with a true nucleus and membrane-bound organelles

Found in: Plants, animals, fungi, and protists

Bigger and more complex than prokaryotic cells



🧱 Major Eukaryotic Cell Organelles and Their Functions

1. Nucleus – The Control Center

Structure: Double membrane, nucleoplasm, nucleolus, nuclear envelope

Function: Stores DNA, regulates gene expression, controls cell activity


🧠 Mnemonic: “Nucleus = Newsroom (where instructions are made)”


2. Mitochondria – The Powerhouse

Structure: Double membrane, inner membrane folds = cristae, own DNA

Function: Site of ATP production via aerobic respiration


🧠 Mnemonic: “Mighty Mitochondria Makes Energy”


3. Endoplasmic Reticulum (ER) – Transport System

Rough ER: Has ribosomes; protein synthesis

Smooth ER: No ribosomes; lipid synthesis and detoxification


🧠 Mnemonic: “Rough = Ribosomes, Smooth = Steroids”


4. Golgi Apparatus – Packaging and Shipping

Structure: Stacked, flattened cisternae

Function: Modifies, sorts, and packages proteins and lipids into vesicles


🧠 Mnemonic: “Golgi = Courier Office”


5. Lysosomes – The Digestive Bags

Structure: Vesicles with hydrolytic enzymes

Function: Intracellular digestion, autolysis


🧠 Mnemonic: “Lysosome = Lysis + Some destruction”



6. Peroxisomes – Detox Centers

Structure: Small vesicles with oxidases and catalase

Function: Break down fatty acids and neutralize toxic substances like H₂O₂




7. Plastids – Found Only in Plant Cells

Types:

Chloroplasts – Photosynthesis

Chromoplasts – Pigments

Leucoplasts – Storage



🧠 Mnemonic:
“Chloroplast = Green + Glucose”


8. Ribosomes – Protein Factories

Structure: Non-membranous, made of rRNA and proteins

Function: Site of protein synthesis

Found on RER and floating freely in cytoplasm




9. Cytoskeleton – Structural Support

Microtubules + Microfilaments

Function: Cell shape, movement, intracellular transport



10. Vacuoles – Storage Units

Large central vacuole in plants; smaller in animals

Function: Stores nutrients, water, waste


🧠 Mnemonic: “Vacuole = Vault of the Cell”



11. Centrosome and Centrioles (in animal cells)

Help in spindle formation during cell division




📊 Quick Comparison Table

Organelle Membrane? Found In Function

Nucleus Double Plants + Animals Controls all cell activities
Mitochondria Double Both ATP production
ER Single Both Protein + lipid synthesis
Golgi Apparatus Single Both Packaging + transport
Lysosome Single Mainly Animals Digestion
Chloroplast Double Plants only Photosynthesis
Ribosome No Both Protein synthesis
Vacuole Single Both Storage

Comments

Post a Comment

Popular posts from this blog

🌱 Plant Growth and Development: Role of Hormones in NEET & CBSE Biology

-
Image
Introduction Plant growth and development are crucial chapters in both NEET and CBSE Class 11 Biology. Understanding how plants grow and how hormones regulate this process is important not just for exams, but also for grasping key concepts in plant physiology. --- 🌿 What is Plant Growth? Growth in plants refers to an irreversible increase in size, usually accompanied by an increase in dry mass. It involves cell division (mitosis), cell elongation, and cell differentiation. Plant growth is indeterminate, meaning it continues throughout their life due to the presence of meristems (actively dividing tissues). --- 🔍 Phases of Growth 1. Meristematic Phase – cells are actively dividing. 2. Elongation Phase – cells elongate and expand in size. 3. Maturation Phase – cells differentiate and mature into specific tissues. --- 📈 Growth Curve Follows a sigmoid curve (S-shaped). Has four phases: 1. Lag Phase (slow growth), 2. Log Phase (rapid growth), 3. Declining Phase (slowdown), 4....
Read more

NEET 2025 – Cell: The Unit of Life | NCERT-Based Notes + Diagrams

-
Image
Post Content: Introduction: "Cell: The Unit of Life" is a conceptual and factual chapter. NEET 2025 can include diagram-based MCQs and questions from cell organelles and types of cells. Focus on NCERT keywords and functions. 1. Discovery of Cell Discovered by Robert Hooke in 1665 (cork cell) Cell Theory by Schleiden & Schwann Rudolf Virchow: "Omnis cellula-e-cellula" – cells arise from pre-existing cells 2. Prokaryotic vs Eukaryotic Cells Feature Prokaryote (Bacteria) Eukaryote (Plants/Animals) Nucleus Absent Present Organelles No membrane-bound Membrane-bound Ribosome Type 70S 80S Cell Wall Peptidoglycan Cellulose (plants) 3. Cell Organelles Nucleus: Double membrane, contains nucleolus and chromatin Mitochondria: Powerhouse, double membrane, has its own DNA Plastids: Chloroplast: Green, photosynthesis, has DNA Endoplasmic Reticulum (ER): Rough ER: Protein synthesis Smooth ER: Lipid synthesis Golgi Apparatus: Modifies & packages proteins Lysosome...
Read more

Plant Growth Regulators: Types, Functions, and NEET Insights

-
Image
Introduction Plant Growth Regulators (PGRs) are organic compounds that influence physiological processes in plants. These are also called phytohormones and are essential for growth, development, dormancy, flowering, fruiting, and stress responses. For NEET aspirants, understanding PGRs is crucial as they frequently appear in exams. --- Types of Plant Growth Regulators 1. Auxins Discovered by F.W. Went. Promote cell elongation, apical dominance, root initiation, and prevent premature fruit drop. Example: Indole-3-acetic acid (IAA), NAA. 2. Gibberellins Discovered from the fungus Gibberella fujikuroi. Promote stem elongation, seed germination, and break dormancy. Example: GA₃ (Gibberellic acid). 3. Cytokinins Promote cell division, delay senescence, and stimulate lateral shoot growth. Example: Kinetin, Zeatin. 4. Abscisic Acid (ABA) Known as a stress hormone. Induces seed dormancy, stomatal closure, and inhibits growth. 5. Ethylene A gaseous hormone. Promotes fruit ripening, ...
Read more