Structure of a Cell - Nucleus - “Brain” of the Cell

Topics

Basic Biology
Cell - the Structure and Fundamental Unit of Life [For Revision Only]
- Cell: the Fundamental Unit of Life
- Organisms Show Variety in Cell Number, Shape and Size
- Plant Cell and Animal Cell
- Structure of a Cell
- Semi-permeable Membrane (Cell Membrane)
- Plasma Membrane
- Cell Wall - “Supporter and Protector”
- Nucleus - “Brain” of the Cell
- Cytoplasm - “Area of Movement”
- Endoplasmic Reticulum (ER)
- Mitochondria - “Power House of the Cell”
- Golgi Apparatus - "The delivery system of the cell"
- Ribosomes - "The sites of protein synthesis"
- Lysosome - “Suicidal Bag”
- Centrosome and Centrioles
- Plastids
- Non-living Substances Or Cell Inclusion
Cell Cycle, Cell Division and Structure of Chromosomes
- Chromosomes - The Carriers of Heredity
- Chromatin
- Deoxyribonucleic Acid (DNA) and Its Structure
- Histone Proteins
- Genes and Genetic
- Need for New Cells
- Cell Cycle - "Divide, Grow and Redivide"
- Cell Division: an Essential Life Process
- Mitosis and Its Phases
- Phases of Mitosis: Karyokinesis (Division of Nucleus)
- Phases of Mitosis: Cytokinesis (Division of Cytoplasm)
- Significance of Mitosis
- Meiosis as a Reduction Division
- Stages of Meiosis: Meiosis I
- Stages of Meiosis: Meiosis II
- Significance of Meiosis
Genetics – Some Basic Fundamentals
- Genes and Genetic
- Gregor Johann Mendel – Father of Genetics
- Heredity
- Variation
- Chromosomes - The Carriers of Heredity
- Types of Chromosomes
- Sex Determination
- Chromosomes - The Carriers of Genes
- Sex Linked Inheritance
- Mendelian Inheritance - Mendel’s Laws of Heredity
- Inheritance of One Gene (Monohybrid Cross)
- Inheritance of Two Genes (Dihybrid Cross)
- Mendel's Experiments Inheritance
- Mutation
Plant Physiology
Absorption by Roots : the Processes Involved
- Plant Anatomy and Plant Physiology
- Water and Mineral Absorption by Root
- Need of Water and Minerals for Plant
- Characteristics of Roots for Absorbing Water
- Semi-permeable Membrane (Cell Membrane)
- Means of Transport in Plants
- Concept of Imbibition
- Simple Diffusion
- Concept of Osmosis
- Osmotic Pressure
- Active Transport
- Turgidity and Flaccidity (Plasmolysis)
- Root Pressure
- Translocation of Water (Ascent of Sap)
Transpiration
- Transpiration
- Measurement of Transpiration
- Kinds of Transpiration
- Factors Affecting the Rate of Transpiration
- Adaptations in Plants to Reduce Excessive Transpiration
- Significance of Transpiration
- Direct Loss of Water by Plants - Guttation and Bleeding
Photosynthesis: Provider of Food for All
- Photosynthesis - Food Making Process in Plants
- Significance of Photosynthesis
- Chlorophyll – the Vital Plant Pigment
- Regulation of Stomatal Opening for Letting in Carbon Dioxide
- Process of Photosynthesis
- Role of Sunlight in Photosynthesis
- Light Dependent Reaction (Hill Reaction \ Light Reaction)
- Photophosphorylation
- Light Independent Reactions (Dark Reaction \ Biosynthetic Phase)
- Adaptations in Leaf to Perform Photosynthesis
- End Result of the Products of Photosynthesis
- Factors Affecting Photosynthesis
- Experiments on Photosynthesis
- The Carbon Cycle
- Respiration and Photosynthesis
Chemical Coordination in Plants
- Plant Hormones
- Types of Plant Hormones: Auxins
- Types of Plant Hormones: Gibberellins
- Types of Plant Hormones: Cytokinins
- Types of Plant Hormones: Ethylene
- Types of Plant Hormones: Abscisic Acid (ABA)
- Co-ordination in Plant: Tropism in Plants
Human Anatomy and Physiology
The Circulatory System
- Circulation
- Fluids in Our Body
- Blood
- Functions of Blood
- Composition of Blood: Plasma (The Liquid Portion of Blood)
- Composition of Blood: Red Blood Cells (Erythrocytes)
- Composition of Blood: White Blood Cells (Leukocytes)
- Composition of Blood: Blood Platelets (Thrombocytes)
- Function of Platelets - Clotting of Blood (Coagulation)
- Blood Transfusion and Blood Groups (ABO and Rh system)
- Blood Circulatory System in Human
- Human Heart
- Circulation of Blood in the Heart (Functioning of Heart)
- Circulation of Blood in the Heart: Cardiac Cycle
- Heart Beat - Heart Sounds "LUBB" and "DUP"
- Pacemaker
- Blood Vessels – Arteries, Veins, and Capillaries
- Types of Blood Circulation
- Blood Pressure (B.P.)
- Tissue Fluid (Or Intercellular Fluid)
- Lymph and Lymphatic System
- The Spleen
The Excretory System (Elimination of Body Wastes)
- Excretion: Substances to Be Eliminated
- Human Excretory System
- Kidney and Its Internal Structure
- Kidney Tubule (Nephrons)
- Function of the Kidney - “Production of Urine”
- Urine
- Osmoregulation
- Dialysis and Artificial Kidney
The Nervous System
- Human Nervous System
- Neuron as Structural and Functional Unit of Neural System
- Nerve Fibres
- Transmission of Nerve Impulse
- Synapse
- Major Division of the Nervous System
- The Human Brain
- Central Nervous System (CNS): Structure of Human Brain
- Peripheral Nervous System (PNS)
- The Spinal Cord
- Reflex and Reflex Action
- Types of Reflexes
- Nervous Pathways in Reflexes
- Reflex Arc
- Complex Reflex Action
- Sense Organ
- The Eyes
- Human Eye: Structure of the Eye
- Working of the Human Eye
- Eye Defect and Its Correction: Myopia Or Near-sightedness
- Eye Defect and its correction: Hypermetropia or far-sightedness
- Eye Defect and Its Correction: Presbyopia
- Eye Defect and Its Correction: Astigmatism
- Some Common Defects of the Eye
- Stereoscopic (Binocular) Vision
- Functions of the Ear
- Human Ear
The Endocrine System
- Need for the Regulation of Body Activities
- Hormones
- Human Endocrine System
- Adrenal Gland (Suprarenal Gland)
- Pancreas (Islets of Langerhans)
- Thyroid Gland
- Pituitary Gland or Hypophysis Gland
- Control of Hormonal Secretions
- Difference in Endocrine and Exocrine Glands
The Reproductive System
- Reproduction in Animal and Human
- Mode of Reproduction in Animal
- Asexual Reproduction in Animal
- Sexual Reproduction in Animals
- Human Reproductive System
- The Male Reproductive System
- The Female Reproductive System
- Role of Hormones in Reproduction
- Menstrual Cycle (Ovarian Cycle)
- Fertilization in Human
- Implantation in Human
- Pregnancy in Humans
- Placenta (Growth) in Human
- Embryonic Development in Human
- Parturition (Birth) in Human
Human Evolution
- Evolution
- Lamarck’s Theory of Evolution
- Darwin’s Theory of Natural Selection
- Vestigial Organs
- Origin and Evolution of Man
Population - The increasing numbers and rising problems
- Population Explosion - Rising Population a Global Threat
- World Population Through the Ages
- Rapid Rise in Population
- A Highly Simplified Model of Population Growth
- Population
- Factors Responsible for Population Explosion in India
- Problems of Over Population
- Rising Population - Pressure on Natural Resources
- Population Growth
- Consequences of Urbanisation
- Terms Related to the Population
- Population Control
- Family Planning
Pollution - A Rising Environmental Problem
- Waste and Its Categories
- Pollution and Its Types
- Air Pollution and Its Causes
- Prevention of Air Pollution
- Water Pollution and Its Causes
- Soil Pollution
- Radiation
- Noise Pollution
- Measures to Limit Noise Pollution
- Acid Rain
- Causes of Acid Rain
- Green House Effect
- Global Warming
- Ozone
- Ozone Layer Depletion
- Effects of Air Pollution
- Effects of Water Pollution
- Effects of Soil Pollution
- Control of Pollution
Physical Health and Hygiene
Health Organisations
- International Bodies: Who (World Health Organisation)
- Common Health Problems in India
Aids to Health
- Health
- First Aid and Emergency Action
- Antiseptics and Disinfectants
- Antibiotics

Nuclear Membrane
Nucleoli
Nucleoplasm
Chromatin fibres
Experiment: An experiment on amoeba to show that the nucleus is essential for a normal life.

Notes

Nucleus:

It is called the brain of the cell as it controls all the activities of cells.
It contains a double-layered nuclear membrane which has pores which allow the transfer of material in and out of the cell.
It contains chromosomes which contain information for the inheritance of features from parents to the next generation in the form of DNA (Deoxyribo Nucleic Acid) molecules.
Chromosome is available in the form of chromatin material in non- dividing cell. Whenever the cell is about to divide, the chromatin material gets organised into chromosomes and perform cell division.
The nucleus plays a central role in cellular reproduction in unicellular organisms.
Prokaryotes have an undefined nuclear region containing only nucleic acids and are called a nucleoid.