Topics
Sexual Reproduction in Flowering Plants
- Flower
- Pre-fertilisation in Flowering Plant: Structures and Events
- Structure and Development of Anther
- Microsporogenesis
- Structure and Development of Male Gametophyte
- Pollen Viability and Storage
- Structure and Development of Ovule
- Megasporogenesis
- Development of Female Gametophyte or Embryo Sac
- Pollination
- Autogamy
- Geitonogamy
- Cross-pollination
- Agents of Pollination
- Anemophily
- Hydrophily
- Animal-Mediated Pollination (Zoophily)
- Outbreeding Devices
- Pollen Pistil Interaction
- Artificial Hybridization or Artificial Fertilization
- Double Fertilization and Triple Fusion
- Events in Sexual Reproduction > Post-Fertilization Structures and Events
- Endosperm
- Embryo
- The Seed
- Apomixis
- Polyembryony
Reproduction
Reproduction in Organisms
Human Reproduction
- Human Reproduction
- The Male Reproductive System
- The Female Reproductive System
- Gametogenesis
- Spermatogenesis
- Structure of Sperm
- Spermiogenesis
- Oogenesis
- Menstrual Cycle (Ovarian Cycle)
- Major Events of Menstrual Cycle
- Menstrual Hygiene
- Fertilisation in Human
- Implantation in Human
- Pregnancy and Embryonic Development
- Parturition (Birth) in Human
- Lactation in Human
Genetics and Evolution
Reproductive Health
- Concept of Reproductive Health
- Population Explosion and Control Measures
- Birth Control
- Natural Contraceptive Methods
- Artificial Contraceptive Methods
- Induced Abortion or Medical Termination of Pregnancy (MTP)
- Sexually Transmitted Diseases (STD) or Sexually Transmitted Infections (STI)
- Infertility
- Assisted Reproductive Technology (ART)
- Amniocentesis
- Genetic Counselling
Biology and Human Welfare
Principles of Inheritance and Variation
- Heredity and Variation
- Gregor Johann Mendel – Father of Genetics
- Mendel's Experiments on Inheritance
- Monohybrid Cross
- Punnett Square
- Back Cross and Test Cross
- Mendel's Laws > The Law of Dominance
- Mendel's Laws > The Law of Segregation (Law of Purity of Gametes)
- Exceptions to Mendel's Principles > Incomplete Dominance
- Exceptions to Mendel's Principles > Co-Dominance
- Dihybrid Cross
- Mendel's Laws > The Law of Independent Assortment
- Chromosomal Theory of Inheritance
- Linkage and Recombination
- Polygenic Inheritance
- Exceptions to Mendel's Principles > Pleiotropy
- Sex Determination
- Sex Determination in Humans
- Sex Determination in Honey Bees
- Mutations
- Pedigree Analysis
- Mendelian Disorders in Humans
- Chromosomal Disorders or Abnormalities
Environmental Issues
- Controlling Vehicular Air Pollution: a Case Study of Delhi
- Effects of Domestic Sewage and Industrial Effluents on Water
- Solid Wastes
- Radioactive Wastes
- Greenhouse Effect and Climate Change
- Ozone Depletion in the Stratosphere
- Degradation by Improper Resource Utilisation and Maintenance
- Radioactive Waste Management and E-waste
Biotechnology
Ecology
Molecular Basis of Inheritance
- Deoxyribonucleic Acid (DNA)
- Structure of Polynucleotide Chain
- Packaging of DNA Helix
- Search for Genetic Material
- Griffith’s Experiment
- Avery, McCarty and MacLeod’s Experiment
- The Hershey-Chase Experiment
- Properties of Genetic Material
- The RNA World
- DNA Replication
- Conservative Replication
- Dispersive Replication
- Semi-Conservative Replication
- Meselson and Stahl’s Experiment
- Enzymes used in DNA Replication
- Mechanism of DNA Replication
- Protein Synthesis
- Reverse Transcription (Teminism)
- Transcription
- Transcription Unit and the Gene
- Process of Transcription in Bacteria
- Process of Transcription in Eukaryotes
- Genetic Code
- Characteristics of the Genetic Code
- Mutations and Genetic Code
- tRNA – the Adapter Molecule
- Translation
- Regulation of Gene Expression
- The Lac Operon
- Human Genome Project
- DNA Fingerprinting
Evolution
Human Health and Diseases
- Concept and Determinants of Health
- Modes of Transmission of Diseases through Pathogens
- Diseases Caused by Bacteria > Typhoid
- Diseases Caused by Bacteria > Pneumonia
- Diseases Caused by Viruses > Common Cold
- Diseases Caused by Protozoa > Malaria
- Diseases Caused by Protozoa > Amoebiasis (Amoeboic dysentery)
- Diseases Caused by Helminths > Ascariasis
- Diseases Caused by Helminths > Filariasis (Elephantiasis)
- Diseases Caused by Fungi > Ringworm
- Prevention and Control of Infectious Diseases
- Immunity
- Types of Immunity > Innate Immunity
- Types of Immunity > Acquired Immunity
- Vaccination and Immunization
- Allergies
- Autoimmunity
- The Immune System
- Acquired Immuno Deficiency Syndrome (AIDS)
- Cancer
- Causes of Cancer
- Symptoms and Diagnosis of Cancer
- Prevention/Treatment of Cancer
- Drugs and Alcohol Abuse
- Addiction and Dependence
- Effects of Drug and Alcohol Abuse
- Prevention and Control of Drugs and Alcohol Abuse
Strategies for Enhancement in Food Production
Microbes in Human Welfare
Biotechnology - Principles and Processes
Biotechnology and Its Application
Organisms and Populations
- Organisms and Their Environment
- Population and Population Attributes
- Population Growth
- Life History Variation
- Population Interactions
- Negative Interactions > Predation
- Negative Interactions > Competition
- Negative Interactions > Parasitism
- Positive Interactions > Commensalism
- Positive Interactions > Mutualism (Symbiosis)
Ecosystem
Biodiversity and Its Conservation
Estimated time: 8 minutes
CBSE: Class 12
CISCE: Class 12
CISCE: Class 12
Symptoms of Cancer
Cancer may present with local or systemic symptoms.
A. Local Symptoms
Local symptoms arise in or near the affected organ or tissue.
- Persistent cough.
- Indigestion.
- Constipation or diarrhoea.
- Abdominal pain.
- Pain or difficulty during urination.
- Blood or mucus in urine or faeces.
- A lump that can be felt under the skin, in the breast, or in another body part.
B. General or Systemic Symptoms
These symptoms are usually noticed in later stages or when the disease begins to affect the body more widely.
- Loss of appetite.
- Unexplained weight loss.
- Tiredness or weakness.
- Persistent pain.
- Jaundice in some cases.
- Mood changes.
- Epileptic-type fits in certain conditions.
CBSE: Class 12
CISCE: Class 12
CISCE: Class 12
Detection and Diagnosis of Cancer
1. Biopsy:
A biopsy is the removal of a small piece of suspected tissue for examination. It is one of the most important diagnostic methods for confirming cancer.
2. Histopathological Study:
A histopathological study means microscopic examination of tissue to identify abnormal or cancerous cells. This method helps confirm the nature of the disease.
3. Blood and Bone Marrow Examination:
In leukaemias, blood tests and bone marrow examination may show abnormally increased cell counts. These tests are useful in diagnosing blood cancers.
4. Imaging Techniques:
Radiography and advanced imaging are used to detect cancers inside the body and to observe tissue changes.
| Technique | Basic Principle | Main Use in Diagnosis | Imp Point |
|---|---|---|---|
| X-ray / Radiography | Uses X-rays | Detects internal abnormalities | Useful for internal body examination. |
| CT Scan | Three-dimensional imaging using X-rays | Gives a more detailed internal view | Helpful in locating internal growths and tissue changes. |
| MRI | Uses a strong magnetic field and non-ionising radiations | Detects changes in internal organs and tissues | Does not use ionising radiation. |
5. Antibody-Based Detection:
Antibodies against cancer-specific antigens are used in detecting some forms of cancer. This method helps identify disease markers associated with tumour cells.
6. Molecular Diagnosis:
Molecular biology techniques can detect genes linked with inherited susceptibility to cancer. Individuals with such risk can be advised to avoid exposure to certain carcinogens.
CBSE: Class 12
CISCE: Class 12
CISCE: Class 12
Key Points: Symptoms and Diagnosis of Cancer
- Cancer is detected through biopsy (tissue sample stained and examined under a microscope), histopathological studies, and blood/bone marrow tests (for leukaemia).
- CT scan uses X-rays to produce 3D images of internal organs; MRI uses strong magnetic fields and non-ionising radiation to detect tissue changes.
- Antibodies against cancer-specific antigens are also used for detecting certain cancers.
- Molecular biology techniques identify genes associated with inherited cancer susceptibility, helping in early prevention.
- Individuals with inherited cancer susceptibility are advised to avoid specific carcinogens, e.g., tobacco smoke in case of lung cancer.
