Topics
Sexual Reproduction in Flowering Plants
- Flower - a Fascinating Organ of Angiosperms
- Parts of Flower
- Accessory Organs
- Essential Parts of Flower: Androecium
- Essential Parts of Flower: Gynoecium
- Sexual Reproduction in Flowering Plants
- Pre-fertilisation in Flowering Plant: Structures and Events
- Development of Anther
- Transverse Section of Mature Anther (Microsporangium)
- Microsporogenesis
- Microspores and Pollen Grains
- Development of Male Gametophyte
- Advantages and Disadvantages of Pollen Grains
- Structure of Ovule (Megasporangium)
- Types of Ovules
- Megasporogenesis
- Development of Female Gametophyte or Embryo Sac
- Pollination
- Outbreeding Devices
- Artificial Hybridization
- Kinds of Pollination
- Self Pollination (Autogamy)
- Cross Pollination
- Agents of Pollination
- Abiotic Agents
- Biotic Agents
- Fertilization Process
- Fertilization Process
- Post Fertilisation in Plant: Structures and Events
- Development of Endosperm
- Post Fertilization in Plant: Development of Embryo (Embryogeny)
- Development of Seed
- Development of Fruit
- Apomixis
- Polyembryony
Reproduction in Organisms
- Life Span of Organisms
- Maximum Life Span of Organisms
- Reproduction in Organisms
- Types of Reproduction
- Asexual Reproduction
- Sexual Reproduction in Animals
- Asexual Reproduction in Plant
- Asexual Reproduction in Animal
- Budding
- Vegetative Reproduction
- Natural Vegetative Reproduction
- Artificial Vegetative Reproduction
- Artificial Vegetative Reproduction
- Artificial Vegetative Reproduction
- Fission
- Budding
- Sporulation (Sporogenesis)
- Fragmentation
- Different Phases in Sexual Reproduction
- Sexual Reproduction in Animals
- Pre-fertilisation Events in Organisms
- Fertilisation in Organisms
- Post-fertilisation Events in Organisms
Reproduction
Genetics and Evolution
Human Reproduction
Reproductive Health
Biology and Human Welfare
Environmental Issues
- Environmental Issues
- Prevention of Air Pollution
- Controlling Vehicular Air Pollution: a Case Study of Delhi
- Introduction of Water Pollution and Its Control
- Effects of Domestic Sewage and Industrial Effluents on Water
- A Case Study of Integrated Waste Water Treatment
- Solid Wastes
- Agrochemicals and Their Effects
- Radioactive Wastes
- Greenhouse Effect and Climate Change
- Ozone Depletion in the Stratosphere
- Degradation by Improper Resource Utilisation and Maintenance
- Deforestation and Its Causes
- Radioactive Waste Management and E-waste
- Solid Waste Management
- Noise Pollution
- Environmental Issues
Biotechnology
Principles of Inheritance and Variation
- Introduction of Principles of Inheritance and Variation
- Mendelism
- Terminology Related to Mendelism
- Mendel’s experiments on pea plant
- Monohybrid Cross
- Gregor Johann Mendel – Father of Genetics
- Punnett Square
- Back Cross and Test Cross
- Mendelian Inheritance - Mendel’s Law of Heredity
- The Law of Dominance
- The Law of Segregation (Law of Purity of Gametes)
- The Law of Independent Assortment
- Intragenic Interactions - Incomplete Dominance
- Intragenic Interactions - Codominance
- Gregor Johann Mendel – Father of Genetics
- Extensions of Mendelian Genetics (Deviation from Mendelism)
- Intragenic Interactions - Incomplete Dominance
- Intragenic Interactions - Dominance
- Intragenic Interactions - Codominance
- Multiple Alleles
- Intragenic Interactions - Pleiotropy
- Polygenic Inheritance
- Chromosomal Theory of Inheritance
- Historical Development of Chromosome Theory
- Comparison Between Gene and Chromosome Behaviour
- Chromosomal Theory of Inheritance: Law of Segregation
- Chromosomal Theory of Inheritance: Law of Independent Assortment
- Linkage and Recombination
- Sex Determination
- Sex Determination in Some Insects
- Sex Determination in Human
- Sex Determination in Birds
- Sex Determination in Honey Bees
- Concept of Mutation
- Pedigree Analysis
- Genetic Disorders
- Mendelian Genetics
- Chromosomal Abnormalities
- Heredity and Variation
- Linkage and Crossing Over
- Principles of Inheritance and Variation Question
Molecular Basis of Inheritance
- Introduction of Molecular Basis of Inheritance
- Deoxyribonucleic Acid (DNA) and Its Structure
- Structure of Polynucleotide Chain
- Packaging of DNA Helix
- Search for Genetic Material
- Introduction of Search for Genetic Material
- The Genetic Material is a DNA
- Properties of Genetic Material (DNA Versus RNA)
- The RNA World
- DNA Replication
- The Experimental Proof
- The Machinery and the Enzymes
- Protein Synthesis
- Introduction of Transcription
- Transcription Unit
- Transcription Unit and the Gene
- Types of RNA and the Process of Transcription
- Genetic Code
- Genetic Code
- Genetic Code
- tRNA – the Adapter Molecule
- Translation
- Regulation of Gene Expression
- Operon Concept
- Human Genome Project
- DNA Fingerprinting Technique
- Structure of DNA and RNA
- Structure of Nucleotide
- Rice Genome Project
- Molecular Basis of Inheritance (Questions)
Ecology
Evolution
- Origin and Evolution of Universe and Earth
- Theories of Origin of Life
- Evolution of Life Forms - a Theory
- Evidences for Biological Evolution
- Theories of Biological Evolution
- Adaptive Radiation
- Organic Evolution
- Hardy Weinberg’s Principle
- Brief Account of Evolution
- Human Evolution
- Darwinism
- Micro and Macro Evolution
- Speciation
- Evolution Stages
- Modern Synthetic Theory of Evolution
- Gene Flow and Genetic Drift
- Evolution
Human Health and Diseases
- Introduction of Human Health and Diseases
- Common Diseases in Human Beings
- Immunity
- Types of Immunity
- Vaccination and Immunization
- Allergies (Hypersensitivity)
- Autoimmunity
- Human Immune System
- Sexually Transmitted Diseases (STD)
- Cancer
- Introduction of Drugs and Alcohol Abuse
- Drugs and Alcohol Abuse
- Adolescence - Drug and Alcohol Abuse
- Addiction and Dependence
- Effects of Drug and Alcohol
- Prevention and Control of Drugs and Alcohol Abuse
- Infectious and Non Infectious Disease
- Maintaining Good Health, Yoga, Excercise
- Human Health and Diseases (Questions)
Strategies for Enhancement in Food Production
Microbes in Human Welfare
- Microbes in Human Welfare
- Microbes in Household Products
- Microbes in Industrial Production
- Microbes in Sewage Treatment
- Microbes in Production of Biogas
- Microbes as Biocontrol Agents
- Microbes as Biofertilizers
- Energy Generation
- Production and Judicious Use
- Microbes in Human Welfare
Biotechnology - Principles and Processes
- Process and Principles of Biotechnology
- Restriction Enzymes
- Cloning Vectors
- Competent Host (For Transformation with Recombinant DNA)
- Processes of Recombinant DNA Technology
Biotechnology and Its Application
Organisms and Populations
- Introduction of Organisms and Populations
- Ecology (Organism, Population, Community and Biome)
- Introduction of Organisms and Environment
- Major Abiotic Factors
- Responses to Abiotic Factors
- Population Attributes
- Population Growth
- Life History Variation
- Population Interactions
- Population and Ecological Adaptations
- Organisms and Populations (Questions)
Ecosystem
- Ecosystem
- Introduction and Types of Ecosystem
- Ecosystem - Structure and Function
- Productivity
- Decomposition
- Concept of Energy Flow in an Ecosystem
- Ecological Pyramids
- Ecological Succession
- Nutrient Cycles
- Ecosystem Services
- Ecosystems Patterns
Biodiversity and Its Conservation
- Biodiversity
- Species on Earth and Species in India
- Patterns of Biodiversity
- Importance of Species Diversity to the Ecosystem
- Loss of Biodiversity
- Conservation of Biodiversity
- Endangered Organisms
- Importance of Biodiversity
- Extinction
- Red Data Book
- Biodiversity and Its Conservation (Questions)
Notes
Sex determination in honey bee:
- In hymenopteran insects such as honeybees, ants, and wasps a mechanism of sex determination called haplodiploidy mechanism of sex determination is common.
- In this system, the sex of the offspring is determined by the number of sets of chromosomes it receives.
- An offspring formed from the union of a sperm and an egg develops as a female (queen or worker), and an unfertilized egg develops as a male (drone) by means of parthenogenesis. This means that males have half the number of chromosomes than that of a female.
- The Sex determination females are diploid having 32 chromosomes and males are haploid, i.e., having 16 chromosomes. This is called as haplodiploid sex-determination system and has special characteristic features such as the males produce sperms by mitosis, they do not have a father and thus cannot have sons, but have a grandfather and can have grandsons.
- This mode of sex determination facilitates the evolution of sociality in which only one diploid female becomes a queen and lays the eggs for the colony.
- All other females which are diploid having developed from fertilized eggs help to raise the queen’s eggs and so contribute to the queen’s reproductive success and indirectly to their own, a phenomenon is known as Kin Selection.
- The queen constructs their social environment by releasing a hormone that suppresses fertility of the workers.
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Haplo-diploid sex determination system |
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