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In-Depth Notes on Classification, Biodiversity, and Related Concepts

Classification and Biodiversity

Classification - Descriptive Groups

  • Definition: Classification means organizing living organisms into groups based on similarities.

  • Main Groups:

    • Plants: Includes:

    • Flowering plants (e.g., those that produce flowers)

    • Non-flowering plants (e.g., ferns and mosses)

    • Animals: Divided into:

    • Vertebrates (with backbone)

    • Invertebrates (without backbone, e.g., insects)

Importance of Classification

  • Classification helps understand:

    • The variety of living organisms

    • Evolutionary relationships and changes over time

Classification Systems

  • Five Kingdom Classification based on morphological features:

    1. Bacteria: Single-celled organisms

    2. Plants

    3. Fungi

    4. Animals

  • Common names for organisms can be misleading as they are often based on appearance.

Naming Organisms

  • Scientific Naming: Uses a binomial naming system by Carl Linnaeus; names are in Latin.

    • Each organism is given a two-part name (Genus and species), e.g., Homo sapiens (humans), Erinaceus europaeus (hedgehog).

Example of Classification

Organism

Domestic Dog

Coyote

Fox

Kingdom

Animalia

Animalia

Animalia

Phylum

Chordata

Chordata

Chordata

Class

Mammalia

Mammalia

Mammalia

Order

Carnivora

Carnivora

Carnivora

Family

Canidae

Canidae

Canidae

Genus

Canis

Canis

Vulpes

Species

lupus

latrans

vulpes

Adaptations

  • Organisms develop morphological and behavioral adaptations for survival.

    • Example - Foxes:

    • Arctic Fox: Found in Arctic, has a thicker coat for insulation.

      • Features:

      • Body mass: 6.5-17.0 kg

      • Coat color: White in winter

    • Fennec Fox: Found in deserts with a sandy cream coat for camouflage.

      • Features:

      • Ear length: 10-15 cm (larger ears help in heat loss)

Population Size

  • Definition: The number of individuals of a particular species in an ecosystem.

  • Influenced by:

    • Competition for food and water

    • Number of predators

    • Disease and pollution

Biodiversity

  • Definition: Variety of different species in an area and the number of individuals within those species.

  • Importance of biodiversity includes food resources, potential foods, industrial materials, new medicines, and overall human well-being.

Protecting Endangered Species

  • Methods of Protection:

    • CITES: Prevents trade in endangered species.

    • SSSIs: Protects rare habitats or species.

    • Captive Breeding Programs: Increase numbers of rare species for re-introduction.

    • National Parks: Protects areas due to natural beauty and biodiversity.

    • Seed Banks: Maintains genetic diversity of plants.

    • Local Conservation Schemes: Initiatives by local authorities to enhance biodiversity.

Studying Ecosystems

  • Methods for assessing species populations often involve sampling techniques.

    • Quadrat Sampling: Used to assess plant populations.

    • Transects: Used to study distribution of species in a habitat.

Measuring Movement in Animal Populations

  • Capture-Recapture Method: Assesses the population by marking and recapturing animals, following a formula:
    N = rac{MC}{R}

  • Where:

    • N = total population estimate

    • M = marked individuals captured first

    • C = individuals captured second

    • R = recaptured marked individuals in second sample.

Biological Control of Pests

  • Definition: Using natural predators/parasites to manage pest populations.

  • Example: Use of wasps to control whitefly in greenhouses, offering a targeted approach without harming beneficial insects.

Alien Species

  • Definition: Organisms introduced into new environments where they are not native; may disrupt ecosystems.

  • Example: Japanese knotweed, an invasive species in Britain, poses significant ecological risks due to lack of natural predators.

Cell Division and Stem Cells

Overview of Cell Division

  • Cells divide for growth and reproduction.

  • Mitosis vs. Meiosis:

    • Mitosis: Produces 2 identical cells for growth/repair.

    • Meiosis: Produces 4 genetically varied gametes (sperm/eggs).

Mitosis Explained

  • Occurs in somatic cells. Each new cell maintains the original chromosome number (e.g., humans have 46 chromosomes).

Meiosis Explained

  • Occurs in germ cells, reducing chromosome number by half, leading to genetic diversity through recombination.

Stem Cells

  • Definition: Undifferentiated cells capable of turning into other cell types.

  • Sources:

    • Adult Stem Cells: Found in tissues (e.g., bone marrow).

    • Embryonic Stem Cells: Derived from fertilized embryos.

  • Uses: Potential for medical treatments (e.g., repairing damaged tissue).

DNA and Inheritance

Structure of DNA

  • DNA is structured as a double helix composed of sugar, phosphate, and bases (A, T, C, G).

  • Base pairing rules: A-T, C-G.

Genetic Profiling

  • Used to compare genetic similarities among individuals.

  • Applications in forensic science, paternity cases, and disease studies.

Patterns of Inheritance

  • Terms to remember: gene, allele, genotype, phenotype, dominant/recessive traits.

  • Example: Pea plants studied by Gregor Mendel demonstrate basic principles of inheritance via Punnett squares.

Response and Regulation

The Nervous System

  • Comprised of receptors, neurones, and the brain; it processes stimuli and coordinates responses.

  • Reflex Actions: Fast, automatic reactions to stimuli; involve a reflex arc.

Homeostasis

  • Maintaining stable internal conditions (e.g., temperature, glucose levels).

  • Roles of Hormones: Insulin for blood sugar regulation, ADH for water balance.

Diabetes

  • Type 1: Insulin deficiency; Type 2: Insulin resistance. Management includes lifestyle adjustments and medications.

Role of the Kidneys in Homeostasis

Kidney Functions

  • Maintaining water balance, filtering waste products from blood.

  • Structure: Includes renal artery, renal vein, nephrons (functional unit).

Nephron Functioning

  • Ultrafiltration: Filters blood under pressure to form urine.

  • Reabsorption: Useful substances like glucose and water are reabsorbed back into circulation.

Treatments for Kidney Failure

  • Dialysis: Filters blood artificially when kidneys fail.

  • Transplant: Replacing a failed kidney with a healthy one.

Micro-organisms and Their Applications

Bacteria Growth

  • Techniques for culturing bacteria include using aseptic methods to prevent contamination.

Antibiotics

  • Used to treat bacterial infections but ineffective against viruses.

  • Antibiotic Resistance: Can develop from overprescribing or misuse of antibiotics.

Disease, Defence and Treatment

Immune Response

  • Body has multiple defenses against pathogens, including skin barrier and white blood cell activities.

  • Vaccination: Introduces antigens to build immunity against diseases by stimulating antibody production.

Monoclonal Antibodies

  • Produce specific antibodies used for diagnosis and treatment of diseases.

  • Applications include cancer therapy, diagnostics, and disease monitoring.