SIMPLY BIOLOGY STUDY NOTES

Preface

  • The author of this book aimed to contribute to Zambia's educational system.
  • Initial material derived from notes used for teaching Senior Secondary School Biology.
  • Student success in Zambian and International examinations validated the content.
  • A first manuscript was produced in 2006, with input from students and the editing support from experienced examiners.

Acknowledgements

  • The author thanks:
    • Shawn Banda and Zameer for typing parts of the work.
    • Former students for testing the material and providing feedback.
    • Mr. Severian Masesa for editing expertise.

Introduction: What is Biology?

  • Definition: Biology is the study of living organisms.
  • Branches of Biology:
    • Botany: Study of plants.
    • Zoology: Study of animals.
    • Ecology: Interactions between organisms and their environment.
    • Biochemistry: Chemical processes in living organisms.
    • Entomology: Study of insects.

1. LIVING ORGANISMS

1.1 Characteristics of Living Organisms
  • Use the mnemonic MR. GREFIC:
    • Movement
    • Respiration
    • Growth
    • Reproduction
    • Excretion
    • Feeding
    • Irritability (sensitivity to stimuli)
    • Cells (made of one or more cells)
Movement
  • Change of location or posture without external help.
  • Locomotion is when the entire organism moves from one place to another.
Respiration
  • Definition: Energy release from food inside living cells.
  • Types:
    • Aerobic (with oxygen)
    • Anaerobic (without oxygen; less energy released)
Growth
  • Definition: Permanent increase in size, mass, or number of cells.
Reproduction
  • Definition: Process of producing offspring.
  • Types:
    • Sexual: offspring genetically different (fusion of gametes).
    • Asexual: offspring identical to parent (no gametes).
Excretion
  • Definition: Removal of toxic metabolic wastes (e.g., urea, CO₂).
Feeding/Nutrition
  • Types:
    • Autotrophic: Organisms (e.g. green plants) make their own food.
    • Heterotrophic: Organisms obtain food from others.
Irritability/Sensitivity
  • Ability to respond to stimuli (changes in the environment).
Cells
  • Basic unit of life; can be unicellular (e.g. bacteria) or multicellular (e.g. plants, animals).
1.2 Cell Structure, Cell Specialization, Tissues, Organs, Systems and Organisms
  • Cells: Basic functional unit.
    • Animal Cells: No cell wall, smaller vacuoles, no chloroplasts.
    • Plant Cells: Cell wall present, one large central vacuole, chloroplasts.
  • Cells undergo specialization to perform specific functions (e.g. muscle cells, neurones).
  • Tissues: Group of similar cells working together (e.g. muscle tissue).
  • Organs: Collection of tissues (e.g. heart).
  • Systems: Group of organs working together (e.g. circulatory system).
  • Organism: Total living entity (e.g. human body).
1.3 Transport across Cell Membranes: Diffusion, Osmosis and Active Transport
  • Diffusion: Movement from high to low concentration.
    • Factors affecting diffusion: concentration gradient, temperature, surface area.
  • Osmosis: Movement of water through a selectively permeable membrane.
    • Types of solutions:
    • Hypotonic: Lower solute concentration (cell swells).
    • Isotonic: Equal solute concentration (cell remains constant).
    • Hypertonic: Higher solute concentration (cell shrinks).
  • Active Transport: Movement against concentration gradient using energy (ATP).
1.4 Enzymes
  • Definition: Biological catalysts that speed up chemical reactions.
  • Characteristics:
    • Proteins in nature.
    • Specificity (act on specific substances; lock and key model).
    • Affected by temperature, pH, substrate concentration, etc.
  • Examples:
    • Amylase (acts on starch), Protease (acts on proteins).
1.5 Classification of Living Organisms
  • Taxonomy: Classification based on shared features.
    • Categories: Kingdom, Phylum, Class, Order, Family, Genus, Species.
  • Nomenclature: Scientific naming system (binomial).
  • Five Kingdoms:
    • Prokaryota (bacteria)
    • Protoctista (protozoa, algae)
    • Fungi (yeasts, molds)
    • Plantae (plants)
    • Animalia (animals)

2. DRAWING, MEASURING AND MAGNIFICATION

2.1 Drawing
  • Ensure that the drawing is clean, labelled, and proportionate.
2.2 Measuring
  • Measurements must be accurate and specific, recorded properly.
2.3 Magnification
  • Definition: Ratio of image size to actual size.
  • Formula: extMagnification=extsizeofdrawingextactualsizeext{Magnification} = \frac{ ext{size of drawing}}{ ext{actual size}}

3. NUTRITION

3.1 Types of Nutrition and Nutrients
3.1.1 Modes of Nutrition
  • Autotrophic: Organisms create their own food.
  • Heterotrophic: Organisms depend on others for food.
3.1.2 Nutrients: Types, Sources, Uses and Tests
  • Carbohydrates, Proteins, Fats, Vitamins, Minerals, Water.
3.2 Nutrition in Plants
3.2.1 Photosynthesis
  • Process by which plants make food using sunlight.
3.2.2 Mineral Nutrition in Plants
  • Essential minerals for plant growth.
3.3 Nutrition in Animals
3.3.1 The Alimentary Canal and Associated Organs
  • Structure and function of digestive organs.
3.3.2 Digestion and Assimilation of Nutrients
  • Breakdown of food and nutrient uptake.
3.3.3 Common Ailments of the Alimentary Canal
  • Disorders such as diarrhea and constipation.
3.3.4 Functions of the Liver
  • Metabolic regulator, detoxification, nutrient storage.
3.3.5 Common Ailments of the Liver
  • Conditions like hepatitis and cirrhosis.
3.3.6 Dentition
  • Types and function of teeth.

4. TRANSPORT

4.1 Transport in Flowering Plants
4.1.1 The Vascular System
  • Role of xylem and phloem in transport.
4.1.2 Absorption of Water and Minerals
  • Mechanism of nutrient uptake.
4.1.3 The Transpiration Stream
  • Process of water movement through plants.
4.1.4 Transpiration
  • Water loss through stomata.
4.1.5 Translocation
  • Movement of food through phloem.
4.2 Transport in Animals
4.2.1 The Blood Circulatory System
  • Structure and function of the heart and blood vessels.
4.2.1.1 The Heart
  • Anatomy and function of the heart.
4.2.1.2 Blood Vessels
  • Different types and their roles.
4.2.1.3 Blood: Composition, Functions, Groups
  • Elements of blood and their functions.
4.2.1.4 Blood Disorders
  • Common diseases (e.g., anemia).
4.2.2 The Lymphatic System
  • Role in immune response and fluid balance.

5. RESPIRATION

5.1 Breathing and Gaseous Exchange
  • Mechanism across various organisms.
5.2 Gaseous Exchange in Green Plants
  • Oxygen and carbon dioxide exchange via stomata.
5.3 Composition of Inspired and Expired Air
  • Difference in gas concentrations.
5.4 Effects of Pollution on Gaseous Exchange
  • How pollutants impact respiratory function.

6. EXCRETION

6.1 Excretion in Plants
  • How plants remove waste products.
6.2 Excretion in Human Beings
  • Overview of waste removal systems.
6.3 The Kidney
  • Structure and function in excretion.
6.4 The Lungs
  • Role in gas exchange and waste removal.
6.5 The Skin
  • Mechanism of waste removal through sweat.

7. HOMEOSTASIS

7.1 Types of Homeostasis
  • Thermoregulation, osmoregulation, etc.
7.2 Important Organs
  • Liver, skin, kidneys in maintaining homeostasis.
7.3 Skin's Role in Thermoregulation
  • Mechanisms for temperature control.
7.4 Liver's Role
  • Managing blood sugar and metabolic processes.

8. GROWTH AND DEVELOPMENT

8.1 Growth in Plants
8.1.1 Types of Growth
  • Primary and secondary growth.
8.1.2 Regions of Growth
  • Meristems and regions of active growth.
8.1.3 Germination and Development
  • Factors affecting seed sprouting.
8.2 Growth in Houseflies and Mosquitoes
  • Lifecycle and development of insects.

9. RESPONSES AND COORDINATION

9.1 Tropic and Taxic Responses
  • Differences in plant vs. animal responses.
9.2 The Endocrine System
  • Hormonal coordination in human physiology.
9.3 Nervous Systems
  • Structure and function of the nervous system.
9.4 Sense Organs
  • Functions and structures of key sensory organs.

10. LOCOMOTION

10.1 Skeletons
10.1.1 Types of Skeletons
  • Hydrostatic, exoskeletons, and endoskeletons.
10.1.2 The Insect Skeleton
  • Structure and adaptation.
10.1.3 The Mammalian Skeleton
  • Overview of human skeletal system.
10.2 Muscles and Joints
  • Types of muscle tissue and joint structures and functions.

11. REPRODUCTION

11.1 Types of Reproduction
  • Differences between sexual and asexual reproduction.
11.2 Reproduction in Plants
  • Mechanisms, flowers, and pollination.
11.3 Reproduction in Animals
  • Overview of reproductive systems and processes.

12. HEALTH AND DISEASE

12.1 Good Health Versus Disease
  • Definitions and parameters of health status.
12.2 Types of Diseases
  • Infectious vs. non-infectious diseases.
12.3 Ailments and Conditions
  • Overview of diseases like AIDS, cholera, malaria, and bilharzia.
12.4 Immunity
  • Body’s ability to resist infection and its types.

13. GENETICS

  • Overview of inheritance mechanisms through examples.
13.1 Variation
  • Definitions and examples of continuous and discontinuous variation.
13.2 Chromosomes and Genes
  • Structure and action.
13.3 Cell Division
  • Mitosis vs. meiosis, importance, and types.
13.4 Monohybrid Inheritance
  • Example and genetic diagram explanation.
13.5 Blood Group Inheritance
  • ABO blood types and genetics.
13.6 Sex Inheritance
  • Chromosomal role in heredity.
13.7 Sex Linkage
  • Explanation and examples of genetic conditions.
13.8 Mutations
  • Causes and effects of genetic mutations.
13.9 Selection
  • Natural selection and its evolutionary significance.
13.10 Genetic Engineering
  • Overview of gene transfer processes.

14. ECOLOGY

14.1 Ecosystem Concepts
  • Definitions and components of ecosystems.
14.2 Energy Flow
  • The role of producers, consumers, and decomposers.
14.3 Food Chains and Webs
  • Details of organism interactions and energy transfer.
14.4 Ecological Pyramids
  • Types of pyramids and their interpretations.
14.5 Nutrient Cycles
  • Processes involving nutrient transfer.
14.6 Effects of Human Activity
  • Discussion on pollution, deforestation, and mitigation strategies.
14.7 Population Dynamics
  • Growth patterns and influencing factors in populations.
14.8 Biodiversity
  • The importance and impact of species diversity in ecosystems.