Essential Biology Concepts: Systems, Processes, and Life Sciences

Posted on Jul 26, 2025 in Biology

The Nervous System Fundamentals

Understanding the Reflex Arc

• Know the components: sensory neuron, motor neuron, relay neuron, effector.
• Understand how the reflex arc works.

Neuron Structure and Function

• Describe the structure: axon, dendrites, myelin sheath.
• Explain their role in transmitting nerve impulses.

Synaptic Transmission Explained

• Explain the neurotransmitter role in signal transmission between neurons.

The Human Circulatory System

Heart Anatomy and Blood Flow

• Label a heart diagram and describe the path of blood:
• Right Atrium → Right Ventricle → Pulmonary Artery → Lungs → Left Atrium → Left Ventricle → Aorta.

Role of Heart Valves

• Understand the role of valves in preventing backflow.

Heart Rate Regulation

• Discuss the effect of adrenaline on heart rate.
• Explain control mechanisms during exercise.

Photosynthesis: Life’s Energy Process

The Photosynthesis Equation

• The equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Factors Influencing Photosynthesis

• Temperature
• Light intensity
• CO₂ concentration

Investigating Photosynthesis Rate

• Practical experiment: Investigating light intensity on photosynthesis rate using pondweed.

The Immune System and Immunity

White Blood Cells and Phagocytosis

• Understand the process of phagocytosis.

Antibodies, Antigens, and Memory Cells

• Explain how antibodies target antigens.
• Discuss the role of memory cells in immunity.

Understanding Vaccination

• Describe vaccination: Introduction of dead/weakened pathogens to stimulate antibody production and immunity.

Enzymes and Digestive Processes

Enzyme Action: Lock and Key Model

• Explain the lock and key model.
• Discuss the impact of temperature and pH on enzyme activity.

Key Digestive Enzymes

• Amylase (digests starch)
• Protease (digests protein)
• Lipase (digests lipids)

Enzyme Activity Practical

• Measuring the effect of temperature or pH on enzyme activity (e.g., amylase on starch).

Plant Transport Systems

Root Hair Cells: Water & Mineral Absorption

• Understand adaptations for water/mineral absorption: surface area, active transport.

Factors Affecting Transpiration

• Humidity
• Temperature
• Wind speed

Xylem and Phloem Functions

• Xylem: Water transport
• Phloem: Sugar transport

The Carbon Cycle Explained

Key Carbon Cycle Processes

• Photosynthesis
• Respiration
• Combustion
• Decomposition

Plants’ Role in Carbon Absorption

• Explain the absorption of CO₂ by plants during photosynthesis.

The Human Respiratory System

Gas Exchange in Alveoli

• Describe oxygen and CO₂ exchange in the alveoli.
• Note features: thin walls, large surface area.

Mechanism of Breathing

• Explain the role of the diaphragm and intercostal muscles in inhalation and exhalation.

Animal Transport Systems

Blood Components and Functions

• Function of: red blood cells, white blood cells, platelets, plasma.

Arteries Versus Veins

• Structural differences: thick walls, valves, lumen size.
• Functions of arteries and veins.

Ecology: Interconnected Systems

Food Chains and Food Webs

• Understand energy transfer: producers, consumers.

Biomass and Energy Transfer in Ecosystems

• Explain how energy decreases with higher trophic levels.

Movement of Substances in Biology

Understanding Diffusion

• Movement of particles from high to low concentration (e.g., oxygen into cells).

Osmosis and Cell Structure

• Water movement across a semipermeable membrane.
• Impact on cell structure.

Active Transport Explained

• Movement against concentration gradient using energy (e.g., root hair cells).

Genetics and Inheritance Principles

DNA Structure: The Double Helix

• Describe double helix, nucleotides, base pairing (A-T, C-G).

Mendelian Inheritance Patterns

• Understand dominant and recessive alleles.
• Calculate genotypic/phenotypic ratios (using Punnett squares).

Sex Determination in Humans

• Explain X and Y chromosomes (XX=female, XY=male).

Common Genetic Disorders

• Examples: Cystic fibrosis, Huntington’s disease.

Natural Selection and Evolution

Darwin’s Theory of Evolution

• Key concepts: variation, competition, survival of the fittest.

Speciation: Formation of New Species

• Explain geographic isolation leading to new species.

Biological Adaptations

• Types of adaptations: behavioural, physiological, and structural (e.g., camels in deserts).

Plant and Animal Cell Biology

Prokaryotic vs. Eukaryotic Cells

• Differences in structure (e.g., no nucleus in prokaryotes).

Key Cell Organelles and Functions

• Mitochondria (energy)
• Chloroplasts (photosynthesis)
• Vacuoles (storage)

Microscopy Techniques for Cells

• Techniques to view cells: slide preparation, magnification.

Human Impact on the Environment

Environmental Pollution Effects

• Air pollution and its effects on ecosystems.

Impact of Deforestation

• Impact on biodiversity and climate.

Global Warming and Greenhouse Gases

• Understand greenhouse gases and human activities.

Conservation Strategies

• Strategies like national parks, seed banks, breeding programs.

Bioenergetics: Energy in Living Systems

Aerobic vs. Anaerobic Respiration

• Differences in energy production and byproducts (e.g., lactic acid in anaerobic).

Energy Transfer and Oxygen Debt

• Explain oxygen debt and repayment after exercise.

Variation and Adaptation in Organisms

Genetic vs. Environmental Variation

• How both contribute to organism diversity.

Continuous vs. Discontinuous Variation

• Differences (e.g., height vs. blood group).

Selective Breeding Process

• Process of breeding for specific traits in animals/plants.

Sustainable Use of Biological Resources

Farming Practices and Their Impacts

• Fertilizers, pesticides, herbicides, and their impacts.

Genetically Modified Organisms (GMOs)

• Discuss the pros and cons in food production.

Biological Pest Control

• Use of natural predators/parasites for pest control.