Lecture Notes on Cambridge IGCSE Biology Paper (0610/31)

Overview

• Course: Cambridge IGCSE Biology 0610/31
• Exam Details: Paper 3 Theory (Core), May/June 2024
• Duration: 1 hour 15 minutes
• Total Marks: 80
• Instructions: Use black/dark blue pen, calculators allowed, show all working with units.

Breadmaking and Microorganisms

Breadmaking

• Gas Causing Dough Rise: Carbon Dioxide
• Process in Yeast: Fermentation
• Product Made Using Yeast (Non-food/drink): Industrial alcohol

Bacteria in Biotechnology

• Useful Characteristics:
  • Make complex molecules
  • Have a rapid reproduction rate

Characteristics of Living Organisms

• Ability to Detect and Respond: Sensitivity
• Removal of Waste Products: Excretion
• Increase in Size and Mass: Growth
• Common Cell Structures (Bacteria & Plants): Cell wall and ribosomes

Enzymes

Definition and Nature

• Catalyst: Substance that increases the rate of a chemical reaction without undergoing permanent change
• Biological Molecule of Enzymes: Proteins

Enzyme Activity

• Temperature Effects:
  • Enzyme A: Optimal at a lower temperature
  • Enzyme B: Optimal at a higher temperature
• Enzyme Structure: Active site has a complementary shape to substrate
• Factors Affecting Enzyme Activity: pH, substrate concentration

Role in Metabolism

• Functions of Enzymes:
  • Involved in all metabolic reactions
  • Necessary to sustain life
  • Used in making food products like fruit juice

Diffusion and Respiration

Diffusion Experiment

• Surface Area Effect on Diffusion: Higher surface area increases rate of diffusion
• Factors Affecting Diffusion: Concentration gradient

Osmosis vs. Diffusion

• Osmosis Difference: Only involves water across a semi-permeable membrane

Respiration

• Substances Needed: Glucose and oxygen
• Location of Aerobic Respiration: Mitochondria
• Cell Entry Point: Cell membrane

Disease Prevention

Hygiene and Disease Control

• Handwashing After Sneezing: Prevents transmission of pathogens
• Waterborne Disease Prevention: Clean water supply, sewage treatment

Body Defenses Against Disease

• Mechanisms:
  • Skin barrier
  • Immune response
  • Mucus and ciliary action

Disease Transmission

• Transmissible Diseases: HIV
• Nontransmissible Diseases: Coronary heart disease, scurvy

Plant Growth and Tropic Responses

Germination Conditions

• Oxygen Requirement: Tubes without oxygen show no germination
• Ideal Seed Storage: Cold and dry conditions

Tropic Responses

• Light Response in Plants: Plant X shows phototropism towards light
• Advantage of Tropic Responses: Helps in maximizing light absorption

Plant Position in Food Chain

• Position: Primary producers

Habitat and Biodiversity

Habitat Destruction

• Reasons: Urbanization, resource extraction, deforestation

Monoculture Advantages

• Benefits:
  • Efficient large-scale farming
  • Easier pest control
  • Uniform crop management

Conservation Strategies

• Methods: Captive breeding, seed banks

Biodiversity

• Definition: Variety of life in the world or in a particular habitat/ecosystem

Sustainable Resource Use

• Firewood Management: Controlled harvesting, replanting

Human Digestive System

Organ Identification

• Gall Bladder: B
• Salivary Amylase Secretion: F
• Egestion Site: G
• Absorption Site: D
• Physical Digestion Site: C
• Acidic pH Location: A

Nutrient-Molecule Links

• Fat: Contains glycerol
• Protein: Contains amino acids

Vitamin and Mineral Importance

• Vitamin Deficiency (Rickets): Lack of Vitamin D
• Calcium: Bone health
• Iron: Oxygen transport

Balanced Diet Components

• Additional Components: Carbohydrates, fiber

This summary covers the key topics and details covered in the Biology Paper 3 theory for Cambridge IGCSE, focusing on microorganisms, enzymes, diffusion, disease prevention, tropic responses, habitat conservation, and human digestion.