Biology with Zhang Xuan: IGCSE Biology Series

Overview

• Focus on IGCSE Biology 2023-2028
• New series with reduced study techniques for concise and relevant content
• Chapter 1: Characteristics and Classification of Living Organisms

Introduction

• Renewed series to give comprehensive explanations aligned with the syllabus
• Use of mind maps and study techniques for secondary and tertiary education

Chapter 1 Content

1. Characteristics of Living Organisms
2. Concepts and Uses of Classification Systems
3. Features of Organisms

Characteristics of Living Organisms

• MRS GREN: Mnemonic for:
  • Movement: Action causing position change
  • Respiration: Chemical reactions in cells releasing energy
  • Sensitivity: Detect and respond to environmental changes
  • Growth: Permanent increase in size and mass
  • Reproduction: Making more of the same kind
  • Excretion: Removal of metabolic waste
  • Nutrition: Taking in materials for energy

Concepts and Uses of Classification Systems

• Organisms classified by shared features and DNA
• Species: Organisms that can reproduce fertile offspring
• Classification Sequence: Kingdom > Phylum > Class > Order > Family > Genus > Species
• Binomial Naming System: Genus (capitalized) + Species (not capitalized)
• DNA-based classification for evolutionary relationships

Features of Organisms

• Five Kingdoms: Animals, Plants, Fungi, Prokaryotes, Protists
  • Animals: Multicellular, nucleus, no cell wall/chloroplast, feeds on organic substances
  • Vertebrates: Mammals, reptiles, fish, amphibians, birds
  • Arthropods: Crustaceans, arachnids, myriapods, insects

Classification of Plants

• Ferns: Non-flowering, reproduced by spores
• Flowering Plants: Reproduce sexually/asexually
  • Monocotyledons vs Dicotyledons
    • Monocot: One cotyledon, parallel veins, narrow leaf
    • Dicot: Two cotyledons, branching veins, broad leaf

Viruses

• Not classified as living due to lack of nucleus, mitochondria, ribosomes
• Consist of genetic material and protein coat, require host to replicate

Summary

• Key topics: MRS GREN, classification systems, features of organisms
• Importance of understanding DNA in classification
• Familiarize with Chapter 1 as a foundation

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• Next Steps: Engage with the mind map, understand chapter concepts for future learning
• End of Video: Encouragement to continue with the series