🧬 Biology as a Science
Methods of Biology — Grade 9
🔬 What Is Biology?
Biology is the science that studies life. The word comes from the Greek bios (life) and logos (study).
Biology is an incredibly broad science. It spans from the tiniest molecules inside your cells all the way to the entire biosphere — every ecosystem on Earth. To study something so vast, biologists rely on systematic methods to ask questions, gather evidence, and build reliable knowledge.
🌱 Characteristics of Life
All living organisms share several key characteristics. When viewed together, these characteristics serve to define life:
Order
All living things are made of cells, the smallest fundamental unit of life, organized in structured ways.
Sensitivity
Response to stimuli — organisms detect and react to changes in their environment.
Reproduction
The ability to produce new organisms, either sexually or asexually.
Adaptation
Populations evolve traits that help them survive in their environments over generations.
Growth & Development
Organisms grow and develop following specific genetic instructions.
Regulation
Internal processes are controlled and coordinated (e.g., gene expression, hormones).
Homeostasis
Maintaining a stable internal environment (e.g., body temperature at ~37°C).
Energy Processing
All organisms use energy — through photosynthesis, cellular respiration, or consuming food.