The Science of Biology

What is Biology? Biology: The study of Life!! But… What exactly do we mean by “Life” ?

The 8 Characteristics of Life…

CELLS Unicellular Multicellular All life is made up of cells A cell is the smallest unit that is still considered alive! Unicellular: one cell Multicellular: many cells Unicellular Multicellular

All life can make new life! Reproduction All life can make new life! Asexual=cloning, budding, regeneration Sexual=Sperm and Egg

Based on a UNIVERSAL Genetic Code -Genetic info stored in a molecule called DNA

Growth & Development All organisms grow and Develop Growth: increase in size Development: cells increase in number and become different (differentiate)

Need Materials for Energy All living things use energy: Energy is obtained by breaking down complex “food” molecules Photosynthesis: using light energy to make “food” (sugar). This is the only way energy enters terrestrial food webs Consumption: Must “steal” energy from others Metabolism: combination of chemical reactions through which all organisms build up or break down materials Consumption All living things HAVE METABOLISM! Photosynthesis

Response to the Environment Examples: A plant seed only germinates when there is sufficient water and temperature. Plant roots grow down. Plant leaves grow towards sunlight. Watch this Stimuli Heat Light Pressure Sound Gravity

Maintaining Internal Balance Homeostasis: process by which organisms keep their internal conditions relatively stable Example: How do humans maintain the same body temperature? Sweat Shiver

EVOLUTION To Evolve: To change over time A group of organism can change over many generations leg bone in a whale

The Many Branches of Biology Diversity of life is so great, biology is separated into branches Zoologists: study animals Microbiologists: study bacteria Botanists: study plants Ethologists: study animal behavior Paleontologists: study life from the past Biotechnology is the application and use of knowledge acquired through these and other branches