What is life?

The characteristics of living things Six characteristics that all living things share Have cellular organization Contain similar chemicals Use energy Respond to their surroundings Grow and develop Reproduce

Cellular Organization The cell is the basic unit of all living things Unicellular = one cell Multicellular = more than one cell

The chemicals of life The cells of all living things are composed of chemicals Water is the most abundant chemical Carbohydrates Lipids Proteins Nucleic acids

Energy Use Cells need energy to work We get energy by eating food. We are consumers or heterotrophs How do plants get energy? Fungi?

Response to Surroundings Stimulus Change in surroundings Response Action or change in behavior

Growth and Development Growth is the process of becoming larger Development is becoming more complex

Life comes from Life Living things come from living things through reproduction Spontaneous generation Mistaken idea that living things can come from non living sources Francesco Redi showed that flies do not come from decaying meat Louis Pasteur used a controlled experiment to show that bacteria do not arise from boiled broth

What did Redi change? This is called the Independent variable

What was the Independent variable in Pasteur’s experiment?

The needs of living things Water-cannot survive long without Needed in order to Obtain chemicals from surroundings Break down food Grow Move substances within bodies Reproduce Food-for energy Autotrophs make their own food Heterotrophs cannot make their own food Living Space Stable internal conditions-Homeostasis Needed for cells to function What happens when you get too hot?