The Nature of Life Ch. 1

What is Science? The goal of science is to investigate and understand nature, to explain events in nature, and to use those explanations to make useful predictions. Science – an organized way of using evidence to learn about the natural world. Observation – involves using one or more of the senses – sight, hearing, touch, smell, and sometimes taste to gather information. Data – the information gathered from observations Inference – a logical interpretation based on prior knowledge and experience. Hypothesis – a possible explanation for a set of observations or an answer to a scientific question.

When a hypothesis has been tested many times and has never been disproven, it becomes a Theory.

Controlled Experiments Experimental Variables Manipulated (Independent) vs. Responding (Dependent)

Jack wants to find out which laundry detergent cleans the best Jack wants to find out which laundry detergent cleans the best. So, he takes a cotton sheet and cuts it up into equal squares. He stains four squares with chocolate, and four with grape juice. He washes one of each of the squares in each of the 3 detergents. One from each set of squares is washed in water alone. For each wash load, he used: the same amount of water, the same amount of detergent, and the same water temperature. Independent Variable: Dependent Variable: Control(s): Constants: Hypothesis:

Characteristics of Living Things Are made of Cells (a collection of living matter enclosed by a barrier) Reproduce either by sexual or asexual reproduction Are based on a universal genetic code Grow and Develop Obtain and use materials and energy (metabolism) Respond to their environment Maintain a stable internal environment (homeostasis) Change over time (evolve)