BIO 1 A Unit 1 MR HANCZYC Goal

BIO 1 A – Unit 1 MR. HANCZYC

Goal of Science The goal of science is to: • investigate and understand the natural world. • explain events in the natural world. • use those explanations to make useful predictions. Science is an organized way of using evidence to learn about the natural world.

Science 1. Science deals only with the NATURAL WORLD. 2. Scientists collect and organize information in a careful, orderly way, looking for patterns and connections 3. Scientists propose explanations that can be tested by examining evidence / data

Scientific Process Scientific thinking begins with observation. Observation is the process of gathering information about events or processes in a careful, orderly way. Example:

Scientific Process Data - the information gathered from observations is called. Quantitative data are expressed as numbers, obtained by counting or measuring. Qualitative data are descriptive and involve characteristics that can’t easily be measured.

Scientific Process Scientists use data to make inferences. Inference is a logical interpretation based on prior knowledge or experience.

Scientific Process Scientists use inferences to form hypotheses that can be tested. A hypothesis is a proposed scientific explanation for a set of observations. A hypothesis may be ruled out or confirmed.

Scientific Process A hypothesis must be proposed in a way that can be tested. Hypotheses are tested by performing controlled experiments or by gathering new data. To be valid, a conclusion must be based on logical interpretation of reliable data reviewed by other scientists.

Scientific Method 1. Ask a question. 2. Form a hypothesis. 3. Design a controlled experiment 4. Record analyze results. 5. Draw conclusions.

Designing an experiment Independent Variable (manipulated variable) - the variable that is deliberately changed by the experimenter. Dependent Variable (responding variable) – the variable that changes in response to the independent variable. ◦ Ex. How does the amount of fertilizer affect plant growth over time? (graphing) ◦ Independent Variable – ◦ Dependent Variable -

Designing an experiment Where do organisms come from? ◦ Sources of life? ◦ Spontaneous generation? ◦ Other explanations? Form a hypothesis.

Designing an experiment

Analyzing Results / Drawing Conclusions Redi’s Experimental Results: ◦ Maggots only form when flies contact the meat. ◦ Spontaneous generation did not occur. Redi’s results supported the hypothesis that maggots were produced by flies, not spontaneous generation.

Repetition in Science Experiments are often repeated by other scientists to prove validity. ◦ Spallanzani and Pasteur improved and repeated Redi’s experiment to further prove that spontaneous generation does not occur.

Spallanzani's Test of Redi's Findings

Pasteur’s Experiment

Levels of Organization Some of the levels at which life can be studied include: • organism • populations • communities • ecosystems • biomes • biosphere

Levels of Organization

Levels of Organization Cell – the smallest functional unit of life Tissue – group of similar cells Organ – group of similar tissues Organ System – group of similar organs Organism -

Levels of Organization

Safety Working Safely in Biology ◦ Scientists working in a laboratory or in the field are trained to use safe procedures. Laboratory work may involve contact with dangerous materials or organisms.

Safety Follow safe practices. • Study the safety rules. • Read all the steps and safety precautions. • Follow your teacher’s instructions and textbook directions exactly. • If in doubt, ask your teacher for an explanation. • Wash your hands thoroughly with soap and warm water after every scientific activity.

Metric System