1.3 Scientific Thinking and Processes KEY CONCEPT Science is a way of thinking, questioning, and gathering evidence.

1.3 Scientific Thinking and Processes Like all science, biology is a process of inquiry. Scientists make careful and systematic observations. Scientists test their hypotheses and analyze their data. Take data from experiment and look at trends. What does it mean? Is my hypothesis supported? Propose new experiments. Scientists form a hypothesis as a possible answer to a question. Scientists record observations as data. Create an experiment What you think will happen based on your observations.

1.3 Scientific Thinking and Processes Biologists use experiments to test hypotheses. Observational studies allow scientists to describe a phenomenon.

1.3 Scientific Thinking and Processes Experimentals allow scientists to determine what causes a phenomenon.

1.3 Scientific Thinking and Processes –Independent variables are manipulated. –Constants are conditions that are kept the same. Experimental studies allow scientists to determine what causes a phenomenon. –Dependent variables are observed and measured. Y-axis

1.3 Scientific Thinking and Processes A theory explains a wide range of observations. Theories explain a wide range of observations and experimental results. A theory is supported by a wide range of scientific evidence. Theories can change based on new evidence.

1.3 Scientific Thinking and Processes KEY CONCEPT Section 4 Technology continually changes the way biologists work.

1.3 Scientific Thinking and Processes Imaging technologies provide new views of life. A microscope provides an enlarged image of an object. stoma –light microscopes (LM)- specimen is or can be alive

1.3 Scientific Thinking and Processes stoma – scanning electron microscopes (SEM) enlarged outside detail of an object that is not alive but is in 3-D Imaging technologies provide new views of life. A microscope provides an enlarged image of an object. –light microscopes (LM)

1.3 Scientific Thinking and Processes –transmission electron microscopes (TEM) – cuts a cross section (slice) out of the object. The object is dead, extremely detailed and in 2-D stoma – scanning electron microscopes (SEM) Imaging technologies provide new views of life. A microscope provides an enlarged image of an object. –light microscopes (LM)

1.3 Scientific Thinking and Processes Imaging technology is used in medicine. –X-ray images – shows bones because it passes through the soft tissue only and is absorbed by bone (teeth too)

1.3 Scientific Thinking and Processes –magnetic resonance imaging (MRI)- uses strong magnetic field to produce a cross section image of a part of the body. Imaging technology is used in medicine. –X-ray images

1.3 Scientific Thinking and Processes –functional MRI (fMRI)- Can show areas of the brain that are active while a person is doing a task. –magnetic resonance imaging (MRI) Imaging technology is used in medicine. –X-ray images

1.3 Scientific Thinking and Processes Complex systems are modeled on computers. Computer models are used to study systems that cannot be studied directly. –heart attacks –effect of medicines on the human body –movement of water molecules into and out of a cell –spread of a disease through a population Computer models are used when experiments are not safe, ethical, or practical.(cannot be studied directly) Normal heartbeat Heart attack

1.3 Scientific Thinking and Processes The tools of molecular genetics give rise to new biological studies. A gene is a segment of DNA that stores genetic information.

1.3 Scientific Thinking and Processes Through our understanding of DNA, we can study genetics on a molecular level. –molecular genetics- the study of and manipulation of DNA on a molecular level. –Genomics – the study and comparison of genomes both within and across a species.