Biology Key Concepts


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Biology Key Concepts

What is the goal of science? The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions.

How do scientists test hypotheses? Whenever possible a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled.

How does a scientific theory develop? In science the word theory applies to a well tested explanation that unifies a broad range of observations.

What are some characteristics of living things? Living things follow the same characteristics. Made up of units called cells, they reproduce, based on a universal genetic code, they grow and develop, they obtain and use materials and energy, they respond to their environment, they maintain a stable internal environment, as a group, they change over time.

How can life be studied at different levels? Some of the levels at which life can be studied include molecules, cells organisms, populations of a single kind of organism, communities of different kinds of organisms in an area, and the biosphere. At all these levels smaller living systems are found within larger systems.

What measurement system do most scientists use? Most scientists use the metric system when collecting data and performing experiments.

How are light and electron microscopes similar and different? Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magnified images by focusing beams of electrons.