2. Living Systems

3. Chapter One: Studying Life 1.1 Measurements 1.2 Thinking Like a Scientist 1.3 Graphs

4. Investigation 1A Is there a relationship between human “wingspan” and height? ¿Existe una relación entre el ser humano "envergadura" y la altura? Measurement and Data De medición y datos

5. 1.1 Measurement and Data A measurement is a value that tells the amount of something. A measurement has a quantity and a unit. Una medida es un valor que indica la cantidad de algo. Una medida tiene una cantidad y una unidad. How do we measure tiny living things?

6. 1.1 Measurement and Data A unit is a fixed amount of something. Una unidad es una cantidad fija de algo. The centipede below is 5 centimeters (5 cm.) in length. The earthworm is 5 inches (5 in.) in length. Which is a larger unit, centimeters or inches?

7. 1.1 International System of Measurement Units allow people to communicate amounts. To make sure their measurements are accurate, scientists use a set of standard units that have been agreed upon around the world. The International System of Measurement is known as the S.I. (System International). El Sistema Internacional de Medición que se conoce como el SI (Sistema Internacional).

8. 1.1 Length Length is a measurement of distance. La longitud es una medida de distancia. How should we measure the length of this fish?

10. 1.1 Area Area is a measurement of how much surface something has. Área es una medida de la cantidad de superficie algo tiene.

11. 1.1 Volume Volume is a measurement of the amount of space something occupies. El volumen es una medida de la cantidad de espacio en algo que ocupa.

12. 1.1 Measuring Liquids The surface of a liquid forms a curve rather than a straight line. La superficie de un líquido forma una curva en lugar de una línea recta. That curve is called a meniscus. If the meniscus curves downward, read the volume at the bottom of the curve.

13. 1.1 Mass Mass is the measure of the amount of matter that makes up something. La masa es la medida de la cantidad de materia que compone algo.

14. 1.1 Temperature Temperature is a measure of how hot or cold something is. La temperatura es una medida de qué tan caliente o frío. As particles move faster on average, the temperature goes up. As particles move slower on average, the temperature goes down.

15. 1.1 Measuring Solutions A solution is a mixture of two or more substances that are evenly distributed at the molecular level. Una solución es una mezcla de dos o más sustancias que se distribuyen uniformemente en el nivel molecular. Scientists use units of concentration when measuring levels of dissolved substances in water.