The Scientific Method

Biology I Factoids

Factoid 315

• Section 1

• A graduated cylinder is used to measure volume accurately.

• The meniscus is the curve at the surface of the liquid.

• The meniscus is read from the center of the meniscus.

Factoid 316

• Other pieces of equipment used for measurement are the pipette, the burette, and the syringe.

Factoid 317

• Test tubes, beakers, and Erlenmeyer flasks are used for storing liquids – not for measuring.

Factoid 318

• The standard unit of mass is the gram. Mass is the measure of the amount of matter in an object. To measure mass, you typically use a triple beam balance.

Factoid 319

• The standard unit of length is the meter. Typically meter sticks are used to measure length.

Factoid 320

• The standard unit of temperature is degree Celsius. The temperature of something refers to how fast the molecules are moving.

Factoid 321

• The instrument used to see small objects is the compound light microscopes. These are the common microscopes found in the lab.

Factoid 322

• The electron microscope has greater resolution than a light microscope. You can not view living things using a light microscope.

Factoid 323

• Parts of the microscope include the arm, the base, the ocular lens, stage, stage clips, fine adjustment knobs, course adjustment knobs, light source, diaphragm, high power objective, low power objective, nosepiece, and body tube.

Factoid 324

• Total magnification is calculated by multiplying the object lens by the occular lens.

Factoid 325

• The field of view is what you can when looking through the eye piece.

• As you increase magnification, the field of view decreases.

Factoid 326

• The diaphragm controls the amount of light entering the microscope.

Factoid 327

• A Bunsen Burner uses gas to produce a flame.

• Test tubes should be pointed away from people when being heated.

• Do not heat a capped test tube.

• Hot plates do not use open flames but are used to heat liquids.

Factoid 328

• To pick up a heated test tube, you’d use a test tube clamp.

• To pick up a heated beaker, you’d use beaker tongs or heat/asbestos gloves.

• Treat all glassware as hot because hot glassware looks just like cold glassware.

Factoid 329

• Safety equipment includes the emergency eyewash station, safety shower, absorbent material to clean up spills, a biohazard container, broken glass container, fire extinguisher, goggles, gloves, and aprons.

Factoid 330

• Some of the common safety symbols include: biohazard, corrosive, flammable/combustible, no food or drink, poisonoous/toxic, and radiation.

Factoid 331

• Some common safety rules are

• Never pour chemicals down the drain.

• Never do unauthorized experiments.

• Tell your teacher about accidents.

• Don’t horse play.

• Clean up your area.

Factoid 332

• The Scientific Method• State the problem (Purpose)• Gather information (Research)• Form a hypothesis (Hypothesis)• Perform an experiment (Materials, Procedures)• Gather Data (Data)• Form a Conclusion (Conclusion)• Remember how to write a lab report.

Factoid 333

• The control group is the group of the experiment that is kept under normal conditions.

• The experimental group is the group where a variable has been changed.

Factoid 334

• A placebo is an inert substance given to the control group and should have no effect on the control group.

Factoid 335

• A constant (or control) refers to a variable that is kept the same in the control group and the experimental group.

Factoid 336

• The independent variable is plotted on the X axis and refers to the variable the experimenter can control and manipulate.

Factoid 337

• The dependent variable is plotted on the Y axis and refers to the variable that changes in response to a change in the independent variable. It DEPENDS on the independent variable.

Factoid 338

• A line graph is used to plot continuous data like time.

Factoid 339

• A bar graph is used for non-continuous data such as flower color.

Factoid 340

• A pie graph is used for data expressed in percentages.