Biology AHSGE Standard I- Appropriate Laboratory Materials

Appropriate Laboratory Materials CONTENT STANDARD I. Select appropriate laboratory glassware, balances, time measuring equipment, and optical instruments to conduct an experiment. ELIGIBLE CONTENT A. Select appropriate glassware for conducting experiments including a graduated cylinder, a beaker, a flask, a test tube, a microscope slide, a pipette, and a Petri dish. B. Select appropriate measuring equipment for conducting experiments including a balance and a stopwatch. C. Select appropriate optical instruments for conducting experiments including a compound microscope, an electron microscope, and a magnifying glass.

Measurement Universal system of measurement Systeme International (SI) or Metric System Based on units of ten King Hendry Died By Drinking Chocolate Milk Kilo- 1000s (k) Hecto- 100s (h) Deka- 10s (Da, Dk) Base Deci- 10ths (d) Centi- 100ths (c) Milli- 1000ths (m) Base units Volume, space- liters,cm 3 Mass/weight- Grams Distance, height, width, length- Meters

Measurement Accuracy refers to the agreement between a measurement and the true or correct value. Precision refers to the repeatability of measurement. Error refers to the disagreement between a measurement and the true or accepted value.

Glassware 1. Do not use glassware that is broken, chipped or cracked. 2. Always use tongs or a heat-resistant glove to heat glassware. a. Point test tube away from yourself and others when heating. b. Allow to cool before storing. 3. If a glassware breaks, do not touch with bare hands. Place in special broken glass container.

Glassware Graduated cylinder- piece of laboratory glassware used to accurately measure out volumes of chemicals for use in reactions. Generally more accurate and precise for this purpose than flasks. Read from bottom of meniscus Fluid displacement- Determine the volume of an irregular solid by placing in a graduated cylinder with a known amount of fluid and measuring the difference

Glassware Beaker- Simple container for liquids, very commonly used in laboratories. Generally cylindrical in shape, with a flat bottom Do not use to measure volume of a liquid. Use for holding and pouring liquids.

Glassware Fl ask- Wider vessel "body" and one (or sometimes more) narrower tubular sections at the top called necks which have an opening at the top. Flasks can be used for making solutions or for holding, containing, collecting, or sometimes volumetrically measuring chemicals, samples, solutions, etc. for chemical reactions Other processes such as mixing, heating, cooling, dissolving, precipitation, boiling (as in distillation), or analysis.

Glassware Pipette (also called a pipet, pipettor or chemical dropper )- Instrument used to transport a measured volume of liquid. Works by creating a vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid. May have a bulb for suction.

Glassware Petri dish- Shallow glass or plastic cylindrical dish that biologists use to culture cells, which can be bacteria, animal, plant, or fungus Agar is a gelatinous substance chiefly used as a culture medium for microbiological work

Glassware Test tube (culture tube )- Piece of laboratory glassware composed of a finger-like length of glass tubing, open at the top, with a rounded U- shaped bottom. Typically used by chemists to retain multiple discrete samples of materials, usually liquids, during chemical procedures and experiments Designed to allow easy heating of these samples.

Glassware Microscope slide- thin sheet of glass used to hold objects for examination under a microscope. Wet mount - Object to be viewed is prepared, or mounted, in water underneath a cover slip

Mass Measurement Balance (also balance scale, beam balance or laboratory balance) is used to measure the mass of an object. Triple-beam balance – Balance with a pan and three beams with sliding masses called riders At one end is a pointer Indicates whether the mass on the pan is equal to the mass on the beams

Mass Measurement Analytical balance- instrument used to measure mass to a very high degree of precision. The weighing pan(s) of a high accuracy (0.1 mg or better) Inside a see-through enclosure with doors so dust does not collect and so any air currents in the room do not affect the delicate balance.

Time Measurement Stop Watch- does what its name implies enables hand timing has millisecond accuracy and no artificial limit on hours

Distance Measurement Distance is the measurement from one point to another. How far away something is Can be length, width, height, depth, altitude, etc. Sometimes need to measure before the volume of a regular solid can be determined: V= L x W x H

Distance Measurement Ruler- the instrument used to rule lines and the calibrated instrument used for determining measurement

Distance Measurement A tape measure or measuring tape is a ribbon of cloth, plastic, or metal with linear-measure markings, often in both imperial and metric units. A meter stick measures up to 40 inches (3.281 feet) A yard stick measures up to 36 inches (3 feet)

Optical Instruments A microscope -instrument for viewing objects that are too small to be seen by the naked or unaided eye. optical instrument containing one or more lenses that produce an enlarged image of an object placed in the focal plane of the lens(es).

Optical Instrument Simple Microscope - Microscope with only one lens Compound Light microscope - Microscope with more than one lens which uses light to transmit image to your eye

Optical Instrument Electron microscope - uses electrons to illuminate and create an image of a specimen Can only view dry objects/dead specimens Can not view moving specimens Gives 3D visualization Transmission electron microscopy (TEM) involves a high voltage electron beam Scanning Electron Microscope (SEM) produces images by detecting low energy secondary electrons

Optical Instrument Magnifying glass - (Hand lens) a convex lens which is used to produce a magnified image of an object