Tools of the Biologist

In the Lab…Safety First! Be Prepared Read the lab before you begin

Know the equipment

Wear proper clothing No open toe shoes. Wear lab aprons when working with chemicals.

Be Cautious with Chemicals Know the chemical you are using and how it should be handled. If a chemical comes in contact with your skin, wash with soap immediately. Let your teacher know!

Use safety goggles when working with chemicals, heat or glass. Know where the safety equipment is.

Lab Don’ts! Do Not: eat or drink in the lab taste any chemicals or substances you are working with use your mouth for pipetting substances handle broken glass with bare hands pour chemicals down the drain without permission operate lab equipment without permission perform your own experiments unless given permission leave any heated materials unattended place flammable substances near heat engage in childish antics such as horseplay or pranks

Lab Equipment & Measurement

SI Units of Measure SI or International System of Units Meters measure length Liters measure volume of a liquid Cubic meters measure volume of a solid Grams measure mass Degrees Celsius measure temperature

Everything is multiples of 10!

Less than one… Micro- (µ ): one millionth (0.000001) Milli- (m): one thousandth (0.001) Centi- (c): one one-hundredth (0.01) Deci- (d): one-tenth (0.1)

More than One… Deka (da): ten (10) Hecto (h): one hundred (100) Kilo (k): one thousand (1000) Mega (M): one million (1,000,000)

To convert units kilo hecto deka one deci centi Milli gram, meter or liter To change one unit to another, move the decimal point the number of places and the direction of the unit you are changing to. Example: 400 kilograms = ______________ grams? Start with 400. Move the decimal point three places to the right. 400 kilograms = 400,000grams.

To measure length Metric ruler

To measure volume of a liquid Meniscus Graduated Cylinder Beaker Oops! Wrong one… That’s the one

To measure mass Electronic balance Triple beam balance

From space to an oak tree, in metric units

Metric Measurement Why Science Uses Metric

Microscopes Magnify images Compound light microscope Dissecting microscope Electron microscope

Compound light microscope Uses multiple lenses to magnify image Lenses in eyepiece and objectives Determine total magnification by multiplying eyepiece times objective magnification

Dissecting microscope Magnification of three-dimensional objects Does not magnify to the extent of a compound microscope

Wolf spider, taken with a dissecting microscope

Wolf spider fang, taken with compound microscope

Electron Microscope Uses a particle beam of electrons to magnify up to 2 million times Ant magnified with scanning electron microscope

Measuring with a Microscope

What is the diameter of the field of view? Under 40X magnification, place a ruler on the stage and measure the diameter of the field of view

Each line of the ruler represents one millimeter (mm) or 1000 µ. The diameter of this field of view is 4 mm or 4,000 µ

Remove the ruler and place a slide on the stage. Estimate the number of cells that can fit across the widest point of the field. If the diameter of the field of view is 4 mm and 2 cells can fit across, then the diameter of one cell is 2 mm or 2000 µ (1 mm = 1000 µ) 4 mm 2 cells fit

INDICATORS Chemicals that change color to show the completion of or to test for a particular reaction Common indicators: Starch indicator ( Iodine)- turns blue-black in the presence of starch Methyl blue- stains cell parts so you can see them pH paper- indicates whether a substance is an acid, a base or neutral

pH SCALE pH scale http://pubs.usgs.gov/gip/acidrain/gifs/fig02.gif

Ordering Life Classification

Why do we classify things? For easier study There are millions of organisms on the earth; approximately 1.5 million have been already named) Organisms are classified by their: physical structure (how they look) evolutionary relationships embryonic similarities (embryos) genetic similarities (DNA) biochemical similarities

Broad to Specific

Broad to Specific

Broad to Specific

Broad to Specific

Broad to Specific

Broad to Specific

Broad to Specific

The 5 Kingdoms http://image.wistatutor.com/content/feed/tvcs/FiveKingdoms20Animals2.jpg

Nomenclature a system for naming things In biology there is a two-word system that is used to name organisms. BINOMIAL NOMENCLATURE (a two named--naming system). GENUS & SPECIES Ex: Humans are known as Homo sapiens

Dichotomous Keys Used to identify organisms A series of either/or statements Dichotomous means “divided into two parts”

Citations http://image.wistatutor.com/content/feed/tvcs/FiveKingdoms20Animals2.jpg http://pubs.usgs.gov/gip/acidrain/gifs/fig02.gif