Midterm Exam Review for BSC1010L

Steps of the Scientific Method

Observations, Testable Questions, Formulate hypothesis (null hypothesis vs alternative hypothesis), Test hypothesis (Experiment-where measurements collected), Collect/Analyze Data, Make conclusions (reject or accept hypotheses)

Independent Variable

Controlled (we can control this variable, the cause)

Dependent Variable

Response (changes in function of the independent variable, the effect)

Calculations: Mean

Average of a number set (addition of all data and divide by 'n')

Calculations: Standard deviation

Calculate by subtracting the mean from the data set, square the deviation, and then add the sum

Metric system-conversions

K H D b d c m

Example of Independent Variable

Type of food being given to yeast

Example of Dependent Variable

The CO2 production

Length

measured in base unit 'm' meters (know how to use a measure with a ruler)

Volume

measured in base unit 'L' liters (know how to use and measure with a pipette, graduated cylinder (meniscus) and by water displacement)

Mass

measured in base unit 'g' grams (know how to use a triple beam balance and digital scale-taring)

Temperature

measured in 'C' Celsius (know how to read a thermometer)

pH

measure of the concentration of H+ ions (H+)

Acid

more H+ ions than OH- ions (i.e. the lower the pH, the more H+ ions present)

Base (alkaline)

more OH- ions than H+ ions

pH scale

scale from 1 to 14 with 1 being the most acidic and 7 being neutral

pH indicators

cabbage juice and pH alkacid test paper

Buffer

solution that resists change, made by mixing weak acid with its salt

Carbohydrates

monosaccharides, disaccharides, polysaccharides (starch)

Reagent: Benedict's

tests for presence of reducing sugars (blue is negative, green to reddish orange is positive) Includes hot plate for boiling water bath

Reagent: Iodine

tests for presence of polysaccharides-starch (bluish-black is positive, brown is negative) Drops of iodine in test tube

Proteins

made up of amino acids bound together by peptide bond

Reagent: Biuret

tests for presence of peptide bond in proteins (violet is positive). Adds drops of Biuret

Lipids

dissolve in non polar solvents but not in polar solvents such as water (insoluble in water)

Reagent: Sudan IV

tests for presence of lipids (red droplets/clumping is positive for lipids)

Grease spot test

test brown paper for presence of lipids (translucent is positive for lipids)

Compound Microscope

know the parts of the compound microscope and functions (ocular lens, objective lens, condenser, iris diaphragm, course and fine adjustment knob)

Ocular lens

lens that you look through, magnification 10x

Objective lens

magnify the image and improve resolution (4x, 10x, 40x, 100x)

Total Magnification (TM)

ocular lens x objective lens

Field of view

area that you can see through the ocular and objective lens

Dissecting Microscope

for specimen that are too large to view with a compound microscope (ex: external structures of organisms)

Eukaryotic cells

contain nuclei and membrane bound organelles

Plant cells

contain chloroplasts (chlorophyll) for photosynthesis, cell wall, central vacuole

Amyloplasts

for storing starch (dark round structures stained with iodine)

Diffusion

passive, directional movement of molecules from areas of high concentration to areas of low concentration

Osmosis

diffusion of water across permeable membrane (when molecules cannot cross membrane) to areas of high concentration of molecules

Hypotonic

lower concentration of solutes

Hypertonic

high concentration of solute

Isotonic

two solutions have equal concentrations of solutes

Water Potential

in animal cells, if water flows into the cell by osmosis, the cell can hemolyze (burst). While plant cells can swell without bursting due to their cell walls

Condenser

focuses light on specimen

iris diaphragm

Adjusts the amount of light that reaches the specimen.

fine adjustment knob

Moves the stage slightly to sharpen the image

course adjustment knob

Moves the stage up and down for focusing

null hypothesis

no significant difference between two groups

alternative hypothesis

proposes specific relationship between two groups