Bio 1 Lab Midterm

Scientific Method Steps

Observation → Question → Hypothesis → Experiment → Data → Conclusion

Observation

Noticing something using senses

Testable Question

A question that can be measured or answered with data

Hypothesis

A prediction that can be tested

Null Hypothesis (H0)

States no effect or no difference

Alternative Hypothesis (H1)

States there is an effect or difference

Independent Variable (IV)

Variable you change (manipulated)

Dependent Variable (DV)

Variable you measure (response)

Replication

Repeating experiment trials to improve reliability

Control

A standard for comparison in an experiment

Mean

Average (sum ÷ number of values)

Standard Deviation

Measure of how spread out data is

Accuracy

How close to the true value

Precision

How close measurements are to each other

Metric Order

Kilo Hecto Deka Base Deci Centi Milli

Meters in 25 cm

0.25 m

Length Unit

Meter (m)

Volume Unit

Liter (L)

Mass Unit

Gram (g)

Temperature Unit

Celsius (°C)

Meniscus

Curve of liquid when measuring volume

Taring

Resetting scale to zero before measuring

Molarity Formula

M = moles / liters

Dilution Formula

ViMi = VfMf

pH

Measure of H+ ion concentration

Acid

More H+ ions, low pH

Base (Alkaline)

More OH- ions, high pH

Neutral pH

7

Buffer

Solution that resists pH change

Carbohydrates

Sugars and starches

Lipids

Fats, insoluble in water

Proteins

Made of amino acids

Nucleic Acids

DNA and RNA

Benedict’s Test (Sugars)

Green to red = positive

Iodine Test (Starch)

Blue-black = positive

Biuret Test (Protein)

Violet = positive

Sudan IV Test (Lipids)

Red droplets = positive

Grease Spot Test

Translucent = positive for lipids

Dische Test (DNA)

Blue = positive

Positive Control

Known to give positive result

Negative Control

Known to give negative result (water)

Ocular Lens

10x magnification lens you look through

Objective Lenses

4x, 10x, 40x, 100x lenses

Total Magnification

Ocular × Objective

Example TM (10x × 40x)

400x

Condenser

Focuses light on specimen

Iris Diaphragm

Controls light amount

Coarse Adjustment

Rough focusing

Fine Adjustment

Sharp focusing

Prokaryotic Cells

No nucleus

Eukaryotic Cells

Have nucleus

Plant Cell Features

Cell wall, chloroplast, vacuole

Chloroplast

Photosynthesis organelle

Amyloplast

Stores starch

Nucleus

Contains DNA

Diffusion

Movement from high to low concentration

Osmosis

Diffusion of water

Hypotonic Solution

Lower solute concentration

Hypertonic Solution

Higher solute concentration

Isotonic Solution

Equal solute concentration

Hemolysis

Animal cell bursts in hypotonic solution

Plasmolysis

Plant cell shrinks in hypertonic solution

Iodine Result in Starch

Blue-black color

Phenolphthalein in Base

Turns red