BIO 101: Midterm Lab Practical (Labs 1 - 8)

observation

Information obtained through the senses.

inference

A conclusion reached on the basis of evidence and reasoning

hypothesis

a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

experiment

A research method in which an investigator manipulates one or more factors to observe the effect

qualitative data

descriptive data using words

quantitative data

numerical data

results

data and observations gathered from the experiment

conclusion

A summary based on evidence or facts

experimental/independent variable

part of the experiment that the scientist changes or manipulates

responding/dependent variable

the part of the experiment that is measured as data

constants (aka controlled variables)

factors that do not change in the experiment

control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

negative control

Control group where conditions produce a negative outcome

positive control

Group expected to have a positive result

repeated measures

Experiments in which a subject is exposed to more than one level of an experimental treatment.

length

distance between two points; measured in meters (m)

mass

the amount of matter in an object; measured in grams (g)

volume

The amount of space an object takes up; measured in liters (L)

temperature

A measure of how hot or cold something is; measured in Celcius (C) or Kelvin (K)

kilo

10^3

hecta

10^2

deca

10^1

deci

10^-1

centi

10^-2

milli

10^-3

meniscus

The curved upper surface of a liquid in a tube

beaker

dropper pipette

volumetric pipette

pipette pump

micropipette

Erlenmeyer flask

safety goggles

graduated cylinder

test tube

test tube rack

test tube holder

forceps

triple beam balance

thermometer

metric ruler

stage

platform which supports the specimen being viewed

arm

curve or slanted part which is held while carrying the microscope

ocular lens (eyepiece)

the lens that you look through

objective lenses

the lenses that are used to magnify the object

coarse adjustment knob

big knob moving the stage up and down

fine adjustment knob

small knob moving the stage up and down

base (foot)

the bottom of the microscope, used for support

slide

rectangular glass plate on which the specimen is mounted

total magnification

The power of a microscope, found by multiplying the power of the (eyepiece) by the power of the objective lens.

specimen

sample that is prepared to be viewed

Compound microscope

A microscope with two or more lenses.

field-of-view

When you look down a microscope, the circle that you see is called ''

400X

The total magnification of a 10X eyepiece lens coupled with the high power 40X objective lens

condenser

focuses light through the specimen

iris diaphragm

controls the amount of light passing through the specimen

nosepiece

Holds the objectives and can be rotated to change the magnification

light source

provides light

mechanical stage

holds the slide in position for viewing and has two adjustable knobs that control the precise movement of the slide

how to carry a microscope

one hand on the arm and one hand on the base

field of view

The area visible through the microscope eyepiece

how to clean and store a microscope

use a lens wipe (not a tissue/towel/sleeve etc); unplug it, rotate to the scanning objective lens, put the stage in its lowest position, cover it with a dust cover, place it in the cabinet

wet mount

a glass slide holding a specimen suspended in a drop of liquid (as water) for microscopic examination

pH scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14

pH

measure of hydrogen ion concentration

solution

A homogeneous mixture of two or more substances

acid

A substance that increases the hydrogen ion concentration of a solution; pH below 7

base

A substance that decreases the hydrogen ion concentration in a solution; pH above 7

neutral

hydrogen ion concentration equals hydroxide ion concentration; pH of 7

solute

A substance that is dissolved in a solution.

solvent

A liquid substance capable of dissolving other substances

buffer

weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH

antacid

a weak base that neutralizes stomach acid

litmus paper

an indicator paper that turns red in an acid and blue in a base

protein

a macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; it folds into a 3D shape that allows it to perform its function; most diverse macromolecule in terms of function

carbohydrates

a macromolecule that contains carbon, hydrogen, and oxygen; provides substrates for cellular respiration and therefore provides energy to the cell; also has some structural function;

lipids

a macromolecule that contains carbon, hydrogen, and oxygen; these are insoluble in water and are used for energy and building cell structures like the plasma membrane

nucleic acids

macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus; includes DNA, RNA, and ATP

nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

monomer

A simple compound whose molecules can join together to form polymers

polymer

A long molecule consisting of many similar or identical monomers linked together.

monosaccharides

Single sugar molecules like glucose and fructose

disaccharide

two monosaccharides linked together, like sucrose which is made of a glucose and a fructose

polysaccharide

multiple monosaccharides linked together, such as cellulose, starch, and glycogen

amino acid

Building blocks of protein

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

triglyceride

a lipid building block made of three fatty acid molecules and one glycerol molecule

dehydration synthesis (condensation) reaction

a chemical reaction in which two or more monomers combine resulting in the loss of a water molecule

hydrolysis reaction

A chemical reaction that breaks apart a larger polymer by adding a molecule of water

benedict's reagent

detects presence of reducing sugars (monosaccharides and disaccharides); postive results = green (low amount of sugar) and yellow/orange/red (higher amounts of sugar); negative results = blue

iodine test

detects the presence of starch (a polysaccharide); postive result = blue/black; negative result = yellowish brown

biuret test

detects the presence of proteins; positive result = violet; negative result = blue

emulsification test

detects the presence of lipids; positive result = droplets suspended in water; negative result = substance dissolves in water

emulsifer

molecules that contain a polar and non-polar end, like Tween, bile salts, and soaps

paper test

detects the presence of lipids; postive result = paper turns a different color; negative result = substance evaporates and paper stays the same color

cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

glycocalyx

The external surface of a plasma membrane that is important for cell-to-cell communication and identification

capsule

when the glycocalyx is bound more tightly to the cell and is denser and thicker