Unit 2: Scanning Electron Microscopes
Kingdoms
groups organisms of all life into six major categories
Experimental Group
identical to the control group except for one factor, the independent variable
eyepiece(ocular lense)
magnifies the image, usually 10 times
Domain
major subdivions of all organisms
Objective Lens
Light passes through the specimen adn thn through the objective lens which is located directly above the specimen
Metric Systema
a decimal-based standard of measurement that is used by scientists
Light Source
a light bulb that provides light for viewing the image
Scanning Electron Microscope
a microscope that produces an enlarged, three dimensional image of an object by using a beam of electrons rather than light
Compoudn Light Microscope
a microscope that shines light through a specimen and has two lenses to magnify an image
Transmission Electron Microscope
a microscope that transmits a beam of electrons through a very thin slice of specimen and that can magnify up to 200,000 times
Stage
a platform that supports a slide holding the specimen
hypothesis
a proposed explanation for the way a particular aspect of the natural world functions
Gene
a short segementof DNA that contains the instructions for a single trait of an organism
Prediction
a statement that forecasts what would happen in a test situation if the hypothesis were true
Natural Selection
theory that says organismsthat have certain favorable traits are better able to survive and reproduce successfully than organisms that lack these traits
Adaptations
traits that improve an individuals ability to sruvive and reproduce
Experiment
used to test a hypothesis and its predictions
Reproduction
all organisms profuse new organisms like themselves
Theory
an explanation for some phenomenon that is based on observation, experimentation, and reasoning
Ecosystems
are communities of living species and their physical environments
Tissues
are groups of cells that have similar abilities and that allow the organ to function
Organelles
are tiny structures that carry out untions necessary for the cell to stay alive
Biological molecules
chemical compounds that provide physical structure and that bring about movement, energy use, and other cellular functions
Evolution
descent with modification
Dependent Variable
is affected by the independent variable, the factor that changes as a result of manipulation of one or more factors
Organization
is the high degree of order within an organisms internal and external parts aand in its interactions with the living world
Base Units
one of the fundemental units of measurement that describes length, mass, time and other quiantites and from which other unis are derived
multicellular
organisms made up of multiple cells
Unicellular
organisms made up of one cell
Scientific Method
organized approach characterizing science
Development
process by which an organism becomes a mature adult
Control Group
provides a normal standard against which the biologist can compare results of the experimental group
Organs
structures that carry out specialized jobs within an organ system
Biology
study of life
Observation
the act of percieivng a natural occurance that causessomeone to pose a question
Ecology
the branch of biology that studies organisms interacting with each other and with the environment
Division
the formation of two new cells from an existing cell
Magnification
the increase of an objects apparent size
Homeostasis
the maintenance of a stabel level of internal conditions even though the environmental conditions are constantly changing
Resolution
the power to show details clearly in an image
Peer Review
the process in which experts in a given field examine the results and conclusions of a scientist's study before that study is accepted for publication
Cell
the smallest unit that can perform all life's processes
nosepiece
the structure that holds the set of objective lens
Metabolism
the sum of all the chemical reactions that take in and tranform energy and materials from the environment
Independent Variable
the variable that the experimenter manipulates