Scientific explanations are built by combining evidence that can be observed with what people already know about the world.
Learning about the historical development of scientific concepts or about individuals who have contributed to scientific knowledge provides a better understanding of scientific inquiry and the relationship between science and society.
Science provides knowledge, but values are also essential to making effective and ethical decisions about the application of scientific knowledge.
Scientific explanations are accepted when they are consistent with experimental and observational evidence and when they lead to accurate predictions.
All scientific explanations are tentative and subject to change or improvement. Each new bit of evidence can create more questions than it answers. This leads to increasingly better understanding of how things work in the living world.
Interpretation of data leads to development of additional hypotheses, the formulation of generalizations, or explanations of natural phenomena.
Genes are inherited, but their expression can be modified by interactions with the environment.
Every organism requires a set of coded instructions for specifying its traits. For offspring to resemble their parents, there must be a reliable way to transfer information from one generation to the next. Heredity is the passage of these instructions from one generation to another.
Hereditary information is contained in genes, located in the chromosomes of each cell. An inherited trait of an individual can be determined by one or by many genes, and a single gene can influence more than one trait. A human cell contains many thousands of different genes in its nucleus.
In asexually reproducing organisms, all the genes come from a single parent. Asexually produced offspring are normally genetically identical to the parent.
In all organisms, the coded instructions for specifying the characteristics of the organism are carried in DNA, a large molecule formed from subunits arranged in a sequence with bases of four kinds (represented by A, G, C, and T). The chemical and structural properties of DNA are the basis for how the genetic information that underlies heredity is both encoded in genes (as a string of molecular "bases") and replicated by means of a template.
Cells store and use coded information. The genetic information stored in DNA is used to direct the synthesis of the thousands of proteins that each cell requires.
Genes are segments of DNA molecules. Any alteration of the DNA sequence is a mutation. Usually, an altered gene will be passed on to every cell that develops from it.
The many body cells in an individual can be very different from one another, even though they are all descended from a single cell and thus have essentially identical genetic instructions. This is because different parts of these instructions are used in different types of cells, and are influenced by the cellÕs environment and past history.
For thousands of years new varieties of cultivated plants and domestic animals have resulted from selective breeding for particular traits.
In recent years new varieties of farm plants and animals have been engineered by manipulating their genetic instructions to produce new characteristics.
Different enzymes can be used to cut, copy, and move segments of DNA. Characteristics produced by the segments of DNA may be expressed when these segments are inserted into new organisms, such as bacteria.
Inserting, deleting, or substituting DNA segments can alter genes. An altered gene may be passed on to every cell that develops from it.
Knowledge of genetics is making possible new fields of health care; for example, finding genes which may have mutations that can cause disease will aid in the development of preventive measures to fight disease. Substances, such as hormones and enzymes, from genetically engineered organisms may reduce the cost and side effects of replacing missing body chemicals.
Follows safety rules in the laboratory
Uses metric ruler to measure length
Uses chromatography and/or electrophoresis to separate molecules
Organizes data through the use of data tables and graphs
Analyzes results from observations/expressed data
Formulates an appropriate conclusion or generalization from the results of an experiment
Recognizes assumptions and limitations of the experiment