Benchmark 5B
The Living Environment: Heredity
Grades 9-12, page 109
Genes are segments of DNA molecules. Inserting, deleting, or substituting
DNA segments can alter genes. An altered gene may be passed on to every
cell that develops from it. The resulting features may help, harm, or have
little or no effect on the offspring's success in its environment.
NSES Content Standard C
Life Science: Reproduction and heredity
Grades 5-8, page 157
Hereditary information is contained in genes, located in the chromosomes
of each cell. Each gene carries a single unit of information. An inherited
trait of an individual can be determined by one or many genes, and a single
gene can influence more than one trait. A human cell contains many thousands
of different genes.
NSES Content Standard C
Life Science: The molecular basis of heredity
Grades 9-12, page 185
In all organisms, the instructions for specifying the characteristics
of the organism are carried in DNA, a large polymer formed from subunits
of four kinds (A,G,C, and T). The chemical and structural properties of
DNA explain how the genetic information that underlies heredity is both
encoded in genes (as a string of molecular "letters") and replicated (by
a templating mechanism). Each DNA molecule in a cell forms a single chromosome.
NSES Content Standard C
Life Science: The molecular basis of heredity
Grades 9-12, page 185
Changes in DNA (mutations) occur spontaneously at low rates. Some of
these changes make no difference to the organism, whereas others can change
cells and organisms. Only mutations in germ cells can create the variation
that changes an organism's offspring.
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