Mutations and Genetic Recombination Section 18.3

Mutation

A permanent change in a cell’s DNA

Includes changes in nucleotide sequence, alteration of gene position, gene loss, or duplication and insertation of foreign sequences

An inheritable mutation has the potenetial to affect an entire gene pool

Somatic Cell Mutation

Permanent change in the genetic material of a body cell, not including germ cells, during the lifetime of an organism

Is copied during DNA replication and passed on to daughter cells, but passed on to future generations

Germ Line Mutation

Permanent change in the genetic material of a reproductive cell during the lifetime of an organism that is passed on to future generations

Point Mutation

Permanent change in the genetic material of a cell that affects one or just a few nucleotides

May involve the substituation of one nucleotide for another, or the insertion or deletion of one or more nucleotides

Silent Mutation

Permanent change in the genetic material of a cell that has no effect on the function of the cell

Mis-Sense Mutation

Permanent change in the genetic material of a cell that results in a slightly altered but still functional protein

Nonsense Mutation

Permanent change in the genetic material of a cell that renders a gene unable to code for a functional protein

Frameshift Mutation

Permanent change in the genetic material of a cell caused by the insertion or deletion of one or two nucleotides so that the entire reading frame of the gene is altered

Usually results in a nonsense mutation

Mutagen

Substance or event that increases the rate of mutation in an organism

May be physical or chemical

Physical Mutagen

Agent that can forcibly break a nucleotide sequence, causing random changes in one or both strands of a DNA molecule

e.g. X rays

Chemical Mutagen

Molecule that can enter the cell nucleus and induce a permanent change in the genetic material of the cell by reacting chemically with DNA

e.g. nitrites

Carcinogenic

Cancer-causing

Describes a factor, such as a chemical mutagen, that is associated with one or more forms of cancer

Mitochondrial DNA (mtDNA)

DNA within the mitochondria

Is genetically indentical to that of the female parent because the cytoplasm of offspring is derived from the egg (ovum)

Genetic Engineering

manipulation of genetic material to alter genes and blend plant, animal, and bacterial DNA

Recombinant DNA

A molecule of DNA that includes genetic material from different sources

Restriction Enzyme

Enzyme in prokaryotes that catalyzes the cleavage of DNA at specific nucleotide sequences

Restriction Endonuclease

Type of restriction enzyme that recognizes a specific short sequence of nucleotides within, rath thn ath the ends of, a strand of DNA and cuts the strand at that particular point within the sequence

Restriction Fragment

Small segments of DNA cut from a DNA molecule by a restriction endonuclease

Gel Electrophoresis

Tool used to separate molecules according to their mass and charge

Can be used to separate fragments of DNA

DNA Fingerprint

The pattern of bands into which DNA fragments sort during gel electrophoresis