Unit 8 Vocab

Mutation

A change in the genetic code.

Somatic Cells

Body cells.

Germ Cells

Gametes such as sperm and egg.

Neutral mutation

Mutations that have little or no effect on gene function.

Harmful mutation

Mutations that produce defective proteins.

Lethal mutation

Change proteins that are so vital to life that they cause death, usually before birth.

Beneficial mutation

Mutations that help an organism survive and reproduce.

Autosomal Recessive

A mutation on chromosomes 1-22 that causes a protein to be NON-FUNCTIONAL and would appear recessive to the normal working allele.

Carrier

A heterozygous person who carries a recessive allele for a genetic disorder, but doesn’t show the disorder themselves.

Autosomal Dominant

A mutation on chromosomes 1-22 that codes for a new protein whose action masks the normal allele.

Karyotype

A picture of an organism’s chromosomes.

Sex chromosomes

Chromosomes that determine the sex of an organism.

Autosomes

All chromosomes besides the X and Y.

Pedigree

Diagram that shows how genes are passed on in families over several generations.

Sex linked trait

Traits that show up in different percentages in males and females because they move with the sex chromosome.

Y-linked gene

Genes carried on the Y chromosome.

X-linked gene

Genes carried on the X chromosome.

Nondisjunction

Homologous chromosomes fail to separate during MEIOSIS.

Sex Linked Recessive

Mutations linked to the X or Y chromosomes that appear recessive to the normal allele.

Sex Linked Dominant

Mutations linked to the X or Y chromosomes that appear Dominant to the normal allele.

Barr Body

Turned off X chromosome that condenses and forms a dense region in the nucleus.