mutations Flashcards
mutation
changes in genetic material
what types of mutations can be passed to offspring?
mutations in gametes
mutations in body cells will be passed onto other body cells through mitosis
what are the 2 types of mutations?
chromosomal alterations and gene mutations
chromosomal mutations
- nondisjunction
- down’s syndrome
- polyploidy
nondisujnction
when homologous chromosomes do not separate
down’s syndrome
presence of an extra 21st chromosome nondisjunction
polyploidy
containing an extra whole set of chromosomes (4n/3n)
gene mutations
any alteration of the DNA sequence
types: substitution (insertion), deletion, addition, inversion, translocation
mutagenic agents
caused y X-rays, UV rays, radioactive substances, asbestos fibers and formaldehyde
human chromosomal disorders
cystic fibrosis, down’s syndrome, tay-sachs disease, color blindness
cystic fibrosis
recessive allele from a substitution. excess mucus in lungs
tay-sachs disease
recessive genetic disorder (by substitution) that causes deterioration of the nervous system. unable to make an enzyme that breaks down fats
color blindness
x-linked recessive allele women are carriers; men get it
sickle cell anemia
recessive allele caused by substitution–sickle shaped cells–>can get stuck in veins b/c of shape
phenylketonuria (PKU)
recessive allele by substitution. not able to make an enzyme needed to metabolize (phenylalanine)–> mental retardation **could go on a diet
amniocentesis
sample of amniotic fluid is removed from the fetus
**for tay-sachs and down’s syndrome
screening tests
urine tests **for sickle cell anemia and tay-sachs
karyotyping
pic of chromosome **for abnormalities in chromosome structure and #
translocation
2 non-homologous pairs’ chromosome parts are switched
inversion
chromosome segment breaks off and flips around backwards then reattaches
