Genetics test 2 Flashcards
Mutation
a change in DNA (genetic material)
Mutagen
agent that raises rate of mutation above spontaneous rate
Point Mutation
substitution of one base pair for another
Frameshift mutation
insertion or deletion of a base pair
Hereditary
transmissible from cell to cell
Congenital
present at birth
Phenocopy
condition resulting from environmental factors that mimics a genetic condition
Carcinogen
physical or chemical agent that causes cancer
Teratogen
physical or chemical agent that causes birth defects
Plolyploidy
extra sets of chromosomes
Aneuploidy
an extra or missing chromosome, trisomy
Down syndrome
3 copies of chromosome 21, trisomy 21
Cri-du-chat
missing part of short arm of chromosome 5
William Syndrome
Deletion of 26 genes on chromosome 7
Reciprocal Translocation
2 nonhomologous chromosomes exchange part of their arms
Familial Down Syndrome
Robertsonian Translocation between chromosome 21 and 14
Gene
Segment of DNA
Allele
Form of a gene
Locus
position of gene on chromosome
Law of independent Assortment
The migration of alleles of one gene into the gametes does not influence the migration of alleles at a second gene
Law of Random Segregation
Heterozygous individuals produce two gamete types frequently
Penetrance
the per cent individuals which show the phenotype that is expected for a particular genotype
Expressivity
the variation in severity for a particular genetic trait
Pleiotropic effects
one gene has an effect on several aspects of an individuals phenotype
Epistasis
One trait is controlled by 2 or more genes such that the gene products interact to determine the phenotype for 1 trait
Osteogenesis imperfecta
Dominant gene affects production of collagen in bones, short stature and weak muscles
Nail-Patella Syndrome
Abnormal development of fingers and toenails, dominant allele
Marfans Syndrome
long fingers and toes, heart valve problems, dominant allele
Primary Sex ratio
ratio of male:female at conception
Secondary sex ratio
ratio of male:female at birth
Tertiary sex ratio
ratio of male:female any time after birth
Hemizygous
individual only has 1 copy of the genetic locus
Homozygous
both alleles for the gene are the same
Heterozygous
the two alleles for the gene differ
Holandric
transmission of gene on Y chromosome
Duchenee Muschualr Dystophy
Defective dysrophin protein, muscle degeneration, paralysis and death, holandric
Hemophilia
Recessive, X-lnked, clotting factor
Ovotestestes
both ovaries and testes
SRY Gene
Sex determining region of the Y, codes for testis determining factor which triggers undifferentiated gonadal tissues to form testis
Androgen Insensitivity
xy individual that looks like a female
Guevedoces
Penis at age 12, ambiguous sex at birth
Congenital Adrenal Hyperplasia
Missing enzyme causes overproduction of male formones
Turner Syndorme
One x chromosome, no other chromosome
Klinefelter Syndrome
XXY
Barr body
Inactivated x
Fragile X Syndrome
extra copies of trinucleotide CGG on x chromosome
Rett Syndrome
X linked dominant, mutant MECP2 gene that regulates other genes, autistic type symptomes
Amelogenesis imperfecta
abnormal tooth enamel, x linked dominant
Cogenital Generalized Hypertrichosis
werewolf syndrome, x linked dominant
Congenital Effect
disease present at birth
Radiation measured in?
Sieverts, average person recieves 6.2 mSv a year
Ames test
mixes a chemical, liver extract and bacteria to determine if the chemical causes mutations
Williams Syndrome
Due to a deletion
