mandeline genetics Flashcards
certain regions on dna consists of sequence that recognise the info for making info —– , —— transcribed the info into mrna molecule for translation into a protein at the ribosomes
- gene recognised by transcription factors
- rna polymerase
true or false:
pedigree analysis include -
- autosomal dominant
- autosomal recessive
- y linked
- x linked recessive
- x linked dominant
true
most autosomal dominant inheritance is expressed in —- and they die before —- v late onset disease
- heterogeneous
- maturity
—– in autosmal dominant at selective disadvantage and they die before —–
- homogenous
- reproductive maturity
AD allele frequencies are usually —
low
- familial gyoercholestrole
- polycystic kidney disease
-neurofibromatosis - familial adenomatous polyposis (FAP )
are all examples of —-
AD
most common AD mating is :
affected and normal parents
apparent exceptions to the AD pattern :
—– refers to sporadic cause may arise within families by de-nevo mutation
mutation
apparent exceptions to the AD pattern :
—– refers to the nature and severity of the phenotype but everyone w the genotype show it
variable expressivity
apparent exceptions to the AD pattern :
—- refers to the proportion of individuals with a given genotype who show the associated phenotype
reduced penetrance
mutation types are:
1- deletion or insertion which leads to —–
2- single base subsitutions as:
- frameshift mutation which leads to disruption in code
- polymorphism , missense , nonsense , mutation position ?
—- refers to the synonyous mutation as: CCA or CCC both code for proline
polymorphism
—- non-synonymous by which one amino acid is replaced by another as : UUC —> UUA
missesne mutation
—- an amino acid codon becomes a stop codon
nonsense mutation
—- creates or destroy an exon-intern splicing signal which can be done by all of the above mentioned mutations
splice-site
—- coding region of a gene = functional significance promoter/regualtory elements which alters expression
mutation position
to name the mutation:
example:
R408W refers to
R: codon
408: position
W: what it replaces
how does mutation at a single gene cause a disease phenotype?
1- haplosuffiency: where normal physiological requires more than 50% of the gene product as structural protein, Ts , receptors and enzymes , no margin safety loss of 50% of normal activity of protein = disease
2- dominant -ve effect: abnormal protein produced interferes w the function of the product of a normal allele
3- gain function: function of mutant protein is enhanced aa: achondroplasia and huntigtons disease
4- loss of hentrogenity: dominantly inherited cancers , inherited copy of mutant gene and random loss of normal allele , even in only few cells render those cells cancerous
yes or no :
in heterogeneous , is the product from the one normal allele sufficient to carry our the function of the gene
no in AD
in autosomal recessive storms are seen only in —–
homogenous recessive ( 2 mutant alleles no normal ones )
true or false:
in AR inheritance the carriers are selective disadvatahe even if the affected indivuials don’t breed the mutation can be widespread
false , not in a selective disadvantage
AR diseases are —- common that AD
more
the most common type of mating in AR is:
- unaffected carrier father and unaffected carrier mother by which the 2 carriers mate and produce :
1 in 2 carrier
1 in 4 unaffected child
1 in 4 normal child
identifying AR diseases
( read through them not important much )
1- newborn screening programmes
2- mutable affected siblings within large sib ships
3- parental consanguinity
4- demonstration of partial defect in obligate hetrogenous as structural qauantitve
1- monogenic disease refers to a — defect in the gene where the same clinically diagnosed diseases are caused by different dna seqeqeunce defect producing similar or identical phenotype
2-allelic hetrogenity refers to the diff dna sequence/mutation on the — gene example:
3- locus heterogeneity refers to the dna sequence/mutation on — genes example:
- single
- same gene , phenylketonuria PKU due to mutation of the phenylanline hydroxyls PAH where it convert The to Try and its AR
- diff gene , complex pathway or complex structure in ear or eye as: retinis prigemtosa ,retinal dystrophy as abornmalities in the photoreceptors rods and cones or the retinal pigment epithelium RPE which leads to visual loss . symptoms include: night blindness , tunnel vision , blindness
true or false:
-the predicted residual activity PRA is known about mutant PAH protein
-different mutations lead to different phenotype
- genetic difference within and between population is part of the evolutionary bio
true
true or false:
the effect of ethnic variation in allele frequency , these affect the risk of calculations due to higher carrier frequency which is an example of AR inheritance
true as:
1- cystic fibrosis
- phenylketrunria
3- sickle cell anaemia
4- a,b thalassemia
—– refers to the change in frequency of an existing gene variant in population due to a random chance
—– refers to the introduction of genetic variant from one population to another which changes the composition of the gene pool of the receiving population
—– the change in the frequency under advantage
- genetic drift
- genetic migartion
- selection
