mandeline genetics

Question 1

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

Answer 1

• gene recognised by transcription factors
• rna polymerase

Question 2

true or false:
pedigree analysis include -
- autosomal dominant
- autosomal recessive
- y linked
- x linked recessive
- x linked dominant

Answer 2

true

Question 3

most autosomal dominant inheritance is expressed in —- and they die before —- v late onset disease

Answer 3

• heterogeneous
• maturity

Question 4

—– in autosmal dominant at selective disadvantage and they die before —–

Answer 4

• homogenous
• reproductive maturity

Question 5

AD allele frequencies are usually —

Answer 5

low

Question 6

• familial gyoercholestrole
• polycystic kidney disease
  -neurofibromatosis
• familial adenomatous polyposis (FAP )
  are all examples of —-

Answer 6

AD

Question 7

most common AD mating is :

Answer 7

affected and normal parents

Question 8

apparent exceptions to the AD pattern :
—– refers to sporadic cause may arise within families by de-nevo mutation

Answer 8

mutation

Question 9

apparent exceptions to the AD pattern :
—– refers to the nature and severity of the phenotype but everyone w the genotype show it

Answer 9

variable expressivity

Question 10

apparent exceptions to the AD pattern :
—- refers to the proportion of individuals with a given genotype who show the associated phenotype

Answer 10

reduced penetrance

Question 11

mutation types are:
1- deletion or insertion which leads to —–
2- single base subsitutions as:

Answer 11

• frameshift mutation which leads to disruption in code
• polymorphism , missense , nonsense , mutation position ?

Question 12

—- refers to the synonyous mutation as: CCA or CCC both code for proline

Answer 12

polymorphism

Question 13

—- non-synonymous by which one amino acid is replaced by another as : UUC —> UUA

Answer 13

missesne mutation

Question 14

—- an amino acid codon becomes a stop codon

Answer 14

nonsense mutation

Question 15

—- creates or destroy an exon-intern splicing signal which can be done by all of the above mentioned mutations

Answer 15

splice-site

Question 16

—- coding region of a gene = functional significance promoter/regualtory elements which alters expression

Answer 16

mutation position

Question 17

to name the mutation:
example:
R408W refers to

Answer 17

R: codon
408: position
W: what it replaces

Question 18

how does mutation at a single gene cause a disease phenotype?

Answer 18

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

Question 19

yes or no :
in heterogeneous , is the product from the one normal allele sufficient to carry our the function of the gene

Answer 19

no in AD

Question 20

in autosomal recessive storms are seen only in —–

Answer 20

homogenous recessive ( 2 mutant alleles no normal ones )

Question 21

true or false:
in AR inheritance the carriers are selective disadvatahe even if the affected indivuials don’t breed the mutation can be widespread

Answer 21

false , not in a selective disadvantage

Question 22

AR diseases are —- common that AD

Answer 22

more

Question 23

the most common type of mating in AR is:

Answer 23

• 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

Question 24

identifying AR diseases
( read through them not important much )

Answer 24

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

Question 25

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:

Answer 25

• 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

Question 26

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

Answer 26

true

Question 27

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

Answer 27

true as:
1- cystic fibrosis
- phenylketrunria
3- sickle cell anaemia
4- a,b thalassemia

Question 28

—– 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

Answer 28

• genetic drift
• genetic migartion
• selection