committee 2

Question 1

Whats the importance of crossing over of genes?

Answer 1

increase genetic variation

Question 2

what is the type of inheritance in AD diseases?

Answer 2

Vertical

Question 3

when looking at pedigrees,we sometimes see a skipped generation.why?

Answer 3

1) reduced penetrance
2) fresh mutation
3) expressed variability

Question 4

two ways AR diseases differ from AD diseases

Answer 4

no reduced penetrance and expressed variability

Question 5

what do you mean by neonatal?

Answer 5

once born till 1 month

Question 6

4 extra AD diseases to know

Answer 6

chronic glaucoma
hypertension
progeria'
huntingtons disease
 hereditory edema

Question 7

pattern of inheritance in AR diseases

Answer 7

horizontal

Question 8

what are factors increasing frequency of AR diseases

Answer 8

1)consanguinity
2)marriage in isolated pop or from same ethnic groups
cause these 2 help decrease gene pool

Question 9

what is azoospermia and in which disease do we see it?

Answer 9

absence of sperms in semen and its seen in cystic fibrosis

Question 10

4 extra AR diseases to know

Answer 10

1) galactosemia
2) sickle cell anemia
3) congenital deafness
4) tay sachs disease

Question 11

a benefit of males having Y instead of X

Answer 11

if they got the affecting X chromosomes they might show less syptoms

Question 12

when does lyonization occurs?

Answer 12

early development (1-2 weeks after conception)

Question 13

mechanism of lyonization,X inactivation

Answer 13

DNA methylation

Question 14

what gene controls x inactivation?

Answer 14

XIST gene on XiC (x inactivation center)

Question 15

2 types of lyonization

Answer 15

1) typical:irreversible and X chromosome chosen randomly

2) atypical:not randomly chosen,reversible,can be translocation or structural abnormality

Question 16

what is mosaicism?

Answer 16

having cells with different genotypes in same body

Question 17

Are there genes on X chromosome that escape inactivation?

Answer 17

pseudoautosomal genes ,,mainly found on p arm

Question 18

what is the biggest gene in our genome?

Answer 18

dystrophin

Question 19

what is the pattern in x linked dominant diseases?

Answer 19

vertical

Question 20

whats the name of genes on y chromosome?

Answer 20

holandric genes which are responsible for male characteristics

Question 21

what cells are rich in Mt?

Answer 21

muscles and neurons

thats why neuromuscular systems are more affected by mutations in mtDNA

Question 22

what do the 37 genes in mtDNA code for?

Answer 22

muscles and neurons

thats why neuromuscular systems are more affected by mutations in mtDNA

Question 23

3 types of mtDNA mutations

Answer 23

OXPHOS=oxidative phosphorilation

1- Missense mutations in genes of OXPHOS proteins*

2- Point mutations of tRNA and rRNA genes,*

3- Rearrangements causing deletions and
duplications in mtDNA molecules.*