L.2

Question 1

What is the chromatin structure?

Answer 1

Chromatin ——>nucleosome —-> 1) histone amplification 2) DNA methylation

Question 2

Explain Euchromatin ?

Answer 2

Active , unmethylated cytosines and acetylated histones

Question 3

Explain Heterochromatine ?

Answer 3

Condensed , methylated cytosine and deacetylated histones

Question 4

Conventional cytogenetics can detect chromosomal changes size what ?

Answer 4

Less than 5 Mb

Question 5

What are the two categories of chromosomal structural abnormalities?

Answer 5

Balanced and unbalanced

Question 6

How can u differentiate between balanced and unbalanced chromosomal changes?

Answer 6

Balanced will not gain or loss genetic content
Unbalanced will gain and loss // // //

Question 7

Structural chromosomal abnormalities is inheritable if it’s where ?

Answer 7

Germ line

Question 8

What are the two types of deletion ?

Answer 8

Large deletion ( > 5Mb)
Small deletion ( < 2Mb )

Question 9

Give examples for large and small deletion ?

Answer 9

Large : cri-du-chat syndrome del of chr 5
Small : smith-magennis syndrome del of chr 17p11.2

Question 10

What are the types of chromosomal structural abnormalities?

Answer 10

Deletion
Duplication
Inversion
Translocation

Question 11

What happen in inversion ?

Answer 11

Two breaks occur at the chromosome and then this part of the Chr rotate in 180 degree before re-joining

Question 12

Example of inversion

Answer 12

Haemophilia A gene 8 Chr 22

Question 13

What are the two types of translocation

Answer 13

Reciprocal translocation
Robertsonian translocation

Question 14

What is reciprocal translocation

Answer 14

When two chr swap non-homologous sections

Question 15

Does the n of chr and the genetic content chain in Reciprocal translocation

Answer 15

No stay the same so it’s balanced

Question 16

What happen in robertsonian translocation?

Answer 16

Break occurs at the short arm of acrocentric chromosome which result in fusion of chromosome

Question 17

Why does change in the robertsonian translocation

Answer 17

Chr number is less but the genetic content stay the same so it’s balanced

Question 18

Dawn syndrome which type of chromosomal abnormalities

Answer 18

Robertsonian translocation

Question 19

Which chromosome involved in Dawn syndrome

Answer 19

rob ( 14 ; 21) (21 ; 21 ) ( 21+)

Question 20

What happen in the balanced structural abnormalities of chromosome

Answer 20

DNA packaged is incorrect and phenotype is normal

Question 21

CML which chromosome

Answer 21

t (9,22)( q34.1 ;q11.2 )

Question 22

CML result in chromosome what does it called

Answer 22

Philadelphia

Question 23

Is Philadelphia can be inherited

Answer 23

No

Question 24

APML which chromosome

Answer 24

t(17;15) q(24;21)

Question 25

What happen in APML

Answer 25

Cancer to WBC and bone marrow and accumulation of immature granulocytes