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Flashcards in L.2 Deck (25)
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1
Q

What is the chromatin structure?

A

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

2
Q

Explain Euchromatin ?

A

Active , unmethylated cytosines and acetylated histones

3
Q

Explain Heterochromatine ?

A

Condensed , methylated cytosine and deacetylated histones

4
Q

Conventional cytogenetics can detect chromosomal changes size what ?

A

Less than 5 Mb

5
Q

What are the two categories of chromosomal structural abnormalities?

A

Balanced and unbalanced

6
Q

How can u differentiate between balanced and unbalanced chromosomal changes?

A

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

7
Q

Structural chromosomal abnormalities is inheritable if it’s where ?

A

Germ line

8
Q

What are the two types of deletion ?

A

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

9
Q

Give examples for large and small deletion ?

A

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

10
Q

What are the types of chromosomal structural abnormalities?

A

Deletion
Duplication
Inversion
Translocation

11
Q

What happen in inversion ?

A

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

12
Q

Example of inversion

A

Haemophilia A gene 8 Chr 22

13
Q

What are the two types of translocation

A

Reciprocal translocation
Robertsonian translocation

14
Q

What is reciprocal translocation

A

When two chr swap non-homologous sections

15
Q

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

A

No stay the same so it’s balanced

16
Q

What happen in robertsonian translocation?

A

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

17
Q

Why does change in the robertsonian translocation

A

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

18
Q

Dawn syndrome which type of chromosomal abnormalities

A

Robertsonian translocation

19
Q

Which chromosome involved in Dawn syndrome

A

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

20
Q

What happen in the balanced structural abnormalities of chromosome

A

DNA packaged is incorrect and phenotype is normal

21
Q

CML which chromosome

A

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

22
Q

CML result in chromosome what does it called

A

Philadelphia

23
Q

Is Philadelphia can be inherited

A

No

24
Q

APML which chromosome

A

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

25
Q

What happen in APML

A

Cancer to WBC and bone marrow and accumulation of immature granulocytes