p 3

Question 1

karyotyping is used for what ?

Answer 1

karyotyping is a cytogenetic techniue that used to analyze the chr for any structural or numerical abnormalities

Question 2

in which stagei s karyotyping preformed?

Answer 2

in metaphase stage of mitosis in this stage each of the 2 sister chromatids contain a highly coilrd double helix of DNA

Question 3

what are type of cell used for karyotyping?

Answer 3

1- peripheral blood [طرفيه]

2-bone marrow

3-amniotic fluid

Question 4

why white blood cell are usually used for karyotyping ?

Answer 4

bcz they have nucleus

Question 5

preparation of cell for karyotyping include?

Answer 5

add colchicine to stop cell division at metaphase stage

collect cell and add hypotonic solution [تفجر الخليه عشان تطلع الكروموسومات]

fix cell with methanol or acetic acid

trear cell with trypsin

stain the slides in giemse stain

use light microscope 40%

Question 6

what is the abnormality in chr?

Answer 6

1- trisomy 21 [down syndrome] ….extra one chr 21

2-klinefelter syndrome …..extra one X chr [sex chr]