Genetics: Quiz Ii Cytogenetics

Front 1

If trying to rule out mosaicism then?

Back 1

Use two different tissue samples for analysis

Front 2

What are some suitable cells that can be submitted for cytogenetic studies?

Back 2

1. Lymphocytes found in blood (peripheral blood)
2. Fibroblasts from skin & tissue biopsies
3. Bone marrow cells
4. Fetal cells (amniotic fluid or from chorionic villus biopsies)

Front 3

How do we grow cells that will be used for cytogenetic studies?

Back 3

1. Mitogens are added to stimulate cells to divide
2. Incubate for 2-3 days
3. Cocemid is added to stop mitosis in metaphase
4. Centrifuge cells to concentrate
5. Add a hypotonic solution and fix cells, then drop cells on slide to break them
6. Add trypsin to digest proteins associated with DNA
7. Add Giemsa stain

Front 4

There are 2 types of banding techniques

Back 4

1. Techniques that produce thin, alternating bands along the length of the entire chromosome (G, Q, R)

2. Techniques that stain onl y a specific band or region of some or all of the chromosomes (C, T, NOR, DAPI)

Front 5

What banding stains constitutive heterochromatin?

Back 5

C banding

Front 6

How do these stain with the Geimsa stain?

Euchromatin, constitutive heterochromatin, & facultative heterochromatin

Back 6

Euchromatin: stains G negative

Constitutive heterochromatin: stains G positive

Facultative heterochromatin: stains either G+ or G-

Front 7

Term that indicates a cell with a set or sets of 23 chromosomes

Ie: haploid, diploid, polyploid

Back 7

Euploid

Front 8

Term that indicates exact multiples of the haploid chromosome number, greater than diploid

Ie: triploidy, tetraploidy

Back 8

Polyploidy

Front 9

Any other abnormal chromosome number (not in sets of 23)

Ex: Trisomy, Monosomy

Result of nondisjunction

Back 9

Aneuploidy

Front 10

Failure of chromosomes to separate normally during cell division either meiosis or mitosis

Back 10

Nondisjunction