Human chromosome 1

Cytogenetics
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Terms in this set (21)
Cytogenetics
The study o structure and unction o chromosomes and their behaviour durin somatic and ermline division.
Molecular genetics
The study o structure and unction o enes at a molecular level and how enes are transerred rom eneration to another.
Non-Banded Karyotype
● Banded Karyotype
● Hih resolution Karyotype
Techniques that use it in cytogenetics
Fluorescent in situ hybridisation FISH
Techniques that use it in the molecular genetics
Two types noninvasive ( NIPT ) and invasive
Types of prenatal diagnosis
Prenatal dianosis: Two types noninvasive ( NIPT ) and invasive Certain patients with mental retardation and multiple
birth deects.
Patients with abnormal sexual development.
Some cases o inertility or multiple miscarriaes.
In the study and treatment o patients with malinancies & hematoloic disorders.
Chromosome studies are an important laboratory dianosis in:
Carry genetic material


Heredity: each pair of homoloues consists o one paternal and one maternal chromosome
Why the chromosome is important and the structure of chromosome
Decreasing
Glasses of chromosomes numbered by order of ....... Length
DNA double helix

Chromatin fiber
Around histones (basic proteins) → nucleosomes


Chromatin fibers orm lon loops on non-histone proteins → tihter coils
The chromosome consist of
prophase
Chromosomes develop in mitotic phase....
10-12 6-8 2-4G1......./ S......../.........G2......../M.......Two sister chromatids are held together at the centromeric Each chromosome has a centromere (CEN), reion which contains the kiretochore CEN divides the chromosome into two arms: ● short arm (P arm) ● lon arm (Q arm) Each arm terminates in a telomereExplain the metaphase chromosomeThe ratio o the lenths o the two arms is constant or each chromosome. This ratio is an important parameter or chromosome identification and allows classification o chromosomes into several basic morpholoic types:Important thingmetacentric : Has a loner arm. 2-sub-metacentric : Has a shorter arm. 3-acrocentric : Has no arm. I n the human karyotype chromosome pairs 13, 14, 15, 21, 22 are acrocentric.Give the three centromeres position and arm length and examplesCulture media contains phytohemagglutin for 3 days to stimulate T lymphocytes to divide 37 degree Colchicine with hypotonic to arrest the cell division and prevent formation spindle Drop of water Trypsin And GiemsaThe function of phtohemagglutin and colchicine and how can we study the chromosomes under the microscope46, XY 46, XX Abnormal Karyotypes 47,XY,+ 21 - Down Syndrome 45,X - Turner SyndromeNormal type and abnormal type ()Culturin Harvestin Stainin Karyotypin Karyotypin is based on: KEEP IN MIND Slide-Makinsteps involved in karyotypin:The lent The position o the centromere The presence or absence o satellitesKaryotypin is based onBatterings are specific and repeatable for chromosome Bands help us to identification The longitudinal mapping , the location and the characteristics genes Each arm presentin a sequence o dark and light bands.Explain the bandingG R Q C —— G Dark; non-active LIGHT ; active Treat with trypsin and then with Giemsa Stain ——— R light; non-active Dark; active Heat and then treat with Giemsa Stain ———- Q Treat with Quinicrine dye giving rise to fluorescent bands. It requires an ultraviolet fluorescent microscope ——- C Stainin o the Centromere. Treat with acid ollowed by alkali prior to G bandinTypes of bondingMetaphase interphaseWe use FISH IN ......phase .......phase