Chap 13 Flashcards
Chromosomes (27 cards)
Cytogenetics
Classical area of genetics that links chromosome variations to specific traits, including illness
Heterochromatin
- Short arm
- Dark staining
- Repetitive DNA
Euchromatiin
- Long arm
- Lighter staining
- Protein-coding genes
Telomeres
- Chromosome tips
- Short after cell division
-> Apoptosis
Karyotype
- Chromosome chart
- Performed during mitotic metaphase.
Telocentric
Centromere at the tip
Acrocentric
Centromere close to center
Submetacentric
Centromere off-center
Metacentric
Centromere at the center
How to detect Chromosome in blood
- Any cell that has a nucleus
- Def not red blood cell
Amniocentesis
- Amniotic fluid from uterus.
Chrorionic Villus Sampling
- 10-12th week of pregnancy
- Tissue sample from placenta
- Big risk abortion
- Does not detect metabolic problems.
- Faster result than Amnio
Cell-Free Fetal DNA testing
- 10 weeks or later of pregnancy
- Non-invasive
- Blood sample
- 20% of mother’s blood (DNA)
Chromosomal Shorthand
Describe structure, number or any abnormalities of chromosome in karyotype.
Euploidy
Complete set of chromosome or extra
- Types:
-Haploidy (n)
-Diploidy (2n)
-Triploidy (3n)
-Polyploidy
Polyploidy
Extra chromosome sets
Aneuploidy
Add or loss of 1 chromosome number
Not the whole set
Nondisjunction
- Create gamete with extra chromosome and another with loss chromosome.
- During Meiosis 1 and 2
Trisomy 21
- Down syndrome
- Facial and physical problem
- 80% survival rate
Trisomy 18
- Edwards syndrome
- Nondisjunction in meiosis 2
- Do not survive
-Mental and
physical disabilities
Trisomy 13
- Patau syndrome
- Rare
- 6 months
- Intellectual disability and physical disability
Sex chromosome Aneuploid
- More common than autosomal
- At least 1 copy of X for survival
XO, 45
-Turner Syndrome
- Female
- Short
- Infertility
- Webbing neck
XXY, 47
- Klinefelter Syndrome
- Male
- Infertility
- Long limbs, large hand and feet
