Appunti VERIFICATO
Applied Biology
12 visualizzazioni
13 download
★ 4,0 (1)
Di cosa parla
- Karyotype: ordered display of chromosomes; allows observation of homologous pairs, number, and structure
- Chromosome Structure: arms labeled p (short) and q (long); types include telocentric, acrocentric, submetacentric, metacentric
- Procedure for chromosome preparation from peripheral blood: inoculate whole blood, incubate, add colcemid, incubate, centrifuge, treat with hypotonic solution, fix, stain with Giemsa or Orecin
- Chromosome Banding: identifies segments using dyes; high resolution methods distinguish up to 850 bands per haploid set
- Amenorrhea vs CVS: Amniocentesis at 14-16 weeks, cells cultured for tests; CVS at 8-12 weeks, immediate testing of chorionic villus tissue; FISH for gene localization and chromosome alterations
- Chromosomal Anomalies: numerical (aneuploidies) and structural; aneuploidies include Down, Patau, Edwards syndromes; structural anomalies involve deletions, duplications, inversions, translocations
- Williams syndrome: micro-deletion of chromosome 7q11.23; features include heart defects, facial abnormalities, psychomotor retardation, visual and dental disorders
- Cri-du-chat syndrome: partial deletion of chromosome 5p; characterized by cry, microcephaly, facial abnormalities, psychomotor retardation
- Reciprocal translocation: segments exchanged between non-homologous chromosomes; can lead to Burkitt lymphoma and other cancers
- Robertsonian translocation: common in newborns, involves acrocentric chromosome fusion; carriers may have normal phenotype but issues with gamete formation
- Nondisjunction: failure of chromosome separation during meiosis; leads to aneuploidies like Down's, Edwards', Patau's syndromes and sex triploidy, monosomy Turner syndrome