Chromatin chromosome Sex chromatin Lyon hypothesis(1961) 1. Inactivation of all but one x chromosome 2. Happened at an early stage of embryogenesis 3. Happened on a random basis and maintained in all descendant cells Dosage compensation
Sex chromotin Lyon hypothesis (1961) 1. Inactivation of all but one X chromosome 2. Happened at an early stage of embryogenesis 3. Happened on a random basis and maintained in all descendant cells Dosage compensation Chromotin & Chromosome
Chromatin chromosome Sex chromatin Y-chromatin
Sex chromotin Y-chromatin Chromotin & Chromosome
Sex Determining Mechanism Chromosomal mechanisms(XY &o Two sex chromosomes of different sizes, X is larger . Females are XX males are Xr g Males determine the sex of the offspring Y chromosome TDF: testis-determining factor & SRY: sex-determining region of Y chromosome
Sex Determining Mechanism Chromosomal mechanisms (XY) Y chromosome ❖ Two sex chromosomes of different sizes, X is larger ❖ TDF：testis-determining factor ❖ SRY：sex-determining region of Y chromosome ❖ Females are XX, males are XY ❖ Males determine the sex of the offspring
Molecular basis of genetics
Molecular Basis of Genetics
Structure of dna P Deoxyribose bp A T GC
bp P A T G C Structure of DNA Deoxyribose