(key: Chromo(s) - Chromosome(s))
Sex inheritance in humans
- sex determined by chomosomes
- females: 2X chromosomes, all female gametes are the same having X's
- males : 1X, 1Y producing two types of gamete- 50% X , 50% Y
sex linkage - Haemophilia:
- any gene carried on X/Y chromos are sex linked
- X is longer than Y so on most of X's length, there is no equivilent homologous portion of the Y chromosome.
- those characteristics conrolled by recessive alleles on the non homologous part of the X appears frequently in Males.
- there is no homologous portion on Y which may carry a dominant allele.
- X chromos carries many genes
- in haemophilia, blood clots slow, and has slow constant jointal bleeding.
- this resulted…