Sex-linked inheritance
There are two types of chromosomes in living organisms i.e autosomes and sex chromosomes.autosomes bear genes for somatic organ nd sex chromosome to deermine sex of a individual.most female have two rod shaped xx chromosomes and male have a rodshaped and other hooked shaped xy chromosomes.
genes located in x-chromosomes are sex linked genes and pattern of inheritance of such gene is called sex-linked inheritance.
sex genes usually are inherited along with x-chromosomes . usually y chromosomes are genetically inert.genes of y-chromosomes are called holandric genes.
CHARACTERISTICS
1. The y-chromosome donot carryany homologous region of x-chromosomes.male have only one x-chromosome and so a trait expresses even if it is present in recessive form.
2.A female have two x-chromosome and so has to become homozygous to express a recessive trait.that means she must receive mutant allele from both parents.
3.A female receives one x-chromosome from her father which she subsequently transmit to her children,meaning that her children would get the grandfather's sex-linked trait.
4.A male transmits his sex-linked traits to his grand children via his daughter.this is called criss-cross inheritance.
5.A father cannot transmit sex-linked traits to his son because x-chromosome of son is always from the mother.
6. From a female,sex-linked gene goes both to son and daughters.
7.In all sex-linked traits,heterozygous females are the carriers .they are phenotypically normal but carry the trait in the genes.
8. The recessive x-linked disease are seen more in male than in female.
There are two types of chromosomes in living organisms i.e autosomes and sex chromosomes.autosomes bear genes for somatic organ nd sex chromosome to deermine sex of a individual.most female have two rod shaped xx chromosomes and male have a rodshaped and other hooked shaped xy chromosomes.
genes located in x-chromosomes are sex linked genes and pattern of inheritance of such gene is called sex-linked inheritance.
sex genes usually are inherited along with x-chromosomes . usually y chromosomes are genetically inert.genes of y-chromosomes are called holandric genes.
CHARACTERISTICS
1. The y-chromosome donot carryany homologous region of x-chromosomes.male have only one x-chromosome and so a trait expresses even if it is present in recessive form.
2.A female have two x-chromosome and so has to become homozygous to express a recessive trait.that means she must receive mutant allele from both parents.
3.A female receives one x-chromosome from her father which she subsequently transmit to her children,meaning that her children would get the grandfather's sex-linked trait.
4.A male transmits his sex-linked traits to his grand children via his daughter.this is called criss-cross inheritance.
5.A father cannot transmit sex-linked traits to his son because x-chromosome of son is always from the mother.
6. From a female,sex-linked gene goes both to son and daughters.
7.In all sex-linked traits,heterozygous females are the carriers .they are phenotypically normal but carry the trait in the genes.
8. The recessive x-linked disease are seen more in male than in female.
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