For X chromosomes, human females have a pair of allels on the pair of X-chromosomes. But, for traits present on X chromosomes, human males have only one of the alleles. What is this mechanism known as?
For X chromosomes, human females have a pair of allels on the pair of X-chromosomes. But, for traits present on X chromosomes, human males have only one of the alleles. What is this mechanism known as?
I would like to clarify you that there is not any special mechanism involved in this .
The two allelic forms of a gene are present on two homologous chromosomes.
In case of males:-Males don't have homologous chromosomes.They have one X & one Y chromosome (XY). So, allelic form of a particular gene present on X is not present on the Y chromosome. Y chromosome is transferred as it is from father to son. If a gene is present in dominant condition on X chromosome then during the transfer of traits, it will express itself only in heterozygous condition and if a gene is present in recessive condition then it will not express itself in any of the condition. In order to express itself in recessive state, it needs other allelic form which is actually not present in case of heterozygous chromosomes
In case of females:-Females have homologous chromosome each having one allelic form of a gene. If a gene is present in dominant condition then during the transfer of traits , it will express itself in both homozygous & heterozygous conditions. But, if it is present in recessive form then it will express only in homozygous condition. Its because female have both allelic forms of a gene.
I would like to clarify you that there is not any special mechanism involved in this .
The two allelic forms of a gene are present on two homologous chromosomes.
In case of males:-Males don't have homologous chromosomes.They have one X & one Y chromosome (XY). So, allelic form of a particular gene present on X is not present on the Y chromosome. Y chromosome is transferred as it is from father to son. If a gene is present in dominant condition on X chromosome then during the transfer of traits, it will express itself only in heterozygous condition and if a gene is present in recessive condition then it will not express itself in any of the condition. In order to express itself in recessive state, it needs other allelic form which is actually not present in case of heterozygous chromosomes
In case of females:-Females have homologous chromosome each having one allelic form of a gene. If a gene is present in dominant condition then during the transfer of traits , it will express itself in both homozygous & heterozygous conditions. But, if it is present in recessive form then it will express only in homozygous condition. Its because female have both allelic forms of a gene.
