In: Biology
Balding and color blindness are genetic mutations that occur more frequently in males than females. This is because its a _______________ trait
recessive |
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dominant |
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sex linked |
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polyploidy |
The correct option is 'Recessive'
In Sex linked traits, the genes are located on a sex chromosome. A dominant trait is phenotypically expressed in heterozygotes whereas a recessive trait is phenotypically expressed only in homozygotes. Polyploid organisms contain more than two sets of chromosomes.
Balding and color blindness are X- linked (genes are present on X chromosomes) recessive traits and in a man, one altered copy of the gene is sufficient to cause the conditions. But a woman is bald (or color blind) only if both the copies of genes are altered in cells. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). A woman can have one X chromosome with the mutant gene and one X chromosome with a normal gene. As Balding and color blindness are recessive, the dominant normal genes will mask the recessive mutant genes in heterozygous females to make them carriers.
On the other hand, females would display dominant, X-linked traits with greater frequency than males as only one altered copy of the gene in each cell is sufficient to cause them.