Sex Related Genetics:
Sex Related Genetic Effects:
Some genes may have different effects depending on an individual's gender. These are referred to as sex-limited genes, sex-controlled genes and genomic imprinting. Sex-limited genes are inherited by both genders but is usually expressed in the phenotype of one of them. The heavy male beard is an example, while women have facial hair it is most often very fine and comparatively sparse. Sex-controlled genes are expressed in both sexes but differently. An example is gout, a disease that causes painful joints, which is more likely to be more severe for men. Genome imprinting is when a gene has a different effect depending on the gender of the parent from whom it was inherited.
Pleiotropy: Pleiotropy is when a single gene is responsible for a variety of traits. A pleiotropic trait is albinism. People with albinism have little or no pigment in their eyes, skin, or hair. They have inherited altered genes that do not make the usual amounts of a pigment called melanin. Identical twins would either both be albino or not.
Stuttering Alleles: Stuttering or unstable alleles are defective alleles that have segments which are doubled in their transmission from generation to generation. Each generation has increasingly severe symptoms. Muscular dystrophy is a condition which weakens a person's muscles and can be worse each generation. This is an example of Stuttering Alleles.
Environmental Influences: The phenotype or physical characteristics of an individual is not only the result of inheriting a particular set of parental genes. Specific environmental characteristics of the uterus in which a fertilized egg is implanted and the health of the mother can have major impacts on the phenotype of the future child. In addition, accidents, poor nutrition, and other environmental influences throughout life can alter an individual's phenotype for many traits. If there are any differences in the phenotypes of identical twins, the environment is virtually always responsible.
Some genes may have different effects depending on an individual's gender. These are referred to as sex-limited genes, sex-controlled genes and genomic imprinting. Sex-limited genes are inherited by both genders but is usually expressed in the phenotype of one of them. The heavy male beard is an example, while women have facial hair it is most often very fine and comparatively sparse. Sex-controlled genes are expressed in both sexes but differently. An example is gout, a disease that causes painful joints, which is more likely to be more severe for men. Genome imprinting is when a gene has a different effect depending on the gender of the parent from whom it was inherited.
Pleiotropy: Pleiotropy is when a single gene is responsible for a variety of traits. A pleiotropic trait is albinism. People with albinism have little or no pigment in their eyes, skin, or hair. They have inherited altered genes that do not make the usual amounts of a pigment called melanin. Identical twins would either both be albino or not.
Stuttering Alleles: Stuttering or unstable alleles are defective alleles that have segments which are doubled in their transmission from generation to generation. Each generation has increasingly severe symptoms. Muscular dystrophy is a condition which weakens a person's muscles and can be worse each generation. This is an example of Stuttering Alleles.
Environmental Influences: The phenotype or physical characteristics of an individual is not only the result of inheriting a particular set of parental genes. Specific environmental characteristics of the uterus in which a fertilized egg is implanted and the health of the mother can have major impacts on the phenotype of the future child. In addition, accidents, poor nutrition, and other environmental influences throughout life can alter an individual's phenotype for many traits. If there are any differences in the phenotypes of identical twins, the environment is virtually always responsible.