Patterns of Transmission of Characteristics and Definition of Heterozygous and Homozygous is, When the person inherits identical alleles he is said to be “homozygous” (possessing two identical alleles for a trait). When he inherits two different alleles then the person is “heterozygous” (possessing two different alleles for a trait).
Example of Heterozygous and Homozygous: when a person is homozygous for brown eyes then he will transmit only genes for brown eyes to his offspring and if heterozygous for blue and brown eyes then although dominant one is brown, but he will transfer his both alleles to his offspring.
Autosomal Dominant Inheritance
• Patterns of inheritance in which a specific gene is dominant; if it is inherited; it manifests itself in the person. Autosomal Recessive Inheritance
• Patterns of inheritance in which trait appears only if a person inherits two genes for it, one from each parent. If the person inherits only one gene for a trait, it will not appear in a person but may be passed on to his children.
Multi- Factorial Inheritance
• Patterns of inheritance in which a trait is expressed either by a combination of several genes or through the interaction of genes with environmental factors.
• More complicated combination of genes or an interaction between genetic predispositions and environmental factors that bring them out.
• Some characteristics follows one of these patterns, other genes another.
Hair type (curly or straight) is either autosomal dominant or autosomal recessive, baldness is sex- linked; height and weight are probably multi- factorial. Some diseases and birth defect are inherited according to these
Patterns Most prominent examples are:
Achondroplasia: a kind of dwarfism that is inherited by autosomal dominance. Tay- Sachs disease: body’s inability to break down fat; results into death by 3-4 years of age
Huntington’s disease: 99.9% correlation between having the identified gene and the disease.
The blood- clotting disorder hemophilia is a sex- linked condition.
Spina bifida: a defect in the closure of the vertebral canal that is believed to be the condition as Heterozygous and Homozygous transmitted by sex- linked inheritance The process of development continues throughout the life span While considering aspects of development, individuality and interactions are the key terms in understanding it. All beings bring their unique genetic package into this world and have unique sets of experiences too. An individual’s strengths, abilities, and predispositions are affected by the influence of environment. These influences make a person act in ways that elicit new experiences