This conclusion was reached because no one from Generation I was affected with the disease. However, in Generation II the first male was unaffected with the disease, but the second male was infected with the disease. This proves that it is passed as a recessive trait rather than a dominant trait. This is possible when both parents are hybrids for the trait; which means that they do not have the disease, but carry the gene. Children of two hybrid parents can inherit a recessive gene from each parent.
Note that in all possible cases, each child has an O allele in addition to his/her phenotypic blood expression. A and B are dominant alleles when paired with an O allele and co-dominant when they appear together in the genotype AB. On the other hand, allele O is recessive; therefore both parents must contribute an O allele for their offspring to express type O blood. What possible genotypes result from both parents having type AB blood? | |A |B | |A |AA |AB | |B |AB |BB | This case reveals the two remaining possible genotypes, AA and BB, which express type A blood and type B blood respectively.
2. What might determine whether a person who shows the dominant characteristic is homozygous dominant or heterozygous? When a person shows a dominant trait, their genotype can be homozygous dominant or heterozygous. Homozygous dominant genes are usually noted as two capital letters, while heterozygous genes have one capital and one lowercase letter. This signifies that in heterozygous genes, there is one dominant gene and one recessive, while homozygous genes are both either dominant or recessive.
However, most first degree relatives and twins share the same or similar environments so it is difficult to separate genetic and environmental influences. Because of the difficulties of disentangling genetic and environmental influences for individuals who share genes and environment, studies of genetically related individuals who have been reared apart are used. Tienari et al conducted a longitudinal study and found that out of 164 adoptees whose biological mothers had been diagnosed with schizophrenia, 11 (6.7%) also received a diagnosis of schizophrenia, compared to just four (2%) of the 197 control adoptees (born to non- schizophrenic mothers). This suggests that genes rather than the environment have caused the disorder in these cases. It supports the
Dominant genetic disorders mean that only one parent needs to carry the disorder in order for an offspring to have it, and quite often, that parent also has the disease/disorder as well. For offspring, there is a 50/50 chance of inheritance of a disorder, and if they do NOT inherit the mutation, then they will NOT pass it along to their offspring. A good example of this would be Huntington's disease. http://www.nlm.nih.gov/medlineplus/ency/article/002049.htm Recessive genetic disorders mean that both parents need to carry this trait,
Tay-Sachs Disease “A genetic disorder is a disease that is caused by an abnormality in an individual's DNA. Abnormalities can range from a small mutation in a single gene to the addition or subtraction of an entire chromosome or set of chromosomes” (Genetic). One genetic disorder is Tay-Sac Disease which is caused by a genetic defect that is passed from parent to child. Tay-Sachs disease is a autosomal recessive disease characterized by an abnormal accumulation of certain fat compounds in the spinal cord and brain. Inheritance of Tay-Sachs Children can get this disease if both parents are carrier of Tay-Sachs than the baby can inherit the disease from each of them.
How does the term differ from ethnicity? The term race refers to one’s biological features, significant physical features that are shared within a certain group of people. (p’s 12-14 text1) A few common examples of race include White English settlers, Asian’s and Indigenous Australian’s (Aboriginals). (p 1 text 1) Most of the above are almost always distinguishable from each other by identifiable physical characteristics such as the features within their faces, eyes, hair and build. (p 14 text 1) There are many ways in which ethnicity differs from race; ethnicity unlike race refers to not a person’s biological features, but characteristics that as human beings they are born into and taught to assimilate with examples include the sharing of one’s language, culture, history, food and dress.
Fragile X Syndrome is a prevalent genetic disorder. Other than Down’s syndrome, Fragile X is currently the leading cause of hereditary mental retardation. Even though it is considered a male dominant condition, fragile X does influence females and has many effects on the social, emotional, educational, and family aspects of life. Characteristics of Fragile X Fragile X is an inherited developmental disability and is named from the mutation of the X chromosome, causing a fragile site to appear. Many females will be carriers of this gene due to the presence of two X chromosomes making chances of inheritance of this abnormality half, while the male has only one X chromosome and therefore acquires the syndrome.
A chromosome is a tiny structure that contains the genes we inherit from our parents. Because of the deleted chromosome the hypothalamus region of the brain does not function correctly. The hypothalamus is one of the control centers for the nervous system. This part of the brain is suppose to let the person know when the stomach is full. Because the hypothalamus is not doing its responsibility the individual will never have the feeling of being full.
However, some of these later groups were born by fathers who are older that 60 years. This indicates a possible increase in epigenetic damage in the spermatogenesis of older men than the young and the possibility of other etiological theories. The twin and adoption studies are main evidence that supports a genetic etiology of Schizophrenia. Currently, there is no model of genetic transmission of Schizophrenia. However, further evidence for genetic etiology of Schizophrenia has arisen with the linkages and