The Study of The Pedigree
Scientists have devised another approach, called pedigree analysis, to study the inheritance of genes in humans. Pedigree analysis is also useful when studying any population when progeny data from several generations is limited. Pedigree analysis is also useful when studying species with a long genration time. There are a series of symbols that are used to represent particular factors or traits of a human
Dominant and Recessive Pedigree
Below are some images of pedigrees that contain dominant and recessive traits
Below are some images of pedigrees that contain dominant and recessive traits
To fin out more information on characteristics of these pedigrees visit: http://www.ndsu.edu/pubweb/~mcclean/plsc431/mendel/mendel9.htm
Watch the video to find out how to solve a genetic pedigree: http://www.youtube.com/watch?v=HbIHjsn5cHo
This interactive game shows how a particular animal can be bred based one genetic trait: http://pbskids.org/dragonflytv/games/game_dogbreeding.html
Watch the video to find out how to solve a genetic pedigree: http://www.youtube.com/watch?v=HbIHjsn5cHo
This interactive game shows how a particular animal can be bred based one genetic trait: http://pbskids.org/dragonflytv/games/game_dogbreeding.html
The probability of inheriting a particular condition
As shown in the inheritance section, there is a probability or chance of an offspring inheriting a particular condition from the parent. As shown in the dominant pedigree above, the parents had one child with the disease and the other two without. This meaning that the mother who was had the trait also carried the recessive gene for example Rr. the male carrying recessive genes (rr). This meaning that their kids could either be Rr, Rr, Rr, rr. There is a 75% chance of carrying the trait but also a 25% chance of carrying recessive genes.
Website: http://anthro.palomar.edu/mendel/mendel_2.htm
As shown in the inheritance section, there is a probability or chance of an offspring inheriting a particular condition from the parent. As shown in the dominant pedigree above, the parents had one child with the disease and the other two without. This meaning that the mother who was had the trait also carried the recessive gene for example Rr. the male carrying recessive genes (rr). This meaning that their kids could either be Rr, Rr, Rr, rr. There is a 75% chance of carrying the trait but also a 25% chance of carrying recessive genes.
Website: http://anthro.palomar.edu/mendel/mendel_2.htm
Making predictions from a pedigree
One of the most frequent reasons for constructing a pedigree for a family is to investigate the pattern of inheritance of a genetic disorder.
Dominant inheritance:
Dominant alleles usually aren't passed on to the offspring because the carrier frequently dies before the opportunity to reproduce. One exception of this is Huntington's disease. The symptoms of this disorder seldom appear before 40 years of age. It is characterised by the flailing movements of the arms and legs. People also may find it hard to make voluntary movements as a result.
To know more about Huntington's disease: http://en.wikipedia.org/wiki/Huntington's_disease
Recessive inheritance:
A person with the recessive allele but does not show the phenotype for it is known as a carrier. If both parents are carriers then the child may become an affected individual. When both parents carry the recessive gene there is a 25% chance that their offspring will be affected by the trait. many diseases that are recessive produce serious abnormalities, one being Phenylketonuria (PKU). The gene that controls the production of an enzyme called phenylalanine hydroxylase.
To learn more about PKU follow this link: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Phenylketonuria_(PKU)
Codominant Inheritance:
Sickle-cell anaemia is an example of codominace. When a homozygous sickle celled individual mates with someone who is a homozygous normal trait then the offspring created will have normally shaped red blood cells unless there is a low concentration of oxygen in the blood. This is known as sickle-cell trait.
http://www.nhlbi.nih.gov/health/health-topics/topics/sca/
One of the most frequent reasons for constructing a pedigree for a family is to investigate the pattern of inheritance of a genetic disorder.
Dominant inheritance:
Dominant alleles usually aren't passed on to the offspring because the carrier frequently dies before the opportunity to reproduce. One exception of this is Huntington's disease. The symptoms of this disorder seldom appear before 40 years of age. It is characterised by the flailing movements of the arms and legs. People also may find it hard to make voluntary movements as a result.
To know more about Huntington's disease: http://en.wikipedia.org/wiki/Huntington's_disease
Recessive inheritance:
A person with the recessive allele but does not show the phenotype for it is known as a carrier. If both parents are carriers then the child may become an affected individual. When both parents carry the recessive gene there is a 25% chance that their offspring will be affected by the trait. many diseases that are recessive produce serious abnormalities, one being Phenylketonuria (PKU). The gene that controls the production of an enzyme called phenylalanine hydroxylase.
To learn more about PKU follow this link: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Phenylketonuria_(PKU)
Codominant Inheritance:
Sickle-cell anaemia is an example of codominace. When a homozygous sickle celled individual mates with someone who is a homozygous normal trait then the offspring created will have normally shaped red blood cells unless there is a low concentration of oxygen in the blood. This is known as sickle-cell trait.
http://www.nhlbi.nih.gov/health/health-topics/topics/sca/
Bacon, L. (n.d.). Genetics-Scientific study of heredity. Retrieved October 6, 2014, from Lord Bacon: http://lordbacon5.blogspot.com.au
Better Health Channel. (n.d.). Genetic Disorders. Retrieved October 6, 2014, from Better Health Channel: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Genetic_disorders
Better Health Channel. (n.d.). PKU. Retrieved October 6, 2014, from Better Health Channel: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Phenylketonuria_(PKU)
Douch, A. (n.d.). How to solve a genetic pedigree. Retrieved October 6, 2014, from YouTube: http://www.youtube.com/watch?v=HbIHjsn5cHo
McClean, P. (n.d.). Pedigree Analysis. Retrieved Octobe 6, 2014, from Mendelian Genetics: http://www.ndsu.edu/pubweb/~mcclean/plsc431/mendel/mendel9.htm
National Heart, Lung and Blood Institute. (n.d.). What Is Sickle Cell Anemia? Retrieved October 6, 2014, from National Heart, Lung and Blood Institute: http://www.nhlbi.nih.gov/health/health-topics/topics/sca/
NIDCD. (n.d.). Usher Syndrome . Retrieved October 6, 2014, from http://www.nidcd.nih.gov/health/hearing/pages/usher.aspx
Sickle Cell Anaemia. (n.d.). Retrieved October 6, 2014, from Creation Studies Institute: http://www.creationstudies.org/operationsalt/sickle_cell_anemia%20.html
wikipedia. (n.d.). Talk:Pedigree chart. Retrieved October 6, 2014, from wikipedia: http://en.wikipedia.org/wiki/Talk%3APedigree_chart
Better Health Channel. (n.d.). Genetic Disorders. Retrieved October 6, 2014, from Better Health Channel: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Genetic_disorders
Better Health Channel. (n.d.). PKU. Retrieved October 6, 2014, from Better Health Channel: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Phenylketonuria_(PKU)
Douch, A. (n.d.). How to solve a genetic pedigree. Retrieved October 6, 2014, from YouTube: http://www.youtube.com/watch?v=HbIHjsn5cHo
McClean, P. (n.d.). Pedigree Analysis. Retrieved Octobe 6, 2014, from Mendelian Genetics: http://www.ndsu.edu/pubweb/~mcclean/plsc431/mendel/mendel9.htm
National Heart, Lung and Blood Institute. (n.d.). What Is Sickle Cell Anemia? Retrieved October 6, 2014, from National Heart, Lung and Blood Institute: http://www.nhlbi.nih.gov/health/health-topics/topics/sca/
NIDCD. (n.d.). Usher Syndrome . Retrieved October 6, 2014, from http://www.nidcd.nih.gov/health/hearing/pages/usher.aspx
Sickle Cell Anaemia. (n.d.). Retrieved October 6, 2014, from Creation Studies Institute: http://www.creationstudies.org/operationsalt/sickle_cell_anemia%20.html
wikipedia. (n.d.). Talk:Pedigree chart. Retrieved October 6, 2014, from wikipedia: http://en.wikipedia.org/wiki/Talk%3APedigree_chart