Non-Mendelian Inheritance PDF

Non-Mendelian inheritance refers to the inheritance of traits that have a more complex genetic basis than one gene with two alleles and complete dominance. Mendelian Genetics describes inheritance patterns based on Complete Dominance or Recessiveness. There are other types of inheritance that Men...

Non-Mendelian inheritance refers to the inheritance of traits that have a more complex genetic basis than one gene with two alleles and complete dominance. Mendelian Genetics describes inheritance patterns based on Complete Dominance or Recessiveness. There are other types of inheritance that Mendel never considered: Incomplete dominance is a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype. It is also known as partial dominance. CARNATION FLOWER Sample Problem: A pink-flowered plant is crossed with a white-flowered plant. Show the Punnett Square. What is the probability of producing a pink-flowered plant? 𝑪𝑾 𝑪𝑾 𝑪𝑹 𝑪𝑹 𝑪𝑾 𝑪𝑹 𝑪𝑾 𝑪𝑾 𝑪𝑾 𝑪𝑾 𝑪𝑾 𝑪𝑾 Probability of Pink Flower: 50% Codominance, as it relates to genetics, refers to a type of inheritance in which two versions (alleles) of the same gene are expressed separately to yield different traits in an individual. COW’S FUR Sample Problem: 1. In some chickens, the gene for feather color is controlled by codominance. The allele for black is 𝑭𝒃 and the allele for white is 𝑭𝒘. The heterozygous phenotype is known as erminette (black and white spotted). A black chicken and a white chicken are crossed. Show the Punnett Square. What is the probability that they will have erminette chicks? 𝑭𝒘 𝑭𝒘 𝑭𝒃 𝑭𝒃 𝑭𝒘 𝑭𝒃 𝑭𝒘 𝑭𝒃 𝑭𝒃 𝑭𝒘 𝑭𝒃 𝑭𝒘 Probability of producing Erminette chicken: 100% In biology, multiple alleles are three or more alleles controlling a particular gene. Multiple allelism: The condition of the presence of multiple alleles. ABO Blood Group System ABO Blood Group System Sample Problem: There is a practical joker in the maternity ward who removed all the baby id bracelets. There are three babies that cannot be easily distinguished, and the parents want to be sure they get the right ones back, so the doctors do a blood test. A particular mom is homozygous type A and the dad is type O. The babies have blood types AB, A, and O. Show your work below and indicate which baby must be theirs. i i 𝐈𝐀 𝐈𝐀i 𝐈𝐀i 𝐈𝐀 𝐈𝐀i 𝐈𝐀i Correct Baby: 𝐈 𝐀i A polygenic trait is a characteristic, such as height or skin color, that is influenced by two or more genes. Because multiple genes are involved, polygenic traits do not follow the patterns of Mendelian inheritance. Many polygenic traits are also influenced by the environment and are called multifactorial. Pleiotropy Some genes affect more than one phenotypic trait. Some genes affect the expression of other genes. A person with albinism has virtually no pigment in the skin. The condition occurs due to an entirely different gene than the genes that encode skin color. Albinism occurs because a protein called tyrosinase, which is needed for the production of normal skin pigment, is not produced, due to a gene mutation. REFERENCES https://humanbiology.pressbooks.tru.ca/chapter/5-13-non- mendelian-inheritance/ https://byjus.com/biology/non-mendelian- inheritance/#:~:text=Non%2Dmendelian%20genetics%20invol ves%20the,match%20up%20with%20Mendel's%20laws. 1. You are blood type O and you marry a person with blood type AB. A. Draw a Punnett square for the cross. B. List the possible blood types (phenotypes) of your offspring. 2. Basic body color for horses is influenced by several genes, one of which has several different alleles. Two of these alleles – the chestnut BC (dark brown) allele and a diluting (pale cream) allele Bc (often called albino) – display incomplete dominance. A horse heterozygous for these two alleles is a palomino BCBc (golden body color with flaxen mane and tail). Work the Punnett’s square for mating a palomino to a palomino and predict the phenotypic ration among their offspring. 3. In rabbits, white coat color (CW) and black coat color (CB) are codominant, and both of these alleles are dominant over albino (c); heterozygotes (CWCB) are spotted. Draw a Punnett square that shows the genotypes and phenotypes of the offspring from heterozygous black - coated rabbit and a homozygous white-coated rabbit? 4. Skin color in human is determined by a polygenic inheritance system, possibly involving as many as 9 genes. For simplicity let’s consider the influence of 2 genes: A and B, where the dominant allele darkens skin color. Suppose a woman who is AABb mates with a man who is Aabb. List all of the possible genotypes of the gametes that could be produced by each the parents. Identify the ratios.