A diploid organism has two alleles for every gene. These alleles are each copied

Question

A diploid organism has two alleles for every gene. These alleles are each copied (during DNA replication) and separated (through meiosis) so that one allele goes into each haploid gamete. The fact that alleles separate from each other to sort individually into gametes is an example of the law of segregation. A single gamete from one individual combines with a single gamete from another individual (during ferti ization) to create, once again, one diploid cell with two alleles. The indlviduals that provide the gametes are known as the parents, and the cell or cells that result from fertilization are known as offspring If the genotypes of two parent organisms are known, it is possible to calculate the possible genotypes and phenotypes that w be present in the offspring. A simple way to visually represent this is through the use of a Punnett square. The simplest Punnett squares observe a single gene in the parents and offspring. The folowing Punnett square displays the gene for color in tigers. In this example, the allele for orange color (T) is dominant to the allele for white color (t). The genotype of each parent is shown, along with an image portraying the phenotype. Complete the Punnett square to show the possible offspring these two individuals could have. (Hint: Click the link "Info on Punnett Squares" if you need more information on how to fill in and interpreta Punnett square.) Info on Punnett Squares 50%, these two parent tigers have just one offsgpring, there is a chance that the offpring will be erange and hance ta the offspring will be white. Human blood type is an example of a multiple allele system, since it has more than two possible alleles for the same gene. The three different alleles are cated A, B, and 0. The A and B alleles are codominant;?both alleles are present, both are expressed in the phenotype of the individual. The O allele is recessive to both A and B. (Note Even though O represents a recessive alilele, it is frequently listed with a capital letter In the following chart, select the correct phenotype for each listed genotype. Genotype Phenotype (Blood type) Tyee AD AO Just like all other alleles, blood type alleles sort themselves into gametes according to Mendelian genetics. Thus when two individua's with given blood types have a child together, there are a limited number of blood type possibilities for the child. Because of this, simple patemity tests use blood type to rule out the possibility for a certain man to be the father of a certain child Imagine you are a genetic counselor asked to help settle a paternity dispute. Before ordering an expensive DNA test, you decide to first try a simple blood type test. The mother's blood type has the genotype Ao, and the supposed father's blood type has the genotype B8. You do not know the genotype of the child, but the phenotype of the child is type A. After completing a simple Punnett square using the parent's blood type genotypes, you can condude that it possible that this man is the father of this child. 1S

Explanation / Answer

Q1) Alelle for orange color tiger is (T) it is dominant , white color tiger is (t) it is recessive.

When Tt crossed with tt the punette square will be

If these two parent tigers have one offspring there is 50% chance of offspring becoming orange and 50% chance of offspring becoming white.

because the two genotypes are in 1:1 ratio , and as T is dominant over t or white color , when they are present in heterozygous condition the phenotype of offspring will be Orange , and when t is in homozygous that is both alleles from each parent contains t than it is white in color.

Q2) ABO blood type-

About the phenotype and genotype of blood

Genotype AA & AO give rise to A blood group as A is dominant over O , AB are codominant , when present they expresss both the genes so AB genotype will be AB blood group.

Q3) In the paternity test Mother's blood type is AO, supposed father's blood type is BB, the offspring to be tasted is A blood group .

AO has A and O gene , BB has B gene, when AO crossed with BB -----> AOXBB----> Offspring is AB, B.

so in the punette square

When AO mother crossed with BB father the offspring will be AB, BB. but in the question the child whose paternity test is done is Phenotypically A blood group , so the man who is suspected is not the father of the child.

*Genetic counsellor concludes that it is not possible that this man is the father of the child.

t t T Tt (Orange as T is dominant over t) Tt (Orange as T is dominat over t) t tt(White as it is homozygous recessive) tt(White as it is homozygous recessive)

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