Certain people are able to taste the chemical phenylthiocarbamide (PTC) when it is present in wet filter paper. These people are called 'tasters'. Others are unable to detect PTC and have the 'nontaster' phenotype. PTC tasting is an example of variation in sensory perception, and the genetic basis is thought to be rather simple. The ability to taste PTC is attributed to a dominant allele, denoted T, located on chromosome 7. The recessive allele is designated t. From analysis of pedigrees, 259 taster children and 278 non taster progeny were observed where one parent was heterozygous and could 'taste' PTC and the other parent was a 'nontaster'. Does this data set support the suggestion that his variation is due to a simple Mendelian pattern?

a. Each person inherits one copy of the Huntington's Disease gene from each parent. Explain why the negative control sample (from an unaffected individual) only produced one band.   b. Explain why the positive control sample (from an individual affected by Huntington’s disease) produced twobands.

W = white (W dominant over w) (WW lethal) (W overrides all other pigments/patterns/colors). G = gray (G dominant over g) (G overrides all other pigments/patterns/colors except for white (W). E = extension red/black (E dominant over e) A = Agouti black restriction (A dominant over a) C = Cremello (C co-dominant with Ccr to dilute) D = Dun (D dominant over d) A bay horse has red and black hairs, with black restricted to points. E: extension locus (E-black (dominant), e-red, EE-black pigment, Ee-black pigment, ee-red pigment (horse is chestnut)) A: Agouti locus (A-restricts black to points on the mane, tail, legs only (dominant), a-no restriction, AA-restriction (horse is bay), Aa-restriction (horse is bay), aa-no restriction (horse is black), if horse is ee (red/chestnut)-there is no black to restrict! Dilution (cream) gene: C or Ccr, CC-no dilution, CCcr-single dilution, CcrCcr-double dilution. Dun gene: D or d, DD or Dd-dun, dd-no dun. Frame Overo: O or N, OO-Lethal White Foal…

Explain how natural selection might be responsible for the PTC taster polymorphism.Why might some populations have a higher frequency of the taster allele than others?

Epistasis refers to the interaction of genes wherein the expression of one gene is dependent on another gene. For example, suppose there are two genes that code for flower color in a plant, where red, WW or Ww, is typically dominant over expression of white, ww, and yellow, YY or Yy, is typically dominant over green, yy. One type of epistasis expresses a pattern where a dominant allele in either gene produces a red phenotype. Classify the F1 flower color ratio that would be produced from the dihybrid cross for each type of epistasis.

Read the following passage carefully about some aspects of genetics involving a certain species of Drosophila and then answer the following questions in parts  The gene for the production of eye colour in this species of fruit fly can be expressed as either normal red-eyes or as brown-eyes. The allele for the normal red eyes is dominant to that of brown, and is transmitted in normal Mendelian fashion. A gene involved with body colour in this species of fruit fly is located on the non-homologous portion of the X chromosome, and has two alleles, grey and yellow, where the grey allele is dominant to yellow. The two genes are NOT linked.   a) Produce a key to clearly show the nature of the alleles associated with the eye colour in this species of Drosophila, and in each case justify your choice of letters and / or style of presentation to best depict the genetics involved.    b) State the type of genetics involved in terms of body colour, justifying your answer with the evidence from…

CANDY GENETICS: A college student studying genetics has hypothesized that Tavorite type of candy is a genetically inherited trait and thus, 75% of people will prefer Hershey's; 10% Twix; 10% Nerds; and 5% Sour Patch Kids. After tabulating his findings, his data is as follows... 720 prefer Hershey's: 98 prefer Twix; 112 prefer Nerds; and 70 prefer Sour Patch Kids. Statistically, you want to know if his data supports his hypothesis (A) State the null hypothesis.

Even if a character show multiple allelism,an individual will only have two allelkes for that character.why?

Which of the following statements about the pedigree shown below is FALSE? 2 II 3 II 2 3 4 The phenotype of individual II-3 is affected. The genotype of individual Il-1 could be Aa or AA. Genotype of individual Il-3 is AA. Genotype of individual Il-2 is aa. 2.

Scale color in dragons is determined by two genes. The W gene is epistatic to the G gene. The W allele is dominant and allows the production of pigment, while w is recessive and blocks pigment formation, resulting in white dragons. When pigment formation is possible, the dominant G allele results in green dragon scales, while the recessive g allele results in black dragon scales. The pigment formation pathway is shown below W (Enzyme 1) G (Enzyme 2) White precursor Black intermediate pigment Green pigment а. What color scales would you expect in each of the following dragons? WwGg Wwgg WWGG wwgg b. If you cross two dragons with WwGg genotype, what is the expected phenotypic ratios of the progeny? c. What kind of epistasis do we observe?