If a dominant disorder is described as being 80% penetrant, what would this mean? O The amount of expression within individuals varies O The disorder is present in 20% of the individuals that have the dominant allele O 20% of the individuals who have the dominant allele may have genes that mitigate (prevent) the disorder and therefore do not display symptoms O The trait is present in 80% of the total population.

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.

Pigment produced in cells which are located at the base of growing hairs is packedinto granules which are then transferred to the growing hair shaft. The gene controllingthis transfer of pigment granules to growing hair has the alternative allelesD : uniform distribution of pigment granules in hair ---- intense colourd : uneven distribution of pigment granules in hair -------dilute colourThe colour of cats homozygous dd, is diluted as shown below non dilute   dilute black dd blue brown dd lavender orange dd cream The colour of cats either DD or Dd is intense, or non-dilute. Note that alternativenames for colours are sometimes used. Seal for black, grey for blue, chocolate forbrown, lilac for lavender and red or yellow for orange. Genetically, there is nodifference between the particular alternatives.Examine poster 4 – cats. a. What is the genotype, with respect to the ‘B’ and ‘D’ loci of blue point kitten, lavender point kitten and brown point kittenb. What is the genotype…

Why are sex-linked traits more common in males than in females? Select one: a. All alleles on the Y chromosome are recessive O b. Genes on the Y chromosome activate recessive genes on the X chromosome O c. Females never express recessive alleles on the X chromosome O d. A recessive allele on the X chromosome will always produce the trait in a male O e. All alleles on the X chromosome are dominant z/attempt.php?attempt=1173673&cmid=3837312&page=6#

Look at your family. Identify 1 dominant and 1 recessive trait apparent in your immediate family. Predict how the identified traits will be expressed in future generations. What is known about genes/alleles that affect these traits?

Brown eyes are dominant over blue eyes. This is NOT a sex linked trait. Cross a brown eyed Color blind male (whose mother had blue eyes) with a normal blue eyed female (whose father was colorblind)

LO 79 Explain that a phenotype might be monogenic at the molecular level, but polygenic at the organismal level. What is true about the phenotypic expression of a gene? Genes can code for mRNA One gene can be responsible for part of an organismal trait One gene can be singly responsible for a organismal trait Genes can be expressed as structural proteins One gene can code for more than one molecule

Traits are are controlled by a single gene, such as corn color, can be used fo predictability of trait in inheritance in humans also. This is especially import for parents who may carry alleles that code for diseases. Parents can predic probabilities that their child might inherit a disease if they know their own genotype. Parents that are carriers (heterozygous) may not show disease, bu can still pass on a disease allele. Read the scenario below (in bold). Using a separate piece of paper and draw out a Punnett square, with required information (questions 1-5). The letter D will be used to represent the domina (healthy) allele. Tom and his wife Julie are both carriers for cystic fibrosis, an autosomal recessive disease. Draw a Punnett square and be sure to include the following information for full credit: 1. Place the parents alleles at the top and on the left side. 2. Write in the allele crosses inside the Punnett squares. 3. Write out the genotypes probabilities for an offspring. 4.…

. The production of pigment in the outer layer of seedsof corn requires each of the three independently assorting genes A, C, and R to be represented by at leastone dominant allele, as specified in Problem 64. Thedominant allele Pr of a fourth independently assortinggene is required to convert the biochemical precursorinto a purple pigment, and its recessive allele pr makesthe pigment red. Plants that do not produce pigmenthave yellow seeds. Consider a cross of a strain of genotype A/A ; C/C ; R/R ; pr/pr with a strain of genotypea/a ; c/c ; r/r ; Pr/Pr.a. What are the phenotypes of the parents?b. What will be the phenotype of the F1?c. What phenotypes, and in what proportions, willappear in the progeny of a selfed F1?d. What progeny proportions do you predict from thetestcross of an F1?

Explain how you would go about determining therelative importance of genes and the environment forvariation in risk for a complex trait such as type 2 diabetes.