Hardy-Weinberg Equilibrium

a) Address the following Hardy-Weinberg Equilibrium problem. i) A population of iguanas on the Galapagos Islands has 20 individuals with webbed feet and 180 individuals with the dominant trait of non-webbed feet. What are the frequencies of webbed feet and non-webbed feet traits in this population? ii) How is the dominant allele frequency calculated from this population? iii) Calculate the genotype frequencies: p2 -the frequency of the dominant homozygotes; 2pq –the frequency of heterozygotes; and q2 –the frequency of the recessive homozygotes (hint: insert the values calculated for p and q such that p2+2pq+q2=1.0). Explain why p2 and q2 represent the proport... click for more

Mendel and the Gene Idea

1.) In dogs, black (B) is dominant to chestnuts (b), and solid color (S) is dominant to spotted (s). What are the genotypes of the of the parents that would produce a cross with 3/8 black solid, 3/8 black spotted, 1/8 chestnut solid, and 1/8 chestnut spotted puppies? 2.) When hairless hamsters are mated with normal-haired hamsters, about one-half of the offspring are hairless and one-half are normal. When hairless hamsters are crossed with each other, the ratio of normal-haired to hairless is 1:2. How do you account for the results of the first cross? How would you explain the unusual ratio obtained in the second cross? 3.) Two pigs whose tails are exactly 25 cm in length are bred over... click for more

Can you determine the genotypes of the parents of this cross? Determine the genotypes of the three dogs. Explain why the F1 are all red and how the 9:6:1 ratio of the phenotypes in the F2 occurred.

1.) Fur color in rabbits is determined by a single gene locus for which there are four alleles. Four phenotypes are possible: black, Chinchilla (gray color causes by white hairs with black tips), Himalayan (white with black patches on extremities), and white. The black allele (C) is dominant over all other alleles, the Chinchilla allele (C^ch) is dominant over Himalayan (C^h), and the white allele (c) is recessive to all others. a.) A black rabbit is crossed with a Himalayan, and F1 consists of a ratio of 2 black to 2 Chinchilla. Can you determine the genotypes of the parents? b.) A second cross was done between a black rabbit and a Chincilla. The F1 contained a ratio of 2 black to 1 ... click for more

Genetics Problem - Color Blindness

Colorblindness in humans is x-linked recessive trait. Question: One out of every 12 human males has red green colorblindness. How common is it among human females. Can you show me how to determine its prevalence among females as a genetics problem? I believe the answer to this problem is 1/200 females are colorblind. I found the following on the internet: using the information below I determined an approximate incidence to be 1/192. "Red-green color blindness simply means that a person cannot distinguish shades of red and green (usually blue-green). Their visual acuity (ability to see) is normal. There are no serious complications; however, affected individuals may not be consi... click for more

Genetics Problems

1.) In guinea pigs, black (B) is dominant to brown (b), and dolid color (S) is dominant to spotted (s). A heterozygous black, solid-colored pig is mated with a brown, spotted pig. The total offspring for several litters are black solid=16, black spotted=5, brown solid=5, and brown spotted=14. Are these genes linked or unlinked? If they are linked, how many map units are they apart? 2.) A woman is a carrier for a sex-linked lethal gene that causes an embryo with the gene to spontaneously abort. She has nine children. How many of these do you expect to be boys? 3.) A dominant sex-linked gene B produces white bars on black chickens, as seen in the Barred Plymouth Rock breed. A clutch ... click for more