The narrow-sense heritability of wing length in a population of Drosophila melanogaster is 0.8. The narrow-sense heritability of head width in the same population is 0.9. The genetic correlation between wing length and head width is −0.86. If a geneticist selects for increased wing length in these flies, what will happen to head width?

In Drosophila, the allele for long legs (sl*) is wild-type and the allele for short legs (sl) is mutant. The allele for gray body color (b*) is wild-type and the allele for black body color (b') is mutant. The loci for leg length and body color are linked. Flies with sl*sl* b*b* genotypes are mated with flies that have sl s bb genotypes. A testcross was then performed in which the F, offspring with sl*sl b*b genotypes were mated with flies with sl sl. b'b genotypes. The phenotypes of 1000 offspring were recorded. There were 470 flies with long legs and grey body, 30 flies with long legs and black body, 30 flies with short legs and grey body, and 470 flies with short legs and black body. Which of these phenotypes are parental phenotypes? VWhich of these phenotypes are recombinant phenotypes? What is the distance between these two gene loci in centiMorgans (map units)?

QTL mapping and GWA (association) mapping are two different methods used to identify genes that affect complex traits. For each of the following statements, choosewhether it applies to QTL mapping, association mapping, or both.whether it applies to QTL mapping, association mapping, or both.

1. Consider this graph on running speed in huskies Midosspring running speed (m/s) 16 14 12 10 8 + 2 Husky running speed 4 6 8 Midparent running speed (m/s) 10 12 14 16 a. Approximately what is the heritability of running speed in this kennel of huskies? (You can approximate by eyeballing from the graph, no need to calculate the actual slope) b. If the breeder where to selectively breed the dogs, will the dogs run substantially faster in the next generation? c. What else can the breeder do to increase running speed?

In Drosophila melanogaster, wing shape is an autosomal trait. Vestigal wing is recessive (v) to the dominant trait for the normal long wings (V). In a mainland source population, the allele frequency of v is 0.02 . A small, experimental population of 100 flies was introduced on an island and had 20 flies with vestigal wings and 40 heterozygotes. What are the allele frequencies of V and v in this introduced population? What proportion (%) of heterozygotes and homozygous recessive flies would you expect to see after a few generations of mating on this island? What phenomenon of population genetics does this experiment demonstrate? p+q=1, p^2+ 2pq + q^2 = 1

Show all work

in a randomly mating laboratory population of Drosophila, 4% of the flies have black bodies, and 96% have brown bodies. Flies with brown bodies always have at least one parent with a brown body. What is the frequency of heterozygotes in this population?     0.04     0.16     0.08     0.32   The period gene of Drosophila melanogaster encodes for a stretch of Thr-Gly repeated in tandem. In natural populations, the three most common alleles encode for 17, 20 and 23 Thr-Gly repeats.  The amplification by PCR of the allele encoding for 20 Thr-Gly repeats produces a fragment of 320 bp. Using the same set of primers, what is the size expected when amplifying the 17 Thr-Gly allele?     317     303     314     302       in a certain species of plant loci A, B and C have an additive effect on the colour of the flower. Alleles A, B, and C are dominant and alleles a, b and c are recessive.  Knowing that a plant with genotype AAbbCc has a…

A presumed dihybrid in Drosophila, BbFf is testcrossed with bbff. (B-black body, b-brown body, F-forked bristles, f-unforked bristles) The results for the testcross are below: Black, forked: 230  Black, unforked: 210 Brown, forked: 240 Brown, unforked: 250 Determine the expected values and ratios for each genotype.