Question

3. In humans, the following three loci are located on the long arm (q) of chromosome 7: mitochondrial malate dehydrogenase isoforms a and b (MDHA, MDHb)" glucuronidase isoforms i and 2 (GUS1, GUS2) histone isoforms + and -(H,H) Their relative map positions are: MDH 35 GUS 45 A female whose mother was homozygous for MDHA, GUS2 and Hand whose father was homozygous for MDHb, GUS1 and H produces a sample of 1000 ova via hormonal treatment Question: Give the expected numbers of the different types of cells that she would produce, based on their genotypes. The possible genotypes are already plugged in (see table below) Hints: Since we are dealing with human genes, we may have variants called isoforms (i.eya and b; 1 and 2; + and - ) instead of wild type and mutant alleles. Because you are given the map locations, you have to work backwards with respect to the previous problem (i.e., estimate the numbers of possible combinations present in the ova population based on the gene map for which, as you noticed, you need to calculate the distances between the genes). Also, recall that in humans, somatic cells are diploid whereas gametes are haploid. Frequencies DCOS: SCOs (MDH and GUS): SCOS (H and GUS): NCOs: Nº of cells Genotype MDHA GUS2 H MDH) GUSHT MDHA GUSI I MDH) GUS2 MDHA GUS2 H MDHD GUSI H MDHA GUSI H MDHL GUS2 H Total 1000 * Remember that small chromosome arms are designated "p" for petit; long arms are called "," for quere. ** These isoforms of malate dehydrogenase are involved in the Krebs cycle; although present in the mitochondria, the gene is encoded in the nucleus. Some glucuronidases are lysosomal enzymes involved in degradation of mucopolysaccharides. *** Please notice that the number of cells undergoing DCOs have to be subtracted from the SCOs since the DOOs are two simultaneous SCOs Recall that in the reverse process, when calculating map distances from frequencies, the DCO had to be added to the SCOS

Answer 1

Answer has been attached below image.

Frequereis Progeny no 30 Dco. To sco (mon and Gus) 77. Solo (Gus and t) 24 270 NW 637. 630

Femde Mona Gur, hit male mong Gustin Mona MDHb suszguss nt n mona Guso nt us, ntga mons bourl ht Мои .. Gus 21 . 45 35 E 30mu En lomu. No. of D. c.o. ( double crossover) no. of ocio include beth wass betnem mona Guse and moncuse and it crossore a Restinec blogere lo X :30 2-03 (31) totas no program a 1000 no of progeny with doush crossok 200x100 =30 . ③ single hroboch between (mona and bus 2 gue is to mo . . - this also include b.coa actual s.co= 10-3= 7). V o progray of this sco. Ixloo ero slo- betuem Gusz andrita Bomu this albo include forging due to O Co. 30-3= 274 Progery due to scos 7x100 a 270

tatar Reumbiment progeny, . SocoEmona / Sosa) +sco (Gusal lat) to cuy y z 2 7+2 7+3 z 37. 630 . Parental was crossove a 160-372 63+7 100 each of Parental - mona Gosent - 3178 mony Gutt n-315 Genotype no o can mona Susant 315 innssover mono Gussa sw . mona Gustin 35 mon, and I mono Gusant s.com bha Gusah 137 Margus 630 35 husia 70 and hit mong Gurint mona Gust nt mono Gusah-