Practice pop gene questions 2021 ANSC 313 PDF

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Population Genetics Questions part 2...

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Practice pop gene questions 2021 ANSC 313 C Problems – please use pen and show your workings. Round q and p to two decimal places. 1) You breed Shorthorn cattle where 15% are white. Currently roan (Rr) bulls bring the best prices so you left those intact for sales and castrated 30% of the red (RR) and all the white (rr). What is the gene frequency of white in their calves. (10 marks)

2) Dwarfism in some breeds of beef cattle has recently been shown to be caused by mutations in the limbin gene. Approximately 16% of one cattle breed has recessive dwarfism. A rancher has purchased a herd of normal height cattle of this breed. What proportion of the calves born on this ranch will be dwarf? (8 marks)

3) Abnormally curly hair has been observed in 8% of a population of Ayrshire cattle. The trait is inherited as an autosomal dominant in Ayrshires. What are the expected frequencies of the “curly” and “noncurly” alleles in this population if the it is in equilibrium. (5 marks)

3) Hairlessness in Herefords is inherited as an autosomal recessive trait (h/h). Although relatively rare overall, it occurred in 9% of the calves born on a large Hereford ranch last year. A new DNA test has been developed in Illinois and therefore bulls are beginning to be advertised that do not carry this allele. If this ranch breeds retained cows and heifers only to such newly purchased pretested bulls, what will the incidence of the “h” allele be in the calf crop? (10 marks)

4) Holstein cattle have all been horned traditionally, a recessive trait. A few polled mutant Holsteins occurred in Germany were retained and these polled bulls are now in high demand in Europe because dehorning must be done under anesthetic. If your uncle in Holland is planning to breed his traditional Holstein cows with semen from these new heterozygous polled bulls from Germany, how many of his calves will be polled after 3 generations? (12 marks)...