Biology 240, Quiz – 3 (Wk of Sept 14). Total points = 10 (with key)Name____________________________ I.D#________________Section#___________Q 1. In pea plants, T, R and Y alleles are dominant to t, r and y alleles, respectively, and these allele pairs assort independently. When a TtRrYy was selfed, 1600 offspring were produced. How many of them were TTRrYy?a) 400?b) 100?c) 900?d) 300?Q 2. In Drosophila, Cy is a dominant autosomal mutation that gives curly wings. The wild type allele cy is recessive and it gives straight wings. Cy is also a recessive lethal allele. If a curly female is crossed to a curly male, which of the following results would you expect in the F1 flies?a) 3/4 curly, 1/4 straight.b) 50% curly, 50% straight.c) 100% curly.d) 2/3 curly, 1/3 straight.Q 3. In humans, inability to taste (non-taster) PTC isan autosomal trait and recessive to ability to taste (taster). If a heterozygous man marries a heterozygous woman, what is the chance that their first child will be a non-taster boy?a) ¼.b) 3/8.c) 1/8.d) ½Q 4. In four-o’-clock plants, c+/c+ produces red flowers and c/c produces white flowers. Due toincomplete dominance, heterozygote plants produce pink flowers. If a pink-flower plant is crossed to a white-flower plant, which of the following results would you expect in the offspring?a) ¾ will have pink flowers.b) ¾ will have red flowers.c) 50% will have pink flowers.d) 50% will have red flowers.Q 5. A pea plant is heterozygous for three pairs of independently assorting alleles. If this plant is selfed, which of the following results are expected in the F1plants? a) Eight different genotypes.b) Twenty seven different genotypes.c) Nine different genotypes.d) Four different phenotypes.e) Twenty-seven different phenotypes.Q 6. The trait shown in the pedigree below is most likely:a) Autosomal and recessive. b) X-linked and dominant. c) Autosomal and dominant.d) Y-linkede) X-linked dominant.Q 7. In the mouse, gene A allows pigmentation to be deposited in the individual coat hairs; its allele a prevents such deposition of pigment, resulting in an albino. Gene B gives agouti (wild-type fur); its allele b gives black fur. Suppose a cross between 40 doubly heterozygous male and 40 doubly heterozygous female mice in a colony produced 160 progeny of different phenotypes. Write name and number (how many) of each phenotype expected in the progeny. You need to show how you determined the number. 2 + 2 = 4 ptsAnswerA/ - , B/ - = ¾ x ¾ x 160 = 90 = agoutia/a , B/- = ¼ x ¾ x 160 = 30 = albinoA/ -, b/b = ¾ x ¼ x 160 = 30 = blacka/a; b/b = ¼ x ¼ x 160 = 10 = albinoagouti = 90; albino = 40; black =
View Full Document