ANSWERS: BI311 Homework Assignment #2<\/p>\n
Chapter 2<\/u><\/p>\n
2.2:\u00a0\u00a0 2\/3. Because the seed is round it cannot be ww. Ww seeds give 2 bands in the gel. Of the round seeds, 1\/3 are WW and 2\/3 are Ww.<\/p>\n
2.4. \u00a0\u00a0 Note that you assume \u2018rare\u2019 alleles to exist in heterozygous state.<\/p>\n
a) parents must be Aa x aa <\/em>so the risk of having an Aa<\/em> child is 1\/2<\/p>\n b) parents must be Aa<\/em> x Aa<\/em> so the risk of having an aa<\/em> child is 1\/4<\/p>\n c) parents must be Aa <\/em>x aa<\/em> so the risk of having an aa <\/em>child is 1\/2<\/p>\n <\/p>\n 2.8.<\/p>\n a) Individual II-2 is aa<\/em><\/p>\n b) Both individuals I-1 and I-2 must be Aa<\/em><\/p>\n c) Individuals II-1 and II-3 are either AA <\/em>or Aa<\/em><\/p>\n d) Because II-3 is phenotypically normal, the odds that they are heterozygous\u00a0carrier is 2\/3<\/p>\n <\/p>\n 2.16:\u00a0\u00a0 Due to Mendelian segregation, the expected numbers are: a) 0; b) 100; c) 200; d) 100; e) 0; f) 0<\/p>\n <\/p>\n 2.21.<\/p>\n a) Recessive allele because the affected individual had unaffected parents. Also, the\u00a0parents of the affected individual are related.<\/p>\n b) The double line indicates a mating between relatives.<\/p>\n c) III-1 and III-2 are first cousins.<\/p>\n d) I-1 and I-2 could be (AA<\/em>) or (Aa<\/em>). At least one individual must be (Aa<\/em>) or both\u00a0could be (Aa<\/em>). Not possible for both to be (AA<\/em>).\u00a0II-1 and II-4 are most likely (AA<\/em>) because they a<\/em> allele is a rare trait. Individuals that\u00a0marry into a family are assumed to be wildtype unless there is evidence to the\u00a0contrary. \u00a0\u00a0III-1 and III-2 are both (Aa<\/em>) because they have an affected offspring (IV-4).<\/p>\n \u00a0<\/u><\/p>\n Chapter 3<\/u><\/p>\n 3.1. After the centromeres have split, each former sister chromatid is counted as a chromosome in its own right, so at anaphase there are 92 chromosomes.<\/p>\n <\/p>\n Additional Questions not in your textbook:<\/u><\/p>\n #1<\/strong>. On the basis of Mendel\u2019s observations, predict the results from the following crosses with peas:<\/p>\n a) true-breeding tall peas x true-breeding dwarf peas<\/p>\n all tall<\/p>\n b) the offspring of (a) self-fertilized<\/p>\n \u00be tall, \u00bc dwarf<\/p>\n c) offspring of (a) crossed with the original tall parent<\/p>\n all tall<\/p>\n d) the offspring of (a) crossed with original dwarf parent<\/p>\n \u00bd tall, \u00bd dwarf<\/p>\n <\/p>\n #2.<\/strong> In pigeons, a dominant allele C<\/em> causes a checkered pattern in feathers, the recessive allele c<\/em> produces a plain pattern. Feather color is controlled by an independently assorting gene; where the dominant B<\/em> allele causes red feathers and the recessive allele b<\/em> produces brown feathers. You cross a true-breeding checkered red pigeon with a true-breeding plain brown pigeon.<\/p>\n a) What is the phenotype<\/u> of the F1 offspring?<\/p>\n checkered and red feathers<\/p>\n b) If these F1 offspring are crossed with each other, what phenotypes<\/u> will appear in the F2 generation, and in what proportions?<\/p>\n 9 checkered red : 3 checkered brown : 3 plain red : 1 plain brown<\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" ANSWERS: BI311 Homework Assignment #2 Chapter 2 2.2:\u00a0\u00a0 2\/3. Because the seed is round it cannot be ww. Ww seeds give 2 bands in the gel. Of the round seeds, 1\/3 are WW and 2\/3 are Ww. 2.4. \u00a0\u00a0 Note that you assume \u2018rare\u2019 alleles to exist in heterozygous state. a) parents must be Aa … <\/p>\n