Why loss of function mutations most lof mutations are

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: recessive. Why? Figure 2. Mendel’ dihybrid and trihybrid crosses. Mendel used these crosses to establish the principle of independent assortment. s Example 1: Loss of function mutation The gene and the chromosome it is on are shown beneath the dominant allele in each cross.These are the only dihybrid and trihybrid crosses that Mendel reported. In both dihybrid crosses, Mendel used genes on different chromosomes; as expected, these genes assorted independently. In the trihybrid cross, Mendel used three genes. One of these, r, is on chromosome 5 and assorts independently of the other traits.The other genes, I and a, are both on chromosome 1 but are located at 110 cM and 40 cM, respectively. Since they are 70 cM apart, there is 70%crossing-over between them, so they assort independently even though they are on the same chromosome. Note:“ y Seed Coat”and“ iolet-red Flowers”refer to the a locus, the same locus as Purple Flowers.This is an example of pleiotropy. Gra V The A allele results in purple (red-violet) flowers and gray seed coat, whereas the a allele results in white flowers and white seed coat. example 1: pheide a oxygenase (PAO) •breaks down chlorophyll in peas as they mature T o i ll u st r at e t h i s, I sh o w m y st u d en ts a p ictu re o f fiv e g en etically sh o r t c ab b ag e p lan ts. G ib b erellin h as b een ad d ed to th e t...
View Full Document

This note was uploaded on 10/16/2013 for the course BBIO 360 taught by Professor Marcservetnick during the Fall '12 term at University of Washington.

Ask a homework question - tutors are online