F13 lecture 2 v2

Many marine invertebrates mate by broadcas7ng gametes

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: return to this concept for popula7ons, HW equilibrium) e.g. cross between two Aa heterozygotes AA, Aa, aa EGGS 50% A 50% a AA, Aa, aa Reginald Crundall Punnett (1875-1967) 50% A 25% Aa 50% a SPERM 25% AA 25% Aa 25% aa Ra5o of genotypes in progeny: 1 : 2 : 1 AA : Aa : aa Punnett could be played by Will Patton Punne= square http://s3.amazonaws.com/criterionproduction/images/2177ae0a97b2ab10cff8e133dc5627339513/2_P riests_large.jpg What about phenotypic ra5os e.g. cross between two Da heterozygotes in Peas (dihybrid cross); D is dominant to d; DD = tall; Dd = tall; dd = short EGGS DD, Dd, dd 50% D 50% d DD, Dd, dd 50% D 25% Dd 50% d SPERM 25% DD 25% Dd 25% dd Punne= square Ra5o of genotypes in progeny: 1 : 2 : 1 DD: Dd : dd tall plants (DD, Dd) short plants (dd) Ratio of phenotypes: 3 tall : 1 short When to use a Punnet square •  When there is random ma7ng –  Gametes are uni7ng to form zygotes at random, with respect to the gene under considera7on •  Many marine invertebrates mate by broadcas7ng gametes, which unite to form zygotes in the water –  Zygote...
View Full Document

This document was uploaded on 02/27/2014.

Ask a homework question - tutors are online