BIOS 10161 Lecture Notes - Lecture 28: Dihybrid Cross, Punnett Square, Allopatric Speciation

• School: ND
• Department: Biological Sciences
• Course: BIOS 10161
• Professor: Schulz, Robert

Document Summary

In f2 generation, predict some have same dominant phenotype, but different genotype: test crosses determines whether an individual is homozygous of heterozygous for a trait by crossing it with the homozygous recessive. Mendel crossed the f2 with known homozygotes. Me(cid:374)del"s (cid:374)e(cid:454)t e(cid:454)peri(cid:373)e(cid:374)t: crossing peas that differed in two characters seed shape and seed color, true breeding plants. If linked: gametes would be sy or sy. F2 would have 3x more spherical yellow than wrinkled green. If independent: gametes could be sy, sy, sy, or sy. Results in new combinations called recombinant proteins. Me(cid:374)del"s seco(cid:374)d law: the law of i(cid:374)depe(cid:374)de(cid:374)t assort(cid:373)e(cid:374)t: (cid:862)i(cid:374) the for(cid:373)atio(cid:374) of ga(cid:373)etes, the segregatio(cid:374) of alleles of two ge(cid:374)es is i(cid:374)depe(cid:374)de(cid:374)t(cid:863, does(cid:374)"t al(cid:449)a(cid:455)s appl(cid:455) to ge(cid:374)es o(cid:374) the sa(cid:373)e (cid:272)hro(cid:373)oso(cid:373)e, (cid:271)ut (cid:272)hro(cid:373)oso(cid:373)es do segregate independently. Probability =1: event cannot possibly happen. Probability = 0: all other events.