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- Dihybrid inheritance
- lots of genes inherited, and dihybrid crosses show inheritance of 2 genes on diff chromosomes
- Dihybrid cross
- shows inheritance of 2 diff characteristics caused by 2 genes, so 4 alleles shown at each stage (2 for each characteristic)
- e.g pea plants yellow(Y)/green(y) and round(R)/wrinkled(r)
- genotype, watch out for homo/heterozygous, e.g homo yellow round seeds genotype is YYRR, but hetero yellow round seeds is YyRr, homo green wrinkled seeds is yyrr
- with the homo, gametes combos are just YY and RR, or yy and rr, but hetero (YyRr) gametes are the 4 diff combos (YR,Yr,yR,yr), so use all 4 lined up at top/side of cross against the other genotype (2 hetero genotypes result in 9;3;3;1 ratio
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