Hypothetical Chromosomes √Every gene has its place,or locus(基因座)，ona chromosome √Genotype(基因型)is the combination of alleles found in an organism √Phenotype(显型)is the visible expression of the genotype -Wild-type(野生型，wt)phenotype is the most common or generally accepted standard -Mutant(突变体)alleles are usually recessive(隐 性的)
Hypothetical Chromosomes ✓ Every gene has its place, or locus (基因座), on a chromosome ✓ Genotype (基因型) is the combination of alleles found in an organism ✓ Phenotype (显型) is the visible expression of the genotype – Wild-type (野生型, wt) phenotype is the most common or generally accepted standard – Mutant (突变体) alleles are usually recessive (隐 性的)
Genetic Recombination and Mapping 遗传重组和遗传图谱 In early experiments genes on separate chromosomes behaved independently √The law of linkage(连锁定律)：Genes on the same chromosome behaved as if they were linked (genetic linkage) √Incomplete linkage? Offspring show new combinations of alleles not seen in the parents when recombination(重组)occurs
Genetic Recombination and Mapping 遗传重组和遗传图谱 ✓ In early experiments genes on separate chromosomes behaved independently ✓ The law of linkage (连锁定律): Genes on the same chromosome behaved as if they were linked (genetic linkage) ✓ Incomplete linkage? ✓ Offspring show new combinations of alleles not seen in the parents when recombination (重组) occurs
Recombination √During meiosis(减数分裂)，gamete formation, crossing over can occur resulting in the exchange of genes between the two homologous chromosomes(同源染色体) The result of the crossing-over event produces a new combination of alleles This process is called recombination m w* m+ W m m w*
Recombination ✓ During meiosis (减数分裂) , gamete formation, crossing over can occur resulting in the exchange of genes between the two homologous chromosomes (同源染色体) ✓ The result of the crossing-over event produces a new combination of alleles ✓ This process is called recombination
Genetic Mapping Morgan proposed that the farther apart two genes are on a chromosome,the more likely they are to recombine If two loci recombine with a frequency of 1%,they are said to be separated by a map distance of one centimorgan(厘摩)(named for Morgan) Relationship between the distance separating two genes on a chromosome and the frequency of recombination between these two genes.->genetic mapping techniques
Genetic Mapping ✓ Morgan proposed that the farther apart two genes are on a chromosome, the more likely they are to recombine ✓ If two loci recombine with a frequency of 1%, they are said to be separated by a map distance of one centimorgan (厘摩) (named for Morgan) ✓ Relationship between the distance separating two genes on a chromosome and the frequency of recombination between these two genes. →genetic mapping techniques
1.2 molecular genetics Nobel medal Half a pound of 23- karal gold. 2.5 inches across What are genes made of?And how does they work?
Nobel medal Half a pound of 23- karal gold. 2.5 inches across 1.2 molecular genetics What are genes made of? And how does they work?