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Genetic mapping from three point cross (in Hindi)
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Three point cross and related questions

Manisha Malhotra
Msc in microbiology with gold medal, qualified GATE and Uttarakhand-set. Admin of the you tube channel Manisha Malhotra tutorials.

U
Unacademy user
gene order is d w c and recombination frequency b/t d and w is 9.8cM and w and c is 31.4cM
mam plz give the explanation of last question
Manisha Malhotra
4 months ago
Pls watch other course I have already provided with the solution there
31.4- recombination frequency b/w ct and w 10.4- recombination frequency b/w w and dy
Manisha Malhotra
7 months ago
What would be the gene order?
Manisha Malhotra
7 months ago
I will provide u all with the solutions in my next course...
Manisha Malhotra
7 months ago
Try again and see whether 31.4 is between w and c or d and w...and 10.4 will not be any ans
Pakala haripriya
7 months ago
OK mam
Priti Niranjan
7 months ago
Gene order will be dwc
Pratibha sharma
4 months ago
gene order is dwc and recombination frequency between d and w is 9.8cM and between w and c is 31.4cM
PG
mam please discuss the solution of that question i m not able to solve that plz
Manisha Malhotra
7 months ago
U will get all the solutions in my next course so stay tune😊
how to determine which is single or double cross?
  1. Gene mapping from three point cross


  2. Three point cross involves three gene loci. It is used to determine gene order and distance between three genes. From three point cross different recombinant products are obtained because of single and double crossing over between the genes.


  3. Single crossing over between R and S Single crossing over between S and T Double crossing over R S T R ST R ST r S


  4. Que- In Drosophila, Bar eye(B) is a dominant mutation while miniature wing(m) and yellow body color (y) are recessive mutations. Heterozygous females for these mutations were crossed to normal eyed miniature winged and yellow body colored males. Based on the results obtained determine the gene order and distance between the genes.


  5. Number Phenotype 40 30 175 130 25 195 120 B+ m+ y Bm+ y B m y B m y


  6. Parental type B m+ yB m y Double crossover Bm+ y Gene order B y m


  7. Single crossing over between B and y Single crossing over between y and m Parent B y+ m+ B y+m Parent 2 Bt y m B+ y m B y m y+ m B+ y+ m+ B+ y m+


  8. Phenotype Bytm+ Bt y m Bt y m+ B yt m By m Number Crossover 195 175 130 120 Parental type Parental type Single crossover between y and m Single crossover between y and m Single crossover between B and y Single crossover between B and y Double crossover Double crossover 40 30 25 By m By m+


  9. No. of single crossing over No. of double crossing over Recombinant frequency between genes Total number of offsprings (55+40) (25+30) Recombinant frequency between B and y 100 195+175+130+120+55 40+30+25 - (95) +(55) Recombinant frequency between B and y 100 770 150 10019.48CM 770


  10. No. of single crossing over No. of double crossing over Recombinant frequency between genes Total number of offsprings (120+130) + (25+30) Recombinant frequency between B and y 100 195+175+130+120+55 40+30+25 (250) +(55) Recombinant frequency between B and y 100 770 305 10039.61cM 770


  11. Genotype Number observed Wild type(++t) Dusky body(d++) Cut wings(tct) White eyes(+tw) Dusky body, cut wings(d,c+) Dusky body, cut wings, white eyes(d,c,w) 22 18 153 6 76 72 Dusky body, white eyes(dtw) Cut wings, white eyes(+cw) 3 150