Question
Codominance 14. A black chicken (BB)is crossed with a speckled chicken (BW). a Show the Punnett square for the cross. __ b. What is the predicted genotypic ratio for offspring? c. What are the chances of having a white chick? __
Solution
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Jarvis
Advanced ยท Tutor for 1 years
Answer
a. The Punnett square for the cross is as follows: | B | B | |---|---| B | BB| BB| W | BW| BW|b. The predicted genotypic ratio for offspring is 0 BB : 4 BW : 0 WW, which simplifies to 0:4:0.c. The chances of having a white chick (WW) are 0%.
Explanation
1. Understanding Codominance: Codominance is a form of inheritance where two different alleles for a gene are both expressed in the phenotype. In this case, the alleles are B (black) and W (white).2. Setting Up the Punnett Square: A Punnett square is a diagram used to predict the genotypes of offspring from a cross. The black chicken has the genotype BB, and the speckled chicken has the genotype BW. The Punnett square will have four cells, each representing a possible genotype of the offspring.3. Filling the Punnett Square: - The top row of the square will have the alleles from one parent (BB). - The side column will have the alleles from the other parent (BW). - Each cell is filled by combining one allele from the top and one from the side.4. Determining the Genotypic Ratio: The genotypic ratio is the ratio of different genotypes in the offspring. In this case, we count the number of BB, BW, and WW genotypes.5. Calculating the Chances of a White Chick: White chickens would have the genotype WW. However, since neither parent carries the WW genotype, the probability of having a white chick is 0%.6. Conclusion: The Punnett square will show the possible genotypes of the offspring, and from this, we can determine the genotypic ratio and the probability of obtaining a white chick.