Two purple flowers (Bb) are bred with each other in the same garden. What are the odds that red (BB) and blue (bb) flowers will occur in the second generation?
A. 50% red flowers; 50% blue flowers
B. 25% red flowers; 75% blue flowers
C. 75% red flowers; 25% blue flowers
D. 25% red flowers; 25% blue flowers
I'm thinking it's either A or C. Please help? Thanks
Oh, it was D. 25%; 25% .....
B b
B BB Bb
b Bb bb
You see your possibilities. Now, can you get your percents?
To determine the probabilities of red and blue flowers occurring in the second generation, we need to understand the concept of genetic inheritance and the Punnett square.
In this scenario, we have two purple flowers (Bb) being bred with each other. The color purple is the result of having one dominant allele (B) for blue and one recessive allele (b) for red.
When we breed two purple flowers (Bb x Bb), we can use a Punnett square to visualize the possible combinations of alleles that the offspring can inherit.
| B | b |
--------------------
B | BB | Bb |
--------------------
b | Bb | bb |
In the Punnett square above, the letters on the top represent the alleles from one parent, and the letters on the side represent the alleles from the other parent. The letters inside the table represent the possible genotypes (BB, Bb, bb) that can result from the combination of alleles.
The genotypes BB and bb represent red and blue flowers, respectively. The genotype Bb represents purple flowers.
Looking at the Punnett square, we can see that there are three possible genotypes in the second generation: BB, Bb, and bb. The probability of each genotype occurring depends on the combination of alleles.
There are four possible combinations in total:
1. BB (red flowers): This combination can only occur if both parents contribute the dominant B allele. The probability of getting BB is 1/4 or 25%.
2. Bb (purple flowers): This combination can occur if one parent contributes the dominant B allele and the other contributes the recessive b allele. The probability of getting Bb is 2/4 or 50%.
3. bb (blue flowers): This combination can only occur if both parents contribute the recessive b allele. The probability of getting bb is 1/4 or 25%.
From the above analysis, we can conclude that the second generation will have a 25% chance of red flowers (BB) and a 50% chance of blue flowers (bb). The correct answer is:
B. 25% red flowers; 75% blue flowers