in cattle a dominant gene (N) results in a deep notch in each ear. a recessive gene (n) results in an "udder" abnormiality when in the homozygous condition. a farmer desires to rid his herd of these characteristics. which of these two alleles would be easiest to eliminate from his herd. explain how the farmer would eliminate this allele.
I don't understand why the same letter is being used for two different characteristics.
The only thing I can think of is that nn results in the udder abnormality and Nn gives an ear notch. This doesn't sound too logical, so it might be a typo.
The use of the same letter for two different characteristics can be a bit confusing. Let's assign different letters to avoid confusion. Let's use "N" for the dominant gene resulting in a deep notch in each ear, and let's use "U" for the recessive gene resulting in the "udder" abnormality.
To determine which of these two alleles would be easiest to eliminate from the herd, we need to consider their inheritance patterns. The dominant gene (N) will be expressed even if there is only one copy of the allele present. On the other hand, the recessive gene (U) will only be expressed when an individual has two copies of the allele (homozygous condition).
In this case, the recessive allele (U) would be easier to eliminate from the herd. Here's how the farmer could eliminate this allele:
1. Identify individuals with the "udder" abnormality: The farmer needs to identify which animals in the herd exhibit the "udder" abnormality. This can be done by visual inspection or by conducting genetic tests.
2. Remove individuals with the "udder" abnormality from the breeding program: Once the animals with the "udder" abnormality have been identified, the farmer should not use these animals for breeding purposes. By not breeding animals carrying the recessive allele (U), the chances of passing on this abnormality to the next generation will significantly decrease.
3. Select mating pairs without the recessive allele: The farmer should select mating pairs that do not carry the recessive allele (U). By breeding animals only from the "Nn" or "NN" genotypes, the offspring will not inherit the recessive allele (U). This selection process should continue throughout multiple generations to progressively decrease the frequency of the recessive allele (U) in the herd.
4. Regular monitoring and selection: The farmer should regularly monitor the offspring and select individuals without the recessive allele (U) for future breeding. By consistently following this method of selection, the frequency of the recessive allele (U) will gradually decrease over time, eventually leading to its elimination from the herd.
It's worth noting that eliminating a recessive allele completely from a population can be a long and gradual process requiring careful breeding practices and continuous monitoring.