Question

У крупного рогатого скота шотгорнской породы красная масть (ген «R») доминирует над белой (ген «r»). Гетерозисные животные имеют чалую масть. В Шотландии одна шортгорнская корова принесла за один отел 5 телят , в том числе одного бычка красной масти , двух телок чалой и двух телок белой масти. Можете ли вы определить масть и генотип быка и коровы, от которого родились эти телята?

Answer 1

Ген    признак
RR    красная
Rr     шотгорнская
rr      белая
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РЕШЕНИЕ
Р   Rr     x      Rr   родители
G  R  r          R  r
F1   RR       Rr    Rr      rr        телята
      крас      шорт        бел.

Answer 2

Determining the Coat Color and Genotype of the Bull and Cow

To determine the coat color and genotype of the bull and cow, we need to analyze the information provided in the question.

According to the information given, the red coat color (gene "R") is dominant over the white coat color (gene "r") in the Shorthorn breed of cattle. Heterozygous animals have a roan coat color.

Let's break down the information provided:

- One Shorthorn cow gave birth to 5 calves in a single calving event. - The calves include: - One bull with a red coat color. - Two heifers with a roan coat color. - Two heifers with a white coat color.

Based on this information, we can make the following deductions:

1. The bull has a red coat color, which means it must have inherited the dominant red gene "R" from at least one of its parents. 2. The two roan heifers have a roan coat color, which means they must have inherited one red gene "R" and one white gene "r" from their parents. 3. The two white heifers have a white coat color, which means they must have inherited two white genes "r" from both of their parents.

Now, let's determine the possible genotypes of the bull and cow:

1. Bull: - The bull has a red coat color, so it must have at least one red gene "R". - Since the red coat color is dominant, the bull could have either the genotype "RR" or "Rr". - We cannot determine the exact genotype of the bull without additional information.

2. Cow: - The cow gave birth to both red and white calves, which means it must have inherited at least one red gene "R" from one of its parents. - Since the cow gave birth to two white heifers, it must have inherited a white gene "r" from the other parent. - Therefore, the possible genotype of the cow is "Rr".

To summarize:

- The bull's genotype could be either "RR" or "Rr". - The cow's genotype is likely "Rr".

Please note that without additional information about the genotypes of the parents, we cannot determine the exact genotypes of the bull and cow. However, based on the information provided, these are the most likely possibilities.

Note: The information provided in this response is based on the given scenario and the general principles of coat color inheritance in cattle. It is always recommended to consult a qualified veterinarian or geneticist for accurate and specific information regarding individual animals.