The Following Coat Colors Are Known to Be Determined by Alleles

question 61

Essay

The following coat colors are known to be determined by alleles at one locus in horses:
palomino = golden coat with lighter mane and tail
cremello = almost white
chestnut = brown
The following table gives ratios obtained in matings of the above varieties:
$\begin{array}{lll} \text { Cross } & \text { Parents } & \text { Offspring } \\\hline\\1 & \text { cremello } \times \text { cremello } & \text { all cremello } \\2 & \text { chestnut } \times \text { chestnut } & \text { all chestnut } \\3 & \text { cremello } \times \text { chestnut } & \text { all palomino } \\4 & \text { palomino } \times \text { palomino } & 1 / 4=\text { chestnut } \\& & 1 / 2=\text { palomino }\end{array}$ a) Assign gene symbols for the genetic control of coat color on the basis of these data.
b) Diagram the last two matings.

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Definitions:

Prolonged Vomiting

A condition of continuous or recurrent emesis over an extended period, which may lead to dehydration and electrolyte imbalances.

Stomach Contents

The mixture of ingested food, digestive enzymes, and acids found within the stomach.

Osmolarity

A measure of solute concentration per liter of solution, often used in the context of biological fluids.

ADH Secretion

The release of antidiuretic hormone from the pituitary gland, which helps regulate water balance in the body.