Homeostasis is <span>the body's tendency to maintain relatively stable internal conditions in spite of greater changes in its external environment. It is a process in which all body cells are involved and through which the body systems stays stable and keeps constant internal environment. Homeostasis enables the body to maintain its balance and stability. </span>
Maintaining blood temperature is one of homeostasis example. Mamalia is an animal group called warm-blood because their body temperature is maintained. By keeping the body temperature stable, the enzyme used in the body can work in optimal temperature. That makes them use energy more efficiently.
It is given that the allele B for the black coat is dominant over allele b for a brown coat.
A dominant allele always leads to the expression of the dominant trait in the heterozygous condition.
When a black and brown horse is crossed as given in the question and the result is a brown foal, then the genotype of the brown foal must be bb as the brown coat is a recessive trait.
Since each parent contributes one allele each for a given gene, the black horse must have b allele, and hence must be heterozygous Bb.
