Those organisms are fit which has the ability to survive in harsh climatic condition and transfer their traits to the next generation through the process of reproduction.
Explanation: Fit means they are strong and compete with other organisms for food, shelter and other survival items. Those organisms which are not fit could not survive in harsh environmental conditions and removed from that ecosystem.
Different vegetation has several unique characteristics. A hot dry climatic condition is mostly found in desert areas. Desert has few or no precipitation or rainfall.
Desert soil is also sandy or rocky, more reason why it is so important to find plants that can survive under such conditions and also help against soil erosion. Plants with long roots such as cactuses are preferred in this region.
Warm because land gains heat faster than water when heated by the sun. The heated land then transfers the heat to the atmosphere. The air mass is dry becasue a continent is mainly land and very little water (unlike oceans). There is, therefore, very little moisture in the continental tropical air mass.
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.
