Answer:
I think the last answer D
Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
Answer:
Recent studies of the veterinary profession have established a need for training in various areas beyond those directed toward building competence and proficiency as a clinician. To address this need, a workshop was designed whose objective was to develop a detailed outline of a model curriculum that would encompass the skills, knowledge, aptitudes, and attitudes deemed essential for economic success in the veterinary profession. The model curriculum was created from comprehensive input provided by consultants and educators. Constraints for implementation of this curriculum are identified, and future directions are discussed.
The answer is the second choice
One natural disaster has the ability to wipe out large crops and buildings that were used to fuel Earth's economy. It can also lead to a lack of biodiversity of an area that experienced the disaster.
For example, a tsunami can destroy buildings and kill an abundance of wildlife.
I hope I helped!