I think dr. Powell is a professional in the field of :
Clinical psychology
Clinical psychology is a branch of the field of psychology that focused on treating and diagnosing emotional, mental, and behavioral disorders.
Answer:
The plant populations would be reduced
Explanation:
When it is said that mutation is the ultimate source of genetic variation it means that it creates several new combinations which is similar to meiosis and fertilization because <span> new alleles and genes appear. It is just about some common points.</span>
Adaptive immunity.
When antibodies are produced by lymphocytes, the body is conducting adaptive immunity.
Adaptive immunity is the body's way of identifying the presence of an antigen, recognizing what type of antigen it is, and producing antibodies that are specifically designed to attacked the said antigen.
Genes that are expressed all the time are dominant ones. They can also be seen all the time if it is a genotype(ie. eye color, hair color, etc.)