We should expect that the rat will have have more difficulty in learning the task compared to a normal rat. This is because the rat has been injected with a certain drug that oppresses the dopamine activity. And then the rat is placed in an operant chamber where a lever-pressing task is shaped through positive reinforcement.
Answer: Homologous chromosomes are the pairs of chromosomes that having same gene sequence, equal length of arms and centromere location. Homologous chromosomes have two homolog one come from male parent and other come from female parent.
Explanation:
These chromosomes Are formed for the purpose of genetic variations. They are called homologous because when two same structured exist it form pair together