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 & Explanation:
The examined tissue could be cortex, due to the fact that it's rigid and does not require oxygen, so metabolic processes, like respiration, are not happening. The cortex, or wood, is dead tissue that no longer develops metabolic processes. It starts growing as the plan also grows, and the cambium tissue is in charge of this process.
The correct answer is option (d) that is dizygotic twins.
The dizygotic twins also known as non-identical twins or fraternal twins, that is, two siblings who come from distinct eggs or ova, which are discharged at the similar time from an ovary and are fertilized by different sperm.
They are liquid lipids..
(d)