The limbic system, which is the area of the brain involved in emotion and memory, includes the:

Hippocampus, amygdala, thalamus and hypothalamus, basal ganglia and cingulate gyrus.
    The thalamus and hypothalamus accommodate changes in emotional responses while the amygdala identifies which emotions is specifically occurring at the given moment, and if a fight or flight response is required.

    The hippocampus assists in recording new memories about past events, but not necessarily storing those memories.
    The basal ganglia primarily forms habits/records muscle memories, allowing the brain to choose between potential actions and remember what actions were beneficial in the past.
    The cingulate gyrus assists in generating associations between sensations and emotions. So a particular smell resulting in happiness or disgust, or pain resulting in anger or pleasure.

I’m not exactly sure what your trying to ask, but if it’s how an organelle is similar to a body system or a part a nucleus is like a in function. but i don’t fully understand what you’re trying to ask

He used pea plants to study the patterns of heredity.