Yeah, they gave Maureen a serious case of the stupids for that and John said, kind of "not exactly," and then launched into an explanation that show it was nothing like blood plasma. Then, like a simpleton, Maureen smiled and said, "I see." Prompting John to say, "no you don't." It's really a hilarious scene. Unintentionally, no doubt.
It looks bad now, but women of the period, the majority, were not that into mechanics and science. Rosie the Riveter was sent home after the war. For every Amelia Earhart or Hedy Lamarr, there were a million and a half homemakers whose big brush with technology was the electric mixing bowl.
Actually it's not quite as bad as all that. Maureen Robinson was established in the pilot as a doctor of biochemistry. She was a scientist in her own right, she just wasn't an expert in physics or engineering. So her ignorance in that scene is plausible because it wasn't her field of study (and it's consistent that she'd ask about blood plasma, which is in her field). Granted, her doctorate was only mentioned once after the pilot, but it was an established part of her background.