Reading Comprehension

PT112 · S2 · P3 · Q15 Hormones

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Discussions of how hormones influence behavior have generally been limited to the effects of gonadal hormones on reproductive behavior and have emphasized the parsimonious arrangement whereby the same hormones involved in the biology of reproduction also influence sexual behavior.

Topic

Hormones and their role in both reproductive and homeostatic (fluid balance) behaviors

Framework

Old / New

Main Point

Previously, people mainly focused on how reproductive hormones affect sexual behavior, but now it’s clear that other hormones, specifically those involved in fluid balance (like vasopressin), also play an important role in controlling behaviors such as water and salt consumption. ( — middle of P1)

P1: Challenging the Narrow Focus on Hormones

Most research has looked at how reproductive (gonadal) hormones affect sexual behavior, but now scientists realize that hormones involved in regulating body fluids (homeostasis) also influence behavior, like thirst and salt appetite. Homeostasis keeps plasma osmolality (solute concentration) steady by tweaking water and sodium intake and output whenever even small changes arise.

P2: How Homeostatic Hormones Control Thirst and Water/Salt Balance

This paragraph explains how water and solute levels are managed in the body through both physiological and behavioral responses. For example, if you have too much water in your body, the hormone vasopressin gets suppressed so your body can get rid of the excess through urine and you stop feeling thirsty. If your blood is too salty, vasopressin gets released to conserve water and increase thirst, so you’ll drink more and dilute the salts. Thirst kicks in only after the body’s initial physiological measures (like vasopressin release) have already tried to fix the imbalance.

15.

Which one of the following best states the main idea of the passage?

  1. Both the solute concentration and

    Too Narrow: solute concentration

    There's no reason we should be seeing "blood plasma" or "solute concentration" in the main point. The central topic is "hormones influencing human behavior", with a focus on "peptide / steroid hormones influencing the behavior of water/salt consumption". This answer doesn't mention any of that. This answer is establishing that animals want homeostasis, but it doesn't touch on how hormones influence human behavior.

    1% picked this

  2. Behavioral responses to changes in

    Too Narrow: avoiding dehydration

    There's no reason we should be seeing "blood plasma" or "dehydration" in the main point. The central topic is "hormones influencing human behavior", with a focus on "peptide / steroid hormones influencing the behavior of water/salt consumption". This answer doesn't mention any of that. This is saying that behavior changes in response to a change in blood plasma, without ever mentioning that the change in blood plasma causes a hormone (the central topic) to be released, which then affects behavioral responses. This answer also makes the idea of "avoiding dehydration" seem like it was important, but the author is focused on how we avoid both dehydration and over-hydration.

    4% picked this

  3. The effect of hormones on

    Too Strong: only recently discovered

    It has only recently become clear that hormones in addition to gonadal ones have an influence on human behavior. This is saying we've only recently discovered the effect of hormones on animal behavior, but we've long known about the effect of gonadal hormones on sexual behavior.

    5% picked this

  4. Correct

    Behavioral and physiological responses to

    Why this is right

    This is a surprisingly specific and narrow version of the main point, but we're always forced to find the best available. Rather than capturing any of the framing ideas that "we used to only think gonadal hormones influenced behavior, but now its clear that other hormones also influence behavior", this answer zooms in on the details of the New finding. It doesn't talk about the Theme, just about the Example. This is the only answer that includes the idea of "hormones influencing behavior", which was the central topic. It's saying that when the osmolality of our blood plasma starts to stray from its desired level, we have behavioral and physiological responses that are affected by hormones and complement each other.

    Skill tested: Main Point · how this choice captures the passage's function is the move to repeat next time.

    85% picked this

  5. The mechanisms regulating reproduction are

    Too Strong: similar mechanisms

    If by "similar mechanisms" we mean "hormones", then we could say that hormones both affect reproduction and affect thirst and sodium appetite. It's too strong to say that hormones regulate reproduction. We only know they are involved in the biology of reproduction. And the hormones that influence reproduction are gonadal hormones. The hormones that influence thirst and sodium appetite are peptide and steroid hormones. Are those similar mechanisms? It's hard to say whether those are close enough to call similar mechanisms. Overall, the verb "regulated" is only used in relation to osmolality of blood plasma. When we talk about reproduction or thirst/sodium appetite, we're talking about hormones influencing behavior.

    5% picked this

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