Feedback Loop In Biology Quiz

1. Another example of feedback is seen in childbirth, where stretching of the uterus triggers the secretion of a hormone , oxytocin, which stimulates uterine contractions and speeds up labor.

This is a positive feedback loop

This is a negative feedback loop

This is not a feedback loop

This is a positive feedback loop because the stretching of the uterus triggers the secretion of oxytocin, which in turn stimulates uterine contractions. These contractions further stretch the uterus, leading to more secretion of oxytocin and stronger contractions. This cycle continues until the baby is delivered. In a positive feedback loop, the response amplifies the initial stimulus, leading to a self-reinforcing cycle.

Explanation

This is a positive feedback loop because the stretching of the uterus triggers the secretion of oxytocin, which in turn stimulates uterine contractions. These contractions further stretch the uterus, leading to more secretion of oxytocin and stronger contractions. This cycle continues until the baby is delivered. In a positive feedback loop, the response amplifies the initial stimulus, leading to a self-reinforcing cycle.

2. The body senses that levels of substance C is high in the bloodstream. The brain sends a signal to organ D that causes it to make less substance C until the level of substance C is within normal limits.

This is a positive feedback loop

This is a negative feedback loop

This is not a feedback loop

In this scenario, the body is sensing that levels of substance C are high in the bloodstream. The brain then sends a signal to organ D, instructing it to produce less substance C until the levels return to normal. This process is an example of a negative feedback loop because it acts to counteract the initial change and bring the levels of substance C back within normal limits.

Explanation

In this scenario, the body is sensing that levels of substance C are high in the bloodstream. The brain then sends a signal to organ D, instructing it to produce less substance C until the levels return to normal. This process is an example of a negative feedback loop because it acts to counteract the initial change and bring the levels of substance C back within normal limits.

3. The body senses that there is too much substance X in the blood. The brain sends a message to organ Y to metabolize substance X. The brain keeps sending this signal until the levels of substance X is within normal limits.

This is a positive feedback loop

This is a negative feedback loop

This is not a feedback loop

In this scenario, the body is sensing that there is an excess of substance X in the blood. The brain responds by sending a message to organ Y to metabolize substance X. This action continues until the levels of substance X return to normal. This process is an example of a negative feedback loop because the response from the brain (signaling organ Y) acts to counteract the initial stimulus (excess of substance X). The goal is to restore the balance and maintain homeostasis within the body.

Explanation

In this scenario, the body is sensing that there is an excess of substance X in the blood. The brain responds by sending a message to organ Y to metabolize substance X. This action continues until the levels of substance X return to normal. This process is an example of a negative feedback loop because the response from the brain (signaling organ Y) acts to counteract the initial stimulus (excess of substance X). The goal is to restore the balance and maintain homeostasis within the body.

4. The body senses that substance A is low in the bloodstream. The brain sends a signal to organ B that causes it to make more hormone A until the level of A is within normal limits.

This is a positive feedback loop

This is a negative feedback loop

This is not a feedback loop

In a negative feedback loop, the body senses a deviation from the normal range and activates mechanisms to counteract that deviation and restore the system back to its normal state. In this scenario, the body senses that substance A is low in the bloodstream and the brain sends a signal to organ B to produce more hormone A until the level of A is within normal limits. This is an example of a negative feedback loop because the body is working to restore and maintain homeostasis by reversing the initial deviation from normal.

Explanation

In a negative feedback loop, the body senses a deviation from the normal range and activates mechanisms to counteract that deviation and restore the system back to its normal state. In this scenario, the body senses that substance A is low in the bloodstream and the brain sends a signal to organ B to produce more hormone A until the level of A is within normal limits. This is an example of a negative feedback loop because the body is working to restore and maintain homeostasis by reversing the initial deviation from normal.

5. Feedback is seen in protein digestion, where the presence of partially digested protein in the stomach triggers the secretion of hydrochloric acid and pepsin, the enzyme that digests protein. Pepsin digests proteins, casing more HCl and pepsin to be released.

This is a positive feedback loop

This is a negative feedback loop

This is not a feedback loop

This is a positive feedback loop because the presence of partially digested protein in the stomach triggers the secretion of hydrochloric acid and pepsin, which in turn leads to more digestion of proteins and the release of more HCl and pepsin. This creates a self-amplifying cycle where the initial stimulus (partially digested protein) leads to an increase in the response (secretion of HCl and pepsin), which further enhances the initial stimulus.

Explanation

This is a positive feedback loop because the presence of partially digested protein in the stomach triggers the secretion of hydrochloric acid and pepsin, which in turn leads to more digestion of proteins and the release of more HCl and pepsin. This creates a self-amplifying cycle where the initial stimulus (partially digested protein) leads to an increase in the response (secretion of HCl and pepsin), which further enhances the initial stimulus.

6. The kidneys sense that the oxygen levels in the blood are low. The kidney sends a hormone signal to the bone marrow to make more red blood cells. The number of red blood cells increases, so more oxygen is carried in the blood.

This is a positive feedback loop

This is a negative feedback loop

This is not a feedback loop

In a negative feedback loop, the response of the system opposes the initial stimulus, helping to maintain homeostasis. In this case, the kidneys sense low oxygen levels in the blood and respond by sending a hormone signal to the bone marrow to produce more red blood cells. The increased production of red blood cells helps to increase the oxygen-carrying capacity of the blood, thus opposing the initial low oxygen levels. This response helps to restore the oxygen levels back to normal and maintain homeostasis, making it a negative feedback loop.

Explanation

In a negative feedback loop, the response of the system opposes the initial stimulus, helping to maintain homeostasis. In this case, the kidneys sense low oxygen levels in the blood and respond by sending a hormone signal to the bone marrow to produce more red blood cells. The increased production of red blood cells helps to increase the oxygen-carrying capacity of the blood, thus opposing the initial low oxygen levels. This response helps to restore the oxygen levels back to normal and maintain homeostasis, making it a negative feedback loop.