Question

feedback loop exit ticket

1. (1pts) which of the following best defines the concept of homeostasis in biological systems?

a) the process by which organisms increase their population size to adapt to environmental changes.
b) the process by which organisms maintain stable internal conditions despite changes in their external environment.
c) the process by which organisms undergo growth and development from a single cell to a complex multicellular organism.
d) the process by which organisms produce energy from food and oxygen through cellular respiration.

1. (1pts) what would happen on a hot day if your brain did not receive input that your body was starting to heat up?

a) you would start to sweat
b) you would start to overheat
c) you would start to shiver
d) you would not feel any effect at all

the graph shows how cortisol levels change during the day. cortisol increases the production of substance z through positive feedback.

1. (1pts) if no other feedback affects substance z, at which point would the level of substance z be the highest? circle the letter (a, b, c, or d) on the graph below. graph: cortisol concentrations over a 24-hour period, with points a, b, c, d

1. (2pts) complete the sentence below by circling the type of feedback described in the scenario below and provide an explanation supporting your choice.

scenario: during childbirth, the stretching of the cervix during labor causes the release of oxytocin, which stimulates further contractions. these contractions lead to more stretching and more oxytocin release, intensifying the contractions until the baby is delivered.
this is an example of negative / positive feedback because...

Explanation:

Question 1

• Option A: Population growth adaptation is not homeostasis. Homeostasis is about internal stability, not population size change.
• Option B: Homeostasis is defined as the process where organisms maintain stable internal conditions (like temperature, pH, etc.) even when the external environment changes. This matches the definition.
• Option C: Growth and development from a single cell to multicellular is about development, not homeostasis.
• Option D: Energy production via cellular respiration is a metabolic process, not homeostasis.

• Option A: Sweating is a response to heat, but it requires the brain to detect the heat and trigger the response. If the brain doesn't get the input, it can't trigger sweating.
• Option B: The brain's role in thermoregulation is to detect when the body is heating up and initiate cooling mechanisms (like sweating). If the brain doesn't receive the input that the body is heating up, it won't trigger those cooling mechanisms, so the body would start to overheat.
• Option C: Shivering is a response to cold, not heat.
• Option D: The body would be affected as it can't regulate its temperature properly without the brain's input.

Cortisol increases the production of Substance Z through positive feedback. Positive feedback means that as cortisol levels increase, Substance Z production increases, which in turn would further increase cortisol (but here we are looking at Substance Z). The graph shows cortisol concentration over 24 hours. Point B is the peak of cortisol concentration. Since cortisol increases Substance Z via positive feedback, the highest cortisol level (at B) would lead to the highest Substance Z level (because more cortisol means more Substance Z production, and positive feedback reinforces this). So Substance Z would be highest at point B.

Answer:

B. The process by which organisms maintain stable internal conditions despite changes in their external environment.

Question 2