16.1 principles of homeostasis

Question 1

what is homeostasis?

Answer 1

maintenance of an internal environment within restricted limits in organisms

Question 2

explain the importance of homeostasis- water potential

Answer 2

• cells shrink or burst due to water leaving or entering

- by osmosis

Question 3

explain how control mechanisms work

Answer 3

• optimum
• receptor detects any deviation from optimum
• coordinator sends instructions to effector
• effector (muscle or gland) brings about the changes needed to return the system to optimum point
• feedback mechanism

Question 4

what is positive feedback?

Answer 4

deviation from an optimum point results in an even greater deviation from the normal

Question 5

what is negative feedback?

Answer 5

deviation from the optimum point results in the system returning to normal

Question 6

explain why maintaining a constant temperature is important in mammals

Answer 6

• maintaining a constant temperature is important because enzymes function within a narrow range of temperatures
• fluctuations may lead to enzymes being denatured

Question 7

suggest why maintaining a constant blood glucose concentration might be important in mammals

Answer 7

• maintaining a constant blood glucose concentration is important in ensuring a constant water potential and reliable source of glucose for respiration
• fluctuations may lead to cells shrinking or bursting so cells cannot operate