Question 1

Which of the following best describes homeostasis in biological systems?

Accepted Answer

The maintenance of a relatively constant internal environment despite external changes.

Question 2

A person is exposed to a hot environment. Which sequence correctly describes the negative feedback loop for thermoregulation?

Accepted Answer

Stimulus (increased temperature) → Receptor → Control center → Effector (sweat glands) → Response (sweating) → Decrease in body temperature

Question 3

Which of the following is NOT a factor for which organisms have tolerance limits?

Accepted Answer

Light intensity

Question 4

What is the main difference between negative and positive feedback in homeostatic control?

Accepted Answer

Negative feedback reverses the original stimulus, while positive feedback amplifies it.

Question 5

A patient with untreated diabetes mellitus is likely to experience which of the following symptoms due to a failure in homeostatic regulation?

Accepted Answer

Hyperglycaemia, increased urination, and dehydration

Question 6

Which hormone is responsible for increasing blood glucose levels, and what is its primary target organ?

Accepted Answer

Glucagon; liver

Question 7

Which of the following best explains why enzymes require homeostasis to function optimally?

Accepted Answer

Enzymes have specific temperature and pH ranges where their active sites maintain the correct shape for substrate binding.

Question 8

Which of the following is a correct sequence for the stimulus-response model?

Accepted Answer

Stimulus → Receptor → Transmission → Effector → Response

Question 9

A person is dehydrated after running a marathon. Which hormone is released to restore water balance, and what effect does it have on the kidneys?

Accepted Answer

Antidiuretic hormone (ADH); increases water reabsorption in the nephron

Question 10

Which of the following best describes the role of sensory receptors in homeostasis?

Accepted Answer

They detect changes in the internal or external environment and initiate nerve impulses.

Question 11

Which of the following is a real-life example of negative feedback?

Accepted Answer

Regulation of blood glucose by insulin and glucagon

Question 12

A person with central diabetes insipidus (CDI) is unable to produce ADH. What is a likely consequence for their blood pressure?

Accepted Answer

Blood pressure will decrease due to reduced water reabsorption and lower blood volume.

Question 13

Which of the following statements correctly compares the nervous and endocrine systems?

Accepted Answer

The nervous system acts rapidly and specifically, while the endocrine system acts more slowly and has widespread effects.

Question 14

Which of the following best describes the action of adrenaline during the 'fight or flight' response?

Accepted Answer

Adrenaline increases heart rate, blood glucose, and blood flow to muscles to prepare the body for action.

Question 15

Which of the following is a correct explanation for why hyperventilation increases blood pH?

Accepted Answer

Hyperventilation removes more CO$$_2$$ from the blood, reducing carbonic acid and increasing pH.

Question 16

Which of the following best describes the effect of thyroxine on metabolism?

Accepted Answer

Thyroxine increases the basal metabolic rate, promoting heat and energy production.

Question 17

Which of the following is a multi-step example of how the nervous and endocrine systems work together to regulate body temperature?

Accepted Answer

Sensory receptors detect cold → hypothalamus activates nerve impulses → muscles shiver (nervous) and pituitary releases TSH → thyroid releases thyroxine (endocrine) → increased metabolism and heat production

Question 18

Which of the following is the correct formula for the conversion of carbon dioxide in the blood to carbonic acid?

Accepted Answer

$$ \mathrm{CO_2 + H_2O \rightarrow H_2CO_3} $$

Homeostasis and Regulation: Nervous and Endocrine Systems

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