1. 1
   A student researching the endocrine system finds that the pancreas releases hormones directly into the bloodstream to travel to target organs elsewhere in the body, unlike the digestive system's exocrine glands, which release digestive enzymes through a duct into the gut.

   (a)

   How are hormones such as those released by the pancreas transported to their target organs?

   [1 mark]

   • AVia the bloodstream
   • BVia nerve fibres
   • CVia ducts
   • DVia the digestive system only

   (b)

   Which of these glands is correctly matched with a hormone it produces?

   [1 mark]

   • AThyroid — adrenalin
   • BPancreas — insulin and glucagon
   • CTestes — thyroxine
   • DAdrenal glands — FSH

   (c)

   Explain one key difference between how the pancreas releases digestive enzymes into the gut and how it releases hormones such as insulin into the body.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A marathon runner competing in a race on a hot day begins to overheat. Her skin becomes flushed and she sweats heavily, but towards the end of the race, as she becomes exhausted, her core body temperature continues to climb despite these responses.

   (a)

   Which change occurs in the blood vessels supplying the skin as the runner's body works to lose more heat?

   [1 mark]

   • AVasoconstriction
   • BVessels close completely
   • CVasodilation
   • DNo change

   (b)

   Which part of the brain coordinates the body's thermoregulatory responses by detecting blood temperature?

   [1 mark]

   • ACerebellum
   • BMedulla oblongata
   • CCerebral hemisphere
   • DHypothalamus

   (c)

   Explain how sweating helps to cool the runner's body.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A school health screening measures two Year 11 students as part of a study into type 2 diabetes risk factors. Student P has a mass of 90 kg and a height of 1.5 m. Student Q has a mass of 65 kg and a height of 1.7 m.

   (a)

   Calculate the BMI of Student P (mass 90 kg, height 1.5 m) and Student Q (mass 65 kg, height 1.7 m), using BMI = mass (kg) ÷ height (m)², and state which student has a BMI classified as within the obese range (BMI 30 or above).

   [3 marks]

   (b)

   Explain why a high BMI, such as Student P's, is considered a risk factor for developing type 2 diabetes, and evaluate why BMI alone might not always accurately reflect a person's risk of type 2 diabetes.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A firefighter is fighting a blaze inside a burning building, wearing heavy protective clothing in intense heat. As the situation becomes dangerous, her adrenal glands release adrenalin, and at the same time her body works to prevent her core temperature rising to a dangerous level while she continues to sweat heavily.

   (a)

   Explain how adrenalin released by the firefighter's adrenal glands would prepare her body to respond to the dangerous situation, including its effect on heart rate and blood glucose concentration.

   [6 marks]

   (b)

   Explain how the firefighter's body works to prevent her core temperature rising to a dangerous level while she is working in intense heat, and explain why heavy sweating in this situation could also affect her body's water balance.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   A patient has had part of her thyroid gland surgically removed due to a growth. Several weeks after surgery, blood tests show her thyroxine levels are lower than normal, and she is prescribed a daily thyroxine replacement tablet to keep her metabolic rate within a healthy range.

   (a)

   Which gland releases TSH, which stimulates the thyroid to produce thyroxine?

   [1 mark]

   • AAdrenal gland
   • BPituitary gland
   • CPancreas
   • DHypothalamus

   (b)

   What is the direct effect of low thyroxine levels on the hypothalamus, as part of the negative feedback control of thyroxine?

   [1 mark]

   • AIt inhibits the hypothalamus from releasing TRH
   • BIt has no effect on the hypothalamus
   • CIt stimulates the hypothalamus to release more TRH
   • DIt stimulates the pancreas to release insulin

   (c)

   Explain how the negative feedback system normally controlling thyroxine levels would respond if the patient's thyroxine tablet dose is too high, causing her blood thyroxine level to rise above normal.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   A biology class studies a description of nephron function: blood entering the glomerulus is filtered into the Bowman's capsule, removing small molecules such as glucose, water, salts and urea from the blood, while blood cells and large proteins remain in the blood. As the filtrate passes along the nephron tubule, useful substances such as glucose are selectively reabsorbed back into the blood.

   (a)

   Which large components are prevented from entering the filtrate at the glomerulus and Bowman's capsule due to their size?

   [1 mark]

   • AGlucose and water
   • BUrea and salts
   • CWater and urea
   • DBlood cells and large proteins

   (b)

   What happens to glucose as the filtrate passes along the nephron tubule under normal conditions?

   [1 mark]

   • AIt is selectively reabsorbed back into the blood
   • BIt remains entirely in the filtrate and is excreted in urine
   • CIt is broken down within the tubule
   • DIt is filtered out at the glomerulus only

   (c)

   Explain why a healthy person's urine does not normally contain any glucose, even though glucose is present in the fluid entering the Bowman's capsule.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   A couple experiencing difficulty conceiving naturally are referred to a fertility clinic. Tests show the woman does not regularly release eggs from her ovaries. Her doctor prescribes a course of clomifene therapy before considering IVF treatment.

   (a)

   Explain how clomifene therapy is intended to help the woman ovulate regularly.

   [3 marks]

   (b)

   If clomifene therapy alone does not lead to a successful pregnancy, describe how IVF treatment could be used instead, and evaluate one advantage and one disadvantage of IVF compared with clomifene therapy alone.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   A clinic reviews two patients. Patient X has had type 1 diabetes since childhood and injects insulin at mealtimes. Patient Y was recently diagnosed with type 2 diabetes in her fifties and initially manages her condition through diet and exercise alone, without medication.

   (a)

   Explain the different underlying cause of Patient X's type 1 diabetes compared with Patient Y's type 2 diabetes, and explain why Patient X needs to inject insulin while Patient Y may initially manage her condition without insulin.

   [6 marks]

   (b)

   Insulin and glucagon are both hormones released by the pancreas. Explain how these two hormones work together to keep Patient Y's blood glucose concentration within a normal range between meals, and evaluate why type 2 diabetes, unlike type 1, is often linked to lifestyle factors.

   [6 marks]

   Total for question 8: 12 marks

End of questions