WA1 Practice Paper: Weighted Assessment 1 — question paper

Section A: Multiple-choice questions[10 marks]

Answer all questions. For each question, write the letter (A, B, C or D) of the correct answer.

1. 1

   Homeostasis is the maintenance of

   1. Aa constant external environment
   2. Bbody temperature at 25 °C
   3. Ca constant internal environment within narrow limits
   4. Dunchanged blood glucose at all costs
   ( )
2. 2

   In negative feedback, the corrective mechanism acts

   1. Ain the opposite direction, cancelling the change
   2. Bbefore the change is detected
   3. Cin the same direction as the change
   4. Donly on the brain
   ( )
3. 3

   On a cold day, blood flow through the skin capillaries decreases because

   1. Athe arterioles dilate
   2. Bsweating increases
   3. Cshivering stops
   4. Dthe arterioles constrict
   ( )
4. 4

   Insulin lowers blood glucose by making the liver

   1. Abreak down glycogen into glucose
   2. Bconvert glucose into glycogen
   3. Crelease glucose into urine
   4. Dsecrete more insulin
   ( )
5. 5

   Insulin and glucagon are secreted by the

   1. Aliver
   2. Bpituitary gland
   3. Cislets of Langerhans in the pancreas
   4. Dkidneys
   ( )
6. 6

   Type 2 diabetes is managed first by

   1. Aa balanced diet and regular exercise
   2. Bdaily insulin injections from diagnosis
   3. Cavoiding all exercise
   4. Ddrinking more water
   ( )
7. 7

   A reflex arc runs

   1. Aeffector → motor neurone → relay → sensory → receptor
   2. Breceptor → motor neurone → relay → sensory → effector
   3. Csensory neurone → effector → receptor → relay → motor neurone
   4. Dreceptor → sensory neurone → relay neurone → motor neurone → effector
   ( )
8. 8

   To focus on a near object, the lens becomes

   1. Athinner as the ciliary muscles relax
   2. Bfatter and rounder as the ciliary muscles contract
   3. Cflatter as ligaments tighten
   4. Dfixed in shape
   ( )
9. 9

   Which pathogen reproduces only inside living host cells?

   1. Aviruses
   2. Bbacteria
   3. Cfungi
   4. Dprotozoa
   ( )
10. 10

    Antibiotics are ineffective against influenza because influenza is caused by a

    1. Abacterium with a cell wall
    2. Bfungus
    3. Cvirus with no cell wall or metabolism
    4. Dtoxin
    ( )

Section B: Structured questions[30 marks]

Answer all questions in the spaces provided.

1. 1

   Temperature regulation on a hot afternoon.

   1. (a)

      Name the control centre for body temperature and the receptors that detect external heat.

      [3]
   2. (b)

      Describe two mechanisms that increase heat loss, explaining how each works.

      [4]
   3. (c)

      Explain why the body’s response to cold includes shivering.

      [3]
2. 2

   Blood glucose regulation.

   1. (a)

      A student’s blood glucose rises from 90 mg/100 cm³ to 150 mg/100 cm³ after a meal. Calculate the percentage increase.

      increase =%[2]
   2. (b)

      Name the hormone released in response, its source, and its effect on the liver.

      [4]
   3. (c)

      Explain why insulin and glucagon are described as antagonistic hormones.

      [2]
   4. (d)

      State one risk factor for type 2 diabetes and one way a patient can manage it.

      [2]
3. 3

   Coordination: reflexes, the eye and disease.

   1. (a)

      List the five parts of a reflex arc in order.

      [3]
   2. (b)

      In bright light, describe the muscle actions in the iris and their effect on the pupil.

      [2]
   3. (c)

      A pupil’s diameter falls from 5.0 mm to 2.0 mm. Calculate the percentage constriction.

      constriction =%[2]
   4. (d)

      State one reason antibiotics cannot treat influenza and one measure that reduces its spread.

      [3]