Skip to content
← Back to lesson

Success Homeschool

Year 9 Science · The nervous system and reaction time

Name: ______________________

Date: ____________

  1. 1. Which part of the body is an effector?

    • ☐ (a) The retina of the eye
    • ☐ (b) A muscle in the arm
    • ☐ (c) The spinal cord
    • ☐ (d) A sensory neuron

  2. 2. Why is a reflex faster than catching a ruler?

    • ☐ (a) Reflexes use stronger muscles
    • ☐ (b) Reflexes do not use neurons
    • ☐ (c) The reflex pathway is shorter and does not need a conscious decision
    • ☐ (d) Reflexes only happen in the hand

  3. 3. Which is the correct order?

    • ☐ (a) Stimulus → receptor → sensory neuron → CNS → motor neuron → effector
    • ☐ (b) Receptor → stimulus → CNS → sensory neuron → effector → motor neuron
    • ☐ (c) Stimulus → effector → CNS → receptor → motor neuron → sensory neuron
    • ☐ (d) CNS → stimulus → receptor → effector → sensory neuron → motor neuron

  4. 4. Why should you repeat the ruler test several times?

    • ☐ (a) To make the ruler fall faster
    • ☐ (b) To tire out your partner
    • ☐ (c) To change the independent variable
    • ☐ (d) To reduce the effect of random variation and get a reliable average

  5. 5. Which is a reflex action?

    • ☐ (a) Writing your name
    • ☐ (b) Blinking when something flies towards your eye
    • ☐ (c) Choosing a song
    • ☐ (d) Catching a ball in cricket

  6. 6. Catches were 14 cm, 15 cm and 16 cm. What is the average distance in cm? (number)

  7. 7. Using the table, what is the reaction time in seconds for a 10 cm catch? (decimal)

  8. 8. The brain and spinal cord together are called the central ______ system.

Answer sheet

  1. 1. A muscle in the arm — Effectors are muscles or glands that carry out a response.
  2. 2. The reflex pathway is shorter and does not need a conscious decision — Reflexes bypass conscious decision-making, so the pathway is shorter.
  3. 3. Stimulus → receptor → sensory neuron → CNS → motor neuron → effector — Information travels from the stimulus, through the CNS, to the effector.
  4. 4. To reduce the effect of random variation and get a reliable average — Averaging repeated trials makes results more reliable.
  5. 5. Blinking when something flies towards your eye — Blinking to protect the eye is automatic.
  6. 6. 15 — (14 + 15 + 16) ÷ 3 = 45 ÷ 3 = 15 cm.
  7. 7. 0.14 — The table shows 10 cm ≈ 0.14 s.
  8. 8. nervous — They make up the central nervous system.

© Success Tutoring · homeschool.successtutoring.com · Free for home and personal use. Awaiting educator review.