Bones, muscles and the senses

Grade 7 Science Worksheet

Circle the best answer.

1. 1.

   Ari learns that a person's eye is healthy, but the optic nerve is damaged. What will most likely happen?

   • The retina still detects light, but the signal cannot reach the brain, so sight is lost.
   • The retina can no longer detect light, so the optic nerve has nothing to send to the brain.
   • The brain sees the light directly through the eye, so sight is the same as before.
   • The lens cannot focus any more, so images are blurry but the person can still see.
2. 2.

   The three small bones in Bo's middle ear are stiff. Sound still reaches the eardrum. What will most likely follow?

   • The cochlea makes sounds louder, so the stiff bones make hearing sharper than before.
   • Vibrations pass poorly from the eardrum to the cochlea, so sounds seem quieter.
   • The eardrum cannot vibrate, so no sound enters the ear and nothing is heard.
   • The auditory nerve stops carrying signals, so sounds seem the same but are not stored.
3. 3.

   A drum sounds near Esme. Which list puts the path of the sound signal in order?

   • Eardrum → three small bones → cochlea → auditory nerve → brain
   • Eardrum → auditory nerve → three small bones → cochlea → brain
   • Cochlea → three small bones → eardrum → auditory nerve → brain
   • Brain → auditory nerve → cochlea → three small bones → eardrum
4. 4.

   Jun touches a hot pan and pulls the hand back before feeling the pain. Which path best fits the reflex?

   • Skin receptor → sensory neuron → spinal cord → brain, with no signal to the arm muscle
   • Skin receptor → sensory neuron → brain → motor neuron → arm muscle, then spinal cord
   • Skin receptor → sensory neuron → spinal cord → motor neuron → arm muscle
   • Arm muscle → motor neuron → spinal cord → sensory neuron → skin receptor
5. 5.

   Distance the ruler fell before the catch, in cm. Ari: 12, 14, 13. Bo: 22, 20, 24. Kira runs a ruler-drop test. A shorter catch distance means a quicker response. Whose reaction is quicker?

   • Bo's, because the ruler fell a longer distance, which shows Bo had more time to react.
   • Ari's, because the ruler fell a shorter distance before Ari caught it each time.
   • Ari's, because 12 is the smallest number and the first number in the table.
   • They are equal, because each person was tested three times with the same ruler.
6. 6.

   Catch distance in cm. Try 1: 24. Try 2: 21. Try 3: 19. Try 4: 17. Try 5: 17. Luz practices the ruler-drop test five times. A shorter catch distance means a quicker response. What does the table best show?

   • The response stayed the same, since the same person caught the ruler on each try.
   • The response got quicker with practice at first, then leveled off at 17 cm.
   • The response got quicker on each try, since the last two tries are equal.
   • The response got slower with practice, since the distances became smaller each try.
7. 7.

   Average catch distance for 10 students. Phone put away: 15 cm. Reading a phone: 22 cm. Milo tests the same 10 students with and without a phone in hand. A shorter catch distance means a quicker response. What do the averages suggest?

   • A distraction changes nothing, since both groups caught the ruler with their hands.
   • A distraction shows that phones slow any person's response, since the averages differ.
   • A distraction speeds the response up, since the average distance is longer with the phone.
   • A distraction seems to slow the response, though a test of 10 students is small.

8. Read this first

   Table (model data)

   Joint P: bends and straightens in one direction. Joint Q: swings forward, back, out to the side and around in a circle. Joint R: turns a bone from side to side around another bone.

9. 8.

   Pia records how three joints can move. Which match of joint to type is correct?

   • P is a hinge, Q is a pivot, and R is a ball-and-socket.
   • P is a pivot, Q is a ball-and-socket, and R is a hinge.
   • P is a hinge, Q is a ball-and-socket, and R is a pivot.
   • P is a ball-and-socket, Q is a hinge, and R is a pivot.
10. 9.

    Ren bends the knee to pull the foot back, as when kicking backward. Which muscle group contracts?

    • The hamstrings on the back of the thigh contract and pull the lower leg back.
    • The quadriceps on the front of the thigh relax and push the lower leg back.
    • The quadriceps on the front of the thigh contract and pull the lower leg back.
    • The calf muscles stretch so that the lower leg is pushed back behind the knee.

11. Table (model data)

    Skeletal: attached to bones by tendons, controlled by choice. Smooth: in the walls of the stomach and intestines, works without choice. Cardiac: in the heart, works without choice.

12. 10.

    Tala compares three muscle kinds. Which one moves bones, is under conscious control, and is attached to bones by tendons?

    • Cardiac muscle, which is in the heart and works without choice.
    • Smooth muscle, which is attached to bones by tendons and can be controlled by choice.
    • Smooth muscle, which is in the walls of the stomach and works without choice.
    • Skeletal muscle, which is attached to bones by tendons and is controlled by choice.