Bones, muscles and the senses

Grade 7 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Ari says the eyes do all the seeing and the brain only stores pictures. Which case best argues against this?

   • A person with a damaged eye can still see a little, which means the eye is not needed.
   • A person with healthy eyes cannot see after damage to the visual part of the brain.
   • A person who wears glasses sees better, which shows the lens does the seeing.
   • A person with healthy eyes sees clearly, which shows the brain has no job in sight.
2. 2.

   10 students named the flavor of a jelly bean. Nose open: 9 right. Nose pinched shut: 3 right. Bo says taste alone tells the flavor of a jelly bean. What does the test best show?

   • Smell is the main sense in flavor, since 3 students were right with a nose pinched.
   • Smell adds a lot to flavor, since pinching the nose cut right answers from 9 to 3.
   • Taste alone gives the flavor, since the tongue was used in both tests.
   • Pinching the nose made tongue receptors stop working, so taste was lost for the test.
3. 3.

   The smallest gap felt as two touches. Fingertip: 3 mm. Palm: 11 mm. Forearm: 38 mm. Back: 60 mm. Esme says a fingertip and a forearm feel touch the same way because both are skin. Which statement is best supported?

   • Fingertips are more sensitive: they feel two close touches that the forearm feels as one.
   • Each place feels touch the same, since each of them is made of skin.
   • The forearm is more sensitive than the palm, since 38 mm is a bigger gap than 11 mm is.
   • The back is the most sensitive, since 60 mm is the largest number in the whole table.
4. 4.

   Kira's ankle is swollen and sore after a fall. An X-ray shows no broken bone. Which cause fits best?

   • The joint has no fluid left, so a break must be hidden behind the swollen skin.
   • A ligament at the joint was stretched or torn, which an X-ray of bone would not show.
   • A tendon joined bone to bone and has torn, which an X-ray of bone would show.
   • A muscle pushed the bone out of place, which an X-ray of bone would show clearly and quickly.
5. 5.

   Milo reads about a person with an injury low on the spinal cord: both arms feel and move, but the legs do not. Which explanation fits best?

   • The signals between the brain and the legs pass through the damaged part of the spinal cord.
   • The brain cannot feel the legs, so the leg muscles are no longer joined to bones by tendons.
   • The leg bones were damaged, so the brain can no longer send signals to any muscles.
   • The arms use a different brain, so the injury cannot affect signals to the legs.
6. 6.

   Noah puts a hand in warm water, and after a minute the water feels less warm. The thermometer reads the same. What best explains this?

   • The brain forgets the temperature, so the receptors stop sending signals altogether.
   • The hand warmed up to match the water, so the receptors can no longer feel any change.
   • The water cooled down, so the receptors correctly report a lower temperature than before.
   • Skin receptors respond less to a steady temperature, so the signals to the brain weaken.
7. 7.

   Pia wants to test whether practice makes reaction time quicker with the ruler drop. Which plan is best?

   • Test the students five times each and record just the longest distance for each person in the group.
   • Test the same students five times, with the same ruler and method, recording each distance.
   • Test students five times each but change the ruler and the starting hand each time.
   • Test one student once, then test a different student after ten tries and compare them.
8. 8.

   Ren wants to find out whether people respond more quickly to a sound or a sight. Which plan is best?

   • Test half the students with a sound signal and half with a sight signal, one trial each.
   • Test the same students with a sound and a sight signal, in random order, many times each.
   • Test the students with a loud sound and a dim light, and compare how they respond.
   • Test the students with a sound signal first, then a sight signal, and compare their tiredness.
9. 9.

   Tala wants to test whether pupils get wider in dim light. Which plan is best?

   • Measure the same person's pupils in a bright room, then a dim room, with the same camera.
   • Measure the same person's pupils in a bright room and in a dim room, but change the camera.
   • Measure one person's pupils in a bright room and another person's pupils in a dim room.
   • Measure the same person's pupils in a dim room alone, and compare them with a drawing.
10. 10.

    Zee compares two reaction studies. Which study gives the stronger evidence that practice helps?

    • Neither, because a study about reaction cannot be used as evidence for anything.
    • Study 2, because it has more students and tries, and every test was done the same way.
    • Study 1, because it was shorter, so the students stayed fresh through all of the tries.
    • Study 1, because it used different rulers, which makes the results more varied and more real.