Q10
3 marksShort AnswerSection C

Trace the sequence of events which occur when a bright light is focused on your eyes.

Control and Coordination
Control and Coordination
Official Answer

When a bright light is focused on our eyes, the following sequence of events occurs:

  1. The light stimulates the retina of the eye.
  2. The stimulation is converted into electrical signals by the photoreceptor cells (rods and cones) in the retina.
  3. These electrical signals are transmitted to the optic nerve, a bundle of nerve fibers that carries visual information from the eye to the brain.
  4. The optic nerve sends the signals to the brain, where they are processed and interpreted.
  5. The brain sends a response signal through the nervous system to the muscles that control the size of the pupil.
  6. The muscles adjust the size of the pupil to regulate the amount of light entering the eye.
  7. If the light is too bright, the pupil constricts (becomes smaller) to reduce the amount of light entering the eye.
  8. If the light is too dim, the pupil dilates (becomes larger) to allow more light to enter the eye.
lightretinaelectrical signalsoptic nervebrainpupilmuscles

Marking Scheme

  • 11. Light stimulates the retina of the eye.
  • 22. Stimulation is converted into electrical signals by photoreceptor cells.
  • 33. Signals are transmitted to the optic nerve.
  • 44. Optic nerve sends signals to the brain.
  • 55. Brain sends response signal to muscles controlling pupil size.
  • 66. Muscles adjust pupil size to regulate light entry.
  • 77. Pupil constricts if light is too bright.
  • 88. Pupil dilates if light is too dim.

Hint

Think about the process of how light enters the eye and how the eye responds to different light intensities.

Quick Oral Answer

When a bright light is focused on our eyes, the light stimulates the retina, which converts the stimulation into electrical signals. These signals are transmitted to the optic nerve, which sends them to the brain. The brain interprets the signals and sends a response signal to the muscles that control the size of the pupil. The muscles adjust the size of the pupil to regulate the amount of light entering the eye. If the light is too bright, the pupil constricts, and if the light is too dim, the pupil dilates.

Analysis & Explanation

This question requires the student to recall the sequence of events that occurs when a bright light is focused on the eyes. The student should be able to describe the process of how the light stimulates the retina, how the stimulation is converted into electrical signals, and how the signals are transmitted to the brain and interpreted. The student should also be able to explain how the brain responds to the signals and how the muscles adjust the size of the pupil to regulate the amount of light entering the eye.

Common Mistakes

  1. 1Forgetting to mention the role of photoreceptor cells in converting stimulation into electrical signals.
  2. 2Not explaining how the brain interprets the signals and sends a response signal to the muscles.
  3. 3Not describing how the muscles adjust the size of the pupil to regulate light entry.

Interesting Facts

The human eye can process 36,000 bits of information every hour.

The eye can distinguish between over 10 million different colors.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2019?

This question carries 3 marks in the CBSE Class 10 Science 2019 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Control and Coordination" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Control and Coordination" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2019 paper?

This is a Short Answer question from Section C in the CBSE Class 10 Science 2019 paper.