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The Clock That Lives in Your Brain

4th grade nonfiction passage about body clock and sleep: 204 words, six questions, an answer key and vocabulary.

4th grade nonfiction body clock and sleep 204 words

The Clock That Lives in Your Brain

You do not own a wristwatch inside your body, but you do have a clock. Deep in your brain, a tiny group of cells keeps track of time. It works on a cycle of about one day. This body clock tells you when to feel sleepy and when to feel awake.

The clock needs help to stay on time, and its best helper is light. When morning sunshine enters your eyes, a signal tells the clock that a new day has begun. As evening comes and the light fades, your body makes more of a chemical called melatonin. Melatonin helps you feel drowsy.

Bright light at night can confuse the clock. A very bright lamp or screen close to bedtime can send the message that it is still daytime. Then sleepiness may come later than it should.

You can help your clock. Spend time outdoors in the morning. In the evening, turn down the lights and choose quiet things to do, like reading. Try to go to bed around the same time each night.

The body clock also explains jet lag. When a family flies across the world, their clocks are still set to home time. It takes a few days to catch up.

Questions

  1. What does the body clock tell you? in the text

  2. What is the body clock's best helper? in the text

  3. What does your body make more of as evening comes? in the text

  4. What can a very bright screen near bedtime tell your body? in the text

  5. Can you name one way to help your body clock? in the text

  6. Why do people feel jet lag after a long flight to a faraway place? think about it

Words to know

cycle
a set of events that repeats in the same order
melatonin
a chemical your body makes that helps you feel sleepy
drowsy
sleepy and slow
confuse
to make something unclear or mixed up
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One passage, three levels

The same topic and facts written three ways, so a mixed class can read and talk about one text. Each group’s sheet shows only a shape; the key says which is which.

● Easier · 184 words · Flesch-Kincaid grade 2.6

You do not wear a watch inside your body, but you do have a clock. Deep in your brain, a tiny group of cells keeps time. It runs on a cycle of about one day. This body clock tells you when to feel sleepy and when to feel awake.

The clock needs help to stay on time. Its best helper is light. When morning sun gets into your eyes, a signal tells the clock a new day has begun. In the evening, the light fades. Then your body makes more of a chemical called melatonin. Melatonin helps you feel drowsy.

Bright light at night can confuse the clock. A bright lamp or screen near bedtime says it is still day. Then sleepiness can come late.

You can help your clock. Go outside in the morning. In the evening, dim the lights and read or do something quiet. Go to bed at about the same time each night.

The body clock also explains jet lag. When a family flies far away, their clocks still tell home time. It takes a few days to catch up.

▲ This passage · 204 words · Flesch-Kincaid grade 3.4

You do not own a wristwatch inside your body, but you do have a clock. Deep in your brain, a tiny group of cells keeps track of time. It works on a cycle of about one day. This body clock tells you when to feel sleepy and when to feel awake.

The clock needs help to stay on time, and its best helper is light. When morning sunshine enters your eyes, a signal tells the clock that a new day has begun. As evening comes and the light fades, your body makes more of a chemical called melatonin. Melatonin helps you feel drowsy.

Bright light at night can confuse the clock. A very bright lamp or screen close to bedtime can send the message that it is still daytime. Then sleepiness may come later than it should.

You can help your clock. Spend time outdoors in the morning. In the evening, turn down the lights and choose quiet things to do, like reading. Try to go to bed around the same time each night.

The body clock also explains jet lag. When a family flies across the world, their clocks are still set to home time. It takes a few days to catch up.

■ Harder · 211 words · Flesch-Kincaid grade 5.4

You do not carry a wristwatch inside your body, yet you do possess a clock. Deep within your brain, a tiny group of cells keeps track of time. It operates on a cycle of roughly one day. This internal clock tells you when to feel sleepy and when to feel awake.

The clock needs assistance to stay accurate, and its most important helper is light. When morning sunshine enters your eyes, a signal informs the clock that a new day has begun. As evening arrives and the light fades, your body produces more of a chemical called melatonin. Melatonin helps you feel drowsy.

Bright light at night can confuse the clock. A very bright lamp or screen close to bedtime can send the message that it is still daytime, and then sleepiness may arrive later than it should.

You can support your clock in several ways. Spend time outdoors in the morning. In the evening, turn down the lights and choose quiet activities such as reading. Try to go to bed at around the same time every night.

The body clock also explains jet lag. When a family flies across the world, their clocks are still set to home time, and it takes a few days for them to catch up.

Download as one PDF

How to use it

  1. Press Read it big (or B) to put the text on the projector, or Full screen (F) to fill the whole screen.
  2. Ask the questions one at a time and use Show answer when the class has decided. A shows or hides every answer.
  3. Print student copy for the class, or Print with answers for yourself.

Ideas for class

  • Before reading, put cycle, melatonin, drowsy and confuse on the board with their meanings from the Words to know section and have students predict what the text will be about.
  • Read it aloud once while students follow along, then have them reread it alone or with a partner. At a calm 100 words a minute it takes about 2 minutes to read aloud.
  • Use the Read it big button (or B) to put the text on the projector, and Show answer on one question at a time so the class commits to an answer first.
  • Question 6 asks the reader to infer. Ask students to point to the words in the passage that led them to their answer.
  • Ask students to write one question the passage did not answer, then look for the answer in a book or on a classroom screen.
  • Print the student copy for independent work and keep the answer-key copy for yourself.

Related

Questions

What reading level is "The Clock That Lives in Your Brain"?

It was written for 4th grade. It has 204 words and works out to a Flesch-Kincaid grade level of about 3.4. That is a formula's estimate from sentence length and syllables, and it is not a Lexile or a guided reading level, so check it against your students.

What do the questions ask?

There are six. 5 ask for something the text says directly and 1 ask the reader to work something out from clues. Each has an answer in the key, and the answers are written as a teacher would accept them, not as the only possible wording.

How long does it take to read?

About 2 minutes read aloud at 100 words a minute. For a one-minute fluency check, paste it into the fluency timer and use the word count.

Can I print it?

Yes. Print student copy gives the passage, the questions with lines to write on, and the word meanings. Print with answers gives the same page with the answers filled in. Both are made in your browser.

Is this passage from a published book?

No. It was written for Peabody Teach, so there is no book to buy and no login to read it.

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