Chromosomes tell a Story

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Students will learn the basic function of chromosomes and understand how they are read to tell a story about us.

Big Idea

Chromosomes are chock full of information.


5 minutes

Warm-Up: Where in a frog will you find a 2n or diploid number of chromosomes? Where would you find an n or haploid number of chromosomes?

This question serves as a review of the content that was taught on Cell Division, Mitosis.

Allow students to ponder the question for several seconds before accepting students’ answers to the question.  Giving students ample time to consider a question allows all learners to have adequate time to consider the question and possible responses.  After a short period of thinking time, allow 2-3 students to share their thoughts.  Ask other students whether they agree or not with the answer and require them to explain before affirming that the answer is correct or not.  This practice helps build an expectation that all students are subject to be asked to respond to a question, whether they volunteer to answer or not.

Encourage students to challenge one another using academic discourse is they feel that the response is incorrect.

Introduce New Material

20 minutes

Explain that students will first engage in a listening activity on Chromosomes, Chromatids, Chromatin, etc.. from Kahn Academy.  Computers or Ipods can be used for this activity:

I like to use the Ipods because I find that they work well independently when listening on the Ipod devices.

Pre-assign the Ipods using a sign-on form to make the distribution and collection of Ipods an efficient process that does not waste instructional time.  As a security measure, require students to sign them out and back in at the end of the activity based on the pre-assigned number.  Utilize a sign-out form and keep it with the Ipod cart.  The form enables students to quickly sign for the Ipod and take it back to their desks.

Display the Ipod Listening Activity and inform students they will need to write ten facts and draw at least one diagram as a performance task with the listening assignment.  Designate a specific amount of time (15-18 minutes) for the assignment and display the timer so that students will be able to self-monitor their progress.   

Students tend to enjoy this learning modality and typically write well-written notes that include vocabulary terms and diagrams that suggest that they are understand the content of the lesson. This is a useful tool for the ELL students, who can benefit from replaying the clip multiple times in order to gain understanding.

After this activity, spend about 5 minutes sharing the key content points. Instruct students to add any new content to their existing notes.

Guided Practice

10 minutes

Inform students that they will engage in an independent study of chromosomes using computers and an interactive site,

Display the What can our chromosomes tell us? assignment. Distribute the assignment questions and computers to students.  Instruct students to use the computer to access the genetics website.

Explain that the assignment requires students to read each of the following sections and write responses to the questions after reading and/or performing the activity in each section:

  • Genetics, Chromosomes and Inheritance
  • What is a chromosome?
  • How do scientists read chromosomes
  • Make a karyotype
  • Using karyotypes to diagnosis genetic disorders

Read the questions in each section aloud.  Instruct students to underline key words in each sentence as you read the questions.  This will help them identify what it is they will need to know or do when they begin the independent work.


Independent Practice

20 minutes

Release students to read sections of the assignment.  Explain that students are expected to complete all 15 questions and perform the interactive activities.  By performing the close read and the activities first, students should be able to write explanatory text in response to questions using relevant and facts and concrete details.

Review the activities of a close read.  Encourage students to write down anything that they think is a key point, write down lingering questions, and then go back to re-read the section before underlining key concepts they've written down before attempting to respond to the questions.  Also encourage students to read small amounts of information in each section, instead of reading the entire section at one time.  Consider downloading the reading material into Kurzweil software for struggling and EL readers who would benefit from the computer-based reading support software that reads the text and defines terms. Note: Kurzweil is a proprietary reading program used in my district to support literacy development.

Walk around the room to monitor students work and ensure that all students are actively engaged in the completion of the task.  

The student work sample that is attached shows that the student was able to glean key information from the activity to construct written responses to the questions.  Her answers are very detailed and written using academic vocabulary.


5 minutes

Display the 5-3-1 ticket out the door.  Instruct students to:

5—List 5 words from the lesson or reading.

3—Share their 5 words with a seat mate then agree on the 3 important words.

1- Partner groups join another partner group and share the 3 words each group came

up with. Then have the 2 groups agree on 1 key word that best represents the content.

Ask each group to share that 1 key word with the whole class and tell why it is the best word to represent the content that was learned today.