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Lesson/Homework/Test (DNA, RNA, cell structure)

Objectives:  Discuss cell structure, the purpose of DNA and RNA

Sub-objectives:  Link between math and science

Question:  How does the body know where to correctly place organs?

 

How The Body Determines Where Organs Are Placed

La Jolla, Calif. -- A Salk Institute team of biologists, mathematicians, and physicists has uncovered a novel paradigm for CELL communication that provides new insights into the complex question of how the body determines where ORGANS are placed.

The study focused on a fundamental question: how the body tells left from right. Although humans look fairly symmetric on the outside, their inner organs are placed quite asymmetrically; for example, the heart points to the left and the liver lies to the right side.

"We know that in the phase of development, there is a genetic cascade that leads to the proper placement of organs. If that cascade is disrupted, the results can lead to major problems or be fatal," said professor Belmonte. Still, scientists did not have a clear understanding of what triggers the genetic cascade that defines organ placement. Belmonte's group focused on the activity of the Notch pathway, an important player during embryo development and a key factor for proper left-right asymmetry, as the same group and others had learned earlier this year.

"We knew that Notch activity was necessary for the normal, left-sided expression, but we were clueless as to what was activating Notch preferentially on the left side," said Angel Raya, lead author of the paper. "We examined several factors known to participate early in the establishment of the left-right axis, but none was responsible for what we were seeing."

Belmonte and his team characterized a highly complex chain of events leading to Notch activation, and resorted to mathematics to model the dynamics of this process. The model allowed the team to perform thousands of experiments in the computer (simulations), and pinpoint the factors most likely to regulate Notch activity in the specific fashion seen in the EMBRYO.

"The model pointed in the direction of extracellular CALCIUM, and we were absolutely thrilled when we visualized that, indeed, extracellular calcium accumulated normally on the left side of the embryo. The mathematical model that we developed saved us years of bench work and led to new insights about a biological problem," said Belmonte. "We are very excited about this multidisciplinary approach to biology, and we believe that collaborative approaches between biologists, mathematicians, and physicists working together will lead to long-term breakthroughs in biological research."

Instructions: Please number the lines in the article, highlight concepts and terms, and place notes along the margins. (5 pts.)

Questions

Please write all answers except multiple choice on a separate sheet of paper.

  1. Define and use all underlined words in a sentence. (10 pts.)
  2. Create a divided page graphic organizer study guide using the CAPITALIZED bold letter words. (10 pts.)
  3. What is a cell?  Circle the best answer.  Cite the sentence and paragraph in the article, page in the text, or other source. (15 pts.)
    1. Unique organ in the body
    2. Basic unit of structure and function in living things
    3. Little organelles that control our lives
    4. None of the above

 

 

 

 

 

 

  1. The study focused on what?  Circle the best answer.  Cite the sentence in the article, page in the text, or other source. (10 pts.)
    1. how cells divide
    2. how we learn to speak
    3. how cells make food
    4. how the body tells left from right

 

  1. If the genetic cascade is disrupted what may happen to a person’s organs?  Circle the best answer.  Cite the sentence in the article, page in the text, or other source. (10 pts.)
    1. nothing
    2. a person will walk backwards all his life
    3. our organs may be placed wrong and cause severe problems
    4. one organ will do the job of another organ

 

  1. Computer mathematical simulations pointed in the direction of what chemical or element as the cause of how the body tells left from right?  Circle the best answer.  Cite the sentence in the article, page in the text, or other source. (10 pts.)
    1. Salt
    2. Iron
    3. Calcium
    4. Carbon

 

  1. Somehow calcium acts as trigger mechanism for the correct placement of organs within the human body.  According to article there is a genetic “cascade” dictating the sequence of events leading to the proper placement of organs.  How might understanding this process be helpful to people in the future?  Use your imagination! (20 pts.)

 

Extra Credit:  (2 pts. each)

  1. What is a physicist?
  2. What does the term  “trigger” mean in the third paragraph?
  3. What is the chemical symbol for Calcium?
  4. What does the term “extracellular” mean in the last paragraph?
  5. What does the phrase “multidisciplinary approach” mean as stated in the last paragraph?

 

Research question:  (15 pts.)

  1. List three major organs in the human body and state what the function of each one is.  Use a graphic organizer or concept map to outline or organize your information.