InThinking Revision Sites

INTHINKING REVISION SITES

Own your learning

Why not also try our independent learning self-study & revision websites for students?

We currenly offer the following DP Sites: Biology, Chemistry, English A Lang & Lit, Maths A&A, Maths A&I, Physics, Spanish B

"The site is great for revising the basic understandings of each topic quickly. Especially since you are able to test yourself at the end of each page and easily see where yo need to improve."

"It is life saving... I am passing IB because of this site!"

Basic (limited access) subscriptions are FREE. Check them out at:

www.StudyIB.net

Endosymbiosis - Nature of Science

  • /
  • SL Core /
  • Cells: Activities for Learning /
  • Endosymbiosis - Nature of Science

The idea that mitochondria once existed as free living bacteria and that a simple cell engulfed one of these bacterial cells and promptly became a eukaryote cell is a difficult idea to ‘prove’. The fact that this happened millions of years ago doesn't help the science but is a great illustration of the nature of science. This story of a biologist’s tenacity and ingenuity in her research over sixteen years illustrates some important ideas about the nature of science. Read the webpages and answer the questions to gain an insight into the scientific method.

Lesson Description

Key ideas about the nature of science

  • Science can test hypotheses about events that happened long ago.
  • Scientific ideas are tested with multiple lines of evidence.
  • Science is a community endeavor - new discoveries depend on a the scientific community.
  • Scientific ideas evolve with new evidence.
  • The scientific method can overcome individual biases.

Activity 1: Study the work of Lynn Margulis and her endosymbiosis research?

Read the first five pages of the article from Berkeley University, A world under the microscope

This diagram shows the flow of activity in the 'exploration and discovery' of ideas in Science.  (Nature of Science)


Screenshot from: http://undsci.berkeley.edu/article/scienceflowchart

Activity 2: Answer the following questions using Endosymbiosis student worksheet

  1. Which aspects of 'exploration and discovery' lead Lynn Margulis to begin her research into the theory of endosymbiosis? (click the eye to display a model answer)

This diagram shows steps in the testing of ideas illustrating how scientists gather data to support or falsify their ideas.


Screenshot from: http://undsci.berkeley.edu/article/scienceflowchart

  1. Outline the hypothesis which Lynn Margulis stated at the start of her research into endosymbiosis.
  2. In what ways was the scientific community an obstacle to the acceptance of the research?
  3. Which parts of the data she collected were supportive of the hypothesis?
  4. Which parts of the data were contradictory or inconclusive?
  5. How did she use evidence which opposed a hypothesis to support her own hypothesis?

Teachers' notes

This activity works well if you print each page from the article just once (or twice in a large class) and ask students to read just one page and then to explain their pages to the class in a logical order.

Steps for running the activity:

  1.  Give out a page to each student
  2.  Silent reading (5 minutes) - highlight key points and any questions in the text
  3.  Sharing - tell a partner about your page, and listen to them describing their page (10 minutes)
  4.  Note-it - write a short summary of the main idea on a sticky note.
  5.  Each student uses their sticky note and the highlights to explain what information is in each page.

The evidence for the theory of endosymbiosis is a great opportunity to review the structure of prokaryote and eukaryote cells.

There is also an opportunity to introduce the idea of the three Domains of classification, as the Archae (bacteria) are mentioned in the information.