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Personatges:

Lynn Margulis

Tema: The cell

Competències

Competència en Comunicació Lingüística

Competència Matemàtica, en ciència, tecnologia i enginyeria

Competència personal, social i aprendre a aprendre

Matèries i cursos per Sistema Educatiu

Espanya > Biologia i Geologia > 4t ESO > La cèl·lula

Enunciat

<img title="Women's Legacy logo" src="//inclusion.womenslegacyproject.eu/images/LogoWL.svg" /><hr />We owe the theory of endosymbiosis to Lynn Margulis. This theory explains the emergence of eukaryotic cells from primitive prokaryotic organisms. The following diagram summarizes the theory:&nbsp; &nbsp;
<img style="display: block; margin-left: auto; margin-right: auto;" title="endosymbiosis" src="//inclusion.womenslegacyproject.eu/uploads/resume/attachment/4319/Imagen_1.png" alt="endosymbiosis" width="435" height="510" />
Figure 1: Events that supposedly led to the appearance of mitochondria and chloroplasts. Occurred through two independent processes of endosymbiosis, or primary endosymbiosis.Taken from: <a href="https://mmegias.webs.uvigo.es/02-english/5-celulas/1-endosimbiosis.php">https://mmegias.webs.uvigo.es/02-english/5-celulas/1-endosimbiosis.php&nbsp;</a> &nbsp;
<img style="display: block; margin-left: auto; margin-right: auto;" title="Comparative structure of prokaryotes, chloroplasts and mitochondria" src="//inclusion.womenslegacyproject.eu/uploads/resume/attachment/4320/imagen_CHolorplast__bacterium.png" alt="Estructura comparada de procariotas, cloroplastos y mitocondrias" width="399" height="246" />
Figure 2: Comparative structure of prokaryotes, chloroplasts and mitochondria.Taken from:<a href="http://www.biologia.edu.ar/botanica/tema8/8-3organulo.htm#Fig%2016">http://www.biologia.edu.ar/botanica/tema8/8-3organulo.htm#Fig%2016</a> 
Look at the two figures above and answer the following questions:&nbsp; 1. What similarities do you see in the structure of chloroplasts, mitochondria, and bacteria?&nbsp; 2. Look at figure 1 and determine:&nbsp; a. How many endosymbioses gave rise to animal cells? &nbsp; b. How many were necessary to originate plant cells? &nbsp; &nbsp; 3. Based on the above: Where do mitochondria come from? And chloroplasts?&nbsp; 4. Will plant cells have mitochondria? &nbsp; 5. Briefly explain Lynn Margulis's theory of endosymbiosis, indicating what clues could have led her to propose such a theory. Why do you think it is called endosymbiosis and not just symbiosis?&nbsp; &nbsp;

Observacions i context

Lynn Margulis was a contemporary of the astronomers Carl Sagan and Robert Whitaker, with whom she proposed a new classification of living things into five kingdoms.
Lynn Margulis is one of the scientists who have contributed with her proposals to the development of evolutionary biology. Some of them, such as Antoinette Brown Blacwell, dared to question some of Darwin's conclusions, who considered that "evolution had made men superior to women." Others like Barbara McClintock or Esther Lederberg discovered transposable genetic elements and horizontal gene transfer in bacteria, respectively. These discoveries have subsequently been of great importance to understand evolution.

Descripció

This is a short question and answer activity on the theory of endosymbiosis. Objective: Students have to deduce and write the most significant statements of said theory through the interpretation of drawings.

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