Margulis

Definition

Lynn Margulis was a biologist whose work on endosymbiotic theory transformed our understanding of the origins of eukaryotic cells. She proposed that organelles like mitochondria and chloroplasts originated from symbiotic relationships between primitive eukaryotic cells and certain prokaryotes.

5 Must Know Facts For Your Next Test

1. Margulis' endosymbiotic theory suggests mitochondria and chloroplasts were once free-living bacteria.
2. Her theory provided evidence that eukaryotic cells evolved through a symbiotic relationship with prokaryotes.
3. She faced significant resistance initially but later gained widespread acceptance for her groundbreaking work.
4. The presence of their own DNA and double membranes in mitochondria and chloroplasts supports her theory.
5. Margulis' ideas have been foundational in the study of cellular evolution and modern cell biology.

Review Questions

• What does Lynn Margulis' endosymbiotic theory propose about the origin of mitochondria?
• How did Margulis' work change our understanding of eukaryotic cell evolution?
• What evidence supports the idea that mitochondria and chloroplasts were once independent prokaryotes?

Related terms

Endosymbiosis: A symbiotic relationship where one organism lives inside the other, crucial to Margulis' theory.

Mitochondria: Organelles known as the powerhouse of the cell, believed to have originated from proteobacteria.

Chloroplasts: Photosynthetic organelles found in plant cells, thought to have derived from cyanobacteria.