BIO111 #12-EukaryaEvolutionLectureNotes

Eukarya

A diverse group of organisms that includes unicellular and multicellular life forms, characterized by cells with a nucleus enclosed within membranes. Eukarya is one of the three domains of life, comprising kingdoms such as Animalia, Plantae, Fungi, and Protista, and is distinguished from Bacteria and Archaea by its complex cellular structure.

Endosymbiosis

A process in which one organism lives inside another; believed to explain the evolution of mitochondria and chloroplasts.

Mitochondria

Membrane-bound organelles involved in energy production, hypothesized to have evolved from α-proteobacteria through endosymbiosis.

Chloroplasts

Organelles that conduct photosynthesis, thought to have evolved through secondary endosymbiosis from cyanobacteria.

Infolding Hypothesis

The theory that the nuclear envelope and endomembrane system evolved from infoldings of the plasma membrane.

Cytoskeleton

A complex network of fibers within eukaryotic cells that helps maintain cell shape and is involved in cell movement.

Asexual Reproduction

Reproduction by mitosis in eukaryotes, resulting in offspring that are genetically identical to the parent.

Sexual Reproduction

Reproduction that involves the formation of gametes or spores through meiosis in eukaryotes.

Secondary Endosymbiosis

A process where a predatory protist engulfed a smaller, photosynthetic protist, leading to the formation of certain chloroplasts.

Lynn Margulis

A biologist known for her early hypothesis on endosymbiosis, which proposed the origin of eukaryotic cells.