Life Processes and Evolution: Cells, Energy, and Taxonomy

Vocabulary flashcards covering organelles, energy, reproduction, homeostasis, and evolutionary taxonomy.

Mitochondrion

Organelle found in nearly all eukaryotic cells; produces ATP through cellular respiration.

Chloroplast

Organelle in plant cells that conducts photosynthesis; contains its own DNA.

Mitochondrial DNA

Circular DNA located in mitochondria; evidence for endosymbiotic origin.

Chloroplast DNA

DNA located in chloroplasts; supports endosymbiotic origin.

Endosymbiotic theory

Idea that mitochondria and chloroplasts originated as free-living bacteria engulfed by a host cell; supported by their DNA and ribosomes.

Rubisco

Enzyme that fixes CO2 by attaching it to an organic molecule during photosynthesis; uses ATP.

Carbon fixation

Process of converting inorganic CO2 into organic molecules, enabling sugar production; powered by ATP.

Autotroph

Organism that makes its own food using light or chemical energy (e.g., plants, algae).

Heterotroph

Organism that obtains energy by consuming other organisms (e.g., animals, fungi, many bacteria).

Photosynthesis

Process by which autotrophs convert light energy into chemical energy (glucose) using chloroplasts.

ATP

Adenosine triphosphate, the cell's energy currency; generated during respiration and photosynthesis.

Asexual reproduction

One parent; offspring genetically identical to the parent (e.g., bacteria, some plants).

Sexual reproduction

Two parents; offspring with genetic diversity due to combination of genes.

Homeostasis

Maintenance of internal balance despite external changes; example: normal body temperature around 37°C.

Tree of Life

Diagram of evolutionary relationships among all organisms; based on DNA comparisons.

DNA-based taxonomy

Classification of organisms based on similarities in DNA sequences.

Three domains of life

Bacteria, Archaea, and Eukarya—the highest-level grouping of life based on genetic data.

Common ancestor

All organisms share a common ancestor as revealed by DNA-based taxonomy.