No, an onion is not a living cell; it's a living organism composed of many cells.
Understanding the Onion's Structure
An onion is a plant, specifically a bulb. It's a complex structure made up of numerous individual plant cells working together. These cells, like all plant cells, contain a cell wall, cytoplasm, nucleus, and other organelles. Research using onion cells as a model system in plant cell biology is common, as seen in studies like the one using GFP imaging to visualize cellular dynamics (https://pubmed.ncbi.nlm.nih.gov/10376152/). Multiple sources, including this research on the dynamics of the endoplasmic reticulum in onion epidermal cells, highlight the use of onion cells in scientific investigations. This demonstrates that while an onion is not a single cell, it is a readily available and useful source of living plant cells for research purposes.
- Living Organism: An onion grows, reproduces (via seeds), and responds to its environment, all hallmarks of a living organism. (Flexi Says: Yes, an onion is a living thing. It is a type of plant that grows from a bulb. It has cells, can grow and reproduce, and responds to its environment, which are all characteristics of living organisms.)
- Cellular Composition: The onion bulb is made up of millions of individual plant cells. Even after slicing an onion, these cells remain—at least initially—viable and retain cellular activity (https://www.quora.com/If-you-slice-an-onion-will-there-still-be-living-cells-in-the-slices). Studies using onion cells, such as those involving microprojectile delivery of nucleic acids into intact plant cells (https://www.nature.com/articles/327070a0), further confirm the presence of living cells within the onion tissue.
- Model Organism for Cell Biology: The ease of accessing onion cells, along with their relatively large size and structure, makes them a common model organism for studying plant cell biology (https://ed.sc.gov/tests/tests-files/scpass-files/science-gr-7-performance-task-saline-and-cells-student-resource/).
