Cell Structure

The location of DNA

A cell is a self-contained element within an organ of an organism.

Within the cell wall are a variety of parts.

"Each (eukaryotic) cell has

• a nucleus,
• many mitochondria, photosynthesising chloroplasts (if it is from a green plant),
• numerous small vesicles, and
• complex networks of internal membranes studded with tiny particles forming elegant rosette-like patterns.."(1)

Each part has a different function, and the cell contains DNA of two kinds.

• The mitochondria contain DNA. Mitochondria are passed from mother to offspring. They come as part of the egg cell, and therefore a mother's mitochondria are identical to her daughter's and her son's. Mitochondria DNA does not change during the process of reproduction. Mitochondria are responsible for the energy production of the cell.
• The other sort of DNA contained within a cell is in the nucleus. This nuclear DNA ordered as genes, within chromosomes, regulates the inherited characteristics of the plant or animal of which it is a part.

(1) Lifelines, Biology, Freedom and Determinism, copyright (c) Steven Rose 1997, Allen Lane Penguin Press, ISBN 0-713-99157-7

Determinism?
"Humans are not empty organisms, free spirits constrained only by the limits of our imaginations. Nor are we reducible to "nothing but" machines for the replication of our DNA. We are rather, the product of the constant dialectic between "the biological" and "the social" through which humans have evolved, history has been made and we as individuals have been developed."

(1) Lifelines, Biology, Freedom and Determinism, copyright (c) Steven Rose 1997, Allen Lane Penguin Press, ISBN 0-713-99157-7