Cheek cells are eukaryotic cells (cells that contain a nucleus and other organelles within enclosed in a membrane) that are easily shed from the mouth lining.

Plant and animal cells are eukaryotic, meaning that they have nuclei. Eukaryotic cells are found in plants, animals, fungi, and protists. Eukaryotic cells are typically larger than prokaryotic cells, ranging from around 10 to 100 μm in diameter.

: of, relating to, or being a typically unicellular organism (as of the domains Bacteria and Archaea) lacking a distinct nucleus and membrane-bound organelles : being or characteristic of a prokaryote prokaryotic genes prokaryotic microorganisms.

Figure 1.8. Evolution of cells. Present-day cells evolved from a common prokaryotic ancestor along three lines of descent, giving rise to archaebacteria, eubacteria, and eukaryotes. Mitochondria and chloroplasts originated from the endosymbiotic association of aerobic (more…)

Organelles are the substructures (such as mitochondria and chloroplasts) inside cells that perform particular functions. They are therefore smaller than cells. They are therefore larger than cells.

Defining cells of living creatures Cells are sacs of fluid surrounded by cell membranes. Inside the fluid float chemicals and organelles. An organism contains parts that are smaller than a cell, but the cell is the smallest part of the organism that retains characteristics of the entire organism.

The DNA molecules contains thousands of genes which is located inside chromosomes. Therefore, gene is smaller than DNA.

Quarks have an astonishingly wide range of masses. According to their results, the up quark weighs approximately 2 mega electron volts (MeV), which is a unit of energy, the down quark weighs approximately 4.8 MeV, and the strange quark weighs in at about 92 MeV.