Discovery of Cell and Cell Theory
Discovery of CellThe discovery of cells and advancement in its study is very closely related to the invention and modernization of microscope.Z. Jansen (1590) : invented microscopeGalileo (16...
Differences between Prokaryotic and Eukaryotic Cell
Prokaryotic and Eukaryotic cells
a. Prokaryotic cells (Pro: primitive; karyon: nucleus)
b. Eukaryotic cells (Eu: well; karyon: nucleus)
Differences between prokaryotic and eukaryotic cells
| Prokaryotic cells | Eukaryotic cells |
| Primitive cells found in bacteria and cyanobacteria. | Advanced cells found in Protista, Mycota, Plantae and Animalia. |
| Unicellular | Uni/multicellular |
| Comparatively small with average diameter 0.5-10 πm | Comparatively large with average diameter 10-100 πm |
| True nucleus absent. (Absence of nuclear membrane, nucleoplasm, chromatic fibers) | True nucleus present. (Presence of nuclear membrane, nucleoplasm, chromatic fibers) |
| DNA lies freely in cytoplasm known as incipient nucleus. | DNA lies inside the nucleus. |
| DNA is not associated with histone proteins. DNA is circular and naked. | DNA is linear and is associated to form histone proteins— chromatids. |
| Amount of DNA is low. | Amount of DNA is high. |
| They have single envelope system of organization. | They have double envelope system of organization. |
| Absence of membrane bound organelles like mitochondria, plastids, Golgi bodies, endoplasmic reticulum and lysosomes. | Presence of membrane bound organelles like mitochondria, plastids, Golgi bodies, endoplasmic reticulum and lysosomes. |
| Ribosome are of 70s type. | Cytoplasmic ribosome -- 80s Organelle ribosome -- 70s |
| Photosynthetic thylakoids lies freely in the cytoplasm. | Photosynthetic thylakoids are present inside the chloroplasts. |
| Mesosomes are the site of respiration and cytoplasmic membranes are in cyanobacteria. | Mitochondria are the sites of aerobic respiration. |
| Cell wall is made up of murein/peptidoglycan. | Cell wall is made up of cellulose (plant cell). |
| Flagella is present. simple lacking microtubules. | Flagella is present complex having 9+2 arrangement of microtubules. |
| Some have ability of nitrogen fixations. | None have ability of nitrogen fixation. |
| Cytoplasm doesn't show cyclosis. | Cytoplasm shows cyclosis. |
| Cell division occurs amitosis. | Cell division occurs by mitosis, meiosis, amitosis. |
| Endocytosis and exocytosis absent due to the presence of cell wall. | Endocytosis and exocytosis takes place in Protista and Animalia. |
| Sap vacuoles absent, gas vacuoles may occur. | Sap vacuoles occur in plant cells. |
