https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:cells-and-organisms/x0c5bb03129646fd6:cells-organisms/v/ms-cells-and-organisms 2022-09-10T03:04:58.582913383Z Cells and organisms All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular). Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/4c87c6c9-4669-4319-91b7-935603e64401_1280_720_base.png Cells and organisms All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular). https://cdn.kastatic.org/ka-youtube-converted/Uiqro5TUyLA.mp4/Uiqro5TUyLA.mp4 237 Cell: The Basic unit of life https://www.khanacademy.org/science/up-science-grade-6-revision-course-full-term/x017c12e57b64cfa8:week-2/x017c12e57b64cfa8:untitled-216/e/cells 2025-08-04T12:23:36.052124233Z Cells Let's do some questions vibhor exercise https://www.khanacademy.org/science/revision-term-2-tg-biology-class-8/x04828215b460a495:week-2/x04828215b460a495:cell-the-basic-unit-of-life/v/cell-parts-and-their-functions-in 2025-06-11T14:40:49.43988516Z Cell parts and their functions Let's understand cell and their functions! Dubverse video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Cell parts and their functions Let's understand cell and their functions! https://cdn.kastatic.org/ka-youtube-converted/8Rg1tUWmlL0.mp4/8Rg1tUWmlL0.mp4 253 Cell: The Basic unit of life https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/cell-structures-and-their-functions/e/cell-structures-and-their-functions-exercise 2026-04-05T18:28:15.377289243Z Cell structures and their functions Test your knowledge of cell structures and their functions! Ashley Mucha exercise https://www.khanacademy.org/science/revision-term-2-tg-biology-class-8/x04828215b460a495:week-2/x04828215b460a495:cell-the-basic-unit-of-life/v/scale-of-cells-dubv 2025-05-29T08:44:44.739717086Z Scale of cells Even though molecules, proteins, viruses, and cells are all tiny, there are significant size differences between them. The diameter of a water molecule is roughly 0.28 nanometers. The diameter of the protein hemoglobin is roughly 5 nanometers. The diameter of the HIV virus is roughly 120 nanometers. A red blood cell is 6-8 micrometers. Let's learn more about the scale of cells in this video. Dubverse video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Scale of cells Even though molecules, proteins, viruses, and cells are all tiny, there are significant size differences between them. The diameter of a water molecule is roughly 0.28 nanometers. The diameter of the protein hemoglobin is roughly 5 nanometers. The diameter of the HIV virus is roughly 120 nanometers. A red blood cell is 6-8 micrometers. Let's learn more about the scale of cells in this video. https://cdn.kastatic.org/ka-youtube-converted/e762tUv7sT8.mp4/e762tUv7sT8.mp4 439 Cell: The Basic unit of life https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/cell-size/e/cell-size-exercise 2026-04-08T08:09:55.69362548Z Cell size Test your knowledge of cell size! Haider Ali Bhatti exercise