An Outline of the Cell Theory
2.1 Cell Theory
2.1.1 Outline the cell theory (2).
• All organisms are composed of one or more cells
• Cells are the smallest units of life
• All cells come from preexisting cells
• TOK: cell theory replaces the former ideas of spontaneous generation or abiogenesis in which inanimate matter assembles itself into living forms • Exception: muscle cells- more than 1 nucleus, very long; (fungal cells) hyphae roots- not a single unit; protoctista- not specialized to single function; subcellular things like organelles 2.1.2 Discuss the evidence for the cell theory (3).
• Robert Hooke first described cells in 1665 while observing cork with a microscope he built. Coined the term “cell” • Antoine van Leeuwenhoek …show more content…
• Retain ability to divide and differentiate into various cell types • Embryonic stem cells retain the ability to form any type of cell in an organism and can even form a complete organism • When stem cells divide to form a specific type of tissue, they also produce some cells that remain as stem cells. This allows for the continual production of a particular type of tissue. • Pluripotent- give rise to any type of cell
• Treating diseases?
2.1.10 Outline one therapeutic use of stem cells (2).
• Replace differentiated cells lost due to injury
• Therapeutic cloning- implanted stem cells replace lost cells • Tissue- specific stem cells- these cells reside in certain tissue types and can only produce new cells of that particular tissue • For example, stem cells have been introduced to humans to replace the damaged bone marrow of some leukemia patients • Bone marrow transplants are one of the many therapeutic uses of stem cells. Stem cells found in the bone marrow give rise to the red blood cells, white blood cells and platelets in the body. These stem cells can be used in bone marrow transplants to treat people who have certain types of cancer. • When a patient has cancer and is given high doses of chemotherapy, the chemotherapy kills the cancer cells but also the normal cells in the bone marrow. This means that the patient cannot produce blood cells. So before the