Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: Stem cells and differentiation

Questions and Answers List

level questions: Stem cells and differentiation

QuestionAnswer
Define stem cellsunspecialised cells, that can develop into different types of cells
Define differentiationthe process by which a cell becomes specialised for its job
Where can you find adult stem cells- in the bone marrow - here they divide and differentiate to replace worn out blood cells (erythrocytes and neutrophils)
What can you find in embryosStem cells that can develop into any type of human cell
What do adult stem cells dothey replace damaged cells
Where can you find stem cells in plantsin the meristems, where they divide and differentiate into xylem vessels and phloem sieve tubes.
How can stem cells be used to cure diseases such as Parkinson's- the disease causes the loss of a particular type of nerve cell found in the brain - these cells release a chemical called dopamine, which is needed to control movement - transplanted stem cells may help to regenerate the dopamine producing cells
What are erythrocytes- they are red blood cells that carry oxygen in the blood - they have a biconcave disc shape which provides a large surface area for gas exchange - they have no nucleus so there's more room for haemoglobin
What are neutrophils- a type of white blood cell - their flexible shape allows them to engulf foreign particles or pathogens - their cytoplasm contains many lysosomes to break down engulfed particles
What are epithelial cells- cells that cover the surface of organs - the cells are joined by interlinkingg cell membranes and a membrane at their base
What are sperm cells- male sex cells - they have a flagellum so they can swim to the egg - they have lots of mitochondria to provide energy to swim - the acrosome contains digestive enzymes to enable the sperm to penetrate the surface of the egg
What are palisade cells- cells in the leaves - does most of the photosynthesis - they contain many chloroplasts, so they can absorb a lot of sunlight - the walls are thin, so carbon dioxide can easily diffuse into the cell
What are guard cells- cells found in pairs, with a gap between them to form a stomata