cell differentiation and specialisation

• cells ... to become ...

  differentiate, specialised
• differentiation


  the process in which cells become specialized in structure and function
• specialisation


  the adaptation of an organism or organ to a special function or environment
• most differentiation occurs as...

  an organism develops
• in most animal cells, the ability to differentiate is...


  lost at an early stage
• in most plant cells, the ability to differentiate is...


  never lost
• undifferentiated cells are called...

  stem cells
• what are sperm cells specialised for?

  reproduction
• sperm cell diagram

  
• function of a sperm cell

  to get the male DNA to the female DNA
• sperm cell specialisation


  - long tail and streamlined head to help it swim to the egg

  - lots of mitochondria to provide energy

  - carries enzymes in its head to digest through the egg cell membrane
• what are nerve cells specialised for?

  rapid signalling
• nerve cell diagram

  
• function of a nerve cell

  to carry electrical signals from one part of the body to another
• nerve cell specialisation


  - long to cover more distance

  - branched connections at their ends to connect with other nerve cells ad form a network throughout the body
• what are muscle cells specialised for?

  contraction
• muscle cell diagram

  
• function of a muscle cell


  contract and relax quickly to allow movement
• muscle cell specialisation


  - long, giving them space to contract

  - lots of mitochondria to give them the energy for contraction

  - lots of protein that provide the structure and strength muscles need for contraction
• what are root hair cells specialised for?

  absorbing water and minerals
• root hair cell diagram

  
• function of root hair cells

  absorption of water and mineral ions from soil
• root hair cell specialisation

  - large surface area to maximise absorption

  - lots of mitochondria to prove the energy needed in active transport of minerals in the soil
• what are phloem cells specialised for?


  to transport food products to parts of the plant where they are needed
• phloem cell diagram

  
• phloem cell function


  they transport sugars, amino acids, other substances both up and down the stem to leaves, flowers and roots
• phloem cell specialisation


  - pores/sieves in the end walls for cell sap to flow through

  - companion cells attached to each cell to provide energy for transportation
• what are xylem cells specialised for?

  to transport water and mineral ions up the plant from the roots to the leaves
• xylem cell diagram

  
• xylem cell function


  conveys water and dissolved minerals from the roots to the rest of the plant and also provides physical support for the stem
• xylem cell specialisation


  - hollow tubes made of dead cells supported by lignin to strengthen the stem

  - end walls of the cells are broken to allow water to move through
• what are red blood cells specialised for?

  transporting and carrying oxygen around the body
• red blood cell diagram

  
• red blood cell function

  to carry oxygenated blood from the lungs around the body and carry deoxygenated blood back to the lungs
• how are red blood cells specialised?

  - small and flexible to fit through narrow vessels

  - biconcave shape that maximises surface area to absorb oxygen

  - no nucleus provides more space for haemoglobin

  - contains haemoglobin which binds to oxygen
• embryonic stem cells can...

  turn into any type of cell
• undifferentiated cell


  Immature cell that has not yet acquired special structure or function; for example a stem cell
• differentiated cell


  a cell that has become specialized to perform a particular function
• stem cell


  unspecialized cell that can develop into a specialized cell under the right conditions
• where are stem cells found

  in early human embryos or the bone marrow of adults (adult stem cells)