Cell Specialisation

• As an organism develops, cells differentiate to form different types of cells
• Most types of animal cell differentiate at an early stage
• Many types of plant cells retain the ability to differentiate throughout life
• In mature animals cell division is mainly restricted to repair and replacement
• As a cell differentiates it acquires different sub-cellular structures to enable it to carry out a certain function and has become a specialised cell
• Sperm cells are specialised for reproduction

  • Its function is the deliver male DNA to female DNA
• Sperm cells have a long tail and streamlined head to help swim to the egg
• Sperm cells contain a lot of mitochondria to provide energy for the cell to swim to the egg
• Sperm cells carry enzymes in its head to digest through the egg cell membrane
• Nerve cells are specialised for rapid signalling

  • The function of nerve cells it to carry electrical signals from one part of the body to another
• Nerve cells are long to cover more distance and have branched connections at their ends to connect to other nerve cells and create a network throughout the body
• Muscle cells are specialised for contraction

  • The function of a muscle cell is to contract quickly
• Muscle cells are long so they have space to contract
• Muscle cells contain a lot of mitochondria to generate energy needed for contraction
• Root hair cells are specialised for absorbing water and minerals as they have a large surface area to increase rate of absorption
• The phloem is specialised at transporting food as it has very few subcellular structures so food can flow through
• The xylem are hollow to transport water
• The phloem and xylem form tubes and the cells are long and joined end to end to transport substances around plants