specialised cells

• sperm cells are specialised cells

  • flagellum to swim to the egg
  • acrosome in the head which contains the digestive enzyme needed to penetrate the egg
• The head of the sperm

  • contains nucleus , carries half of an organisms genetic material which combines with the the eggs half of genetic material
  • acrosome containing digestive enzyme needed to penetrate the egg
• nerve cells are specialised to send electrical messages around the body
• Root hair cells are specialised for absorbing water and minerals from the soil
• Root hair cells are located underground near the roots so contain no chloroplasts for photosynthesis
• Root hair cells have long projections to increase the surface area and absorb more water
• Xylem cell is specialised to transport water up the stem of the plant and into the leaves
• xylem vessels are open ended to allow water to move through

  
• the lignin is a xylem cell strengthens the cell wall

  
• phloem transports sugars made by photosynthesis around the plant
• Red blood cells

  1. contain haemoglobin which carries oxygen molecules
  2. dont have a nucleus , allows more space to carry oxygen
  3. flat disc shape = large surface area allows them to absorb oxygen as best as possible
• sperm cell

  1. tail to move them towards the egg
  2. many mitochondria allowing them to respire and have lots of energy
  3. acrosome ( head of the sperm ) contains enzymes that digest the egg
• Nerve cell

  1. thin and long, meaning they can quickly carry messages over large distances
  2. branched connections at each end allowing them to send signals to other parts of the body
  3. fatty sheath around them increasing the speed that the message can travel
• Villi

  1. large surface area
  2. thin walls to absorb
  3. tiny hairs to absorb more food and water
• root hair cells

  1. large surface area for water absorption
  2. tiny hairs to poke into the soil
• palisade cells

  1. lots of chloroplast for photosynthesis
  2. near the top of the plant where most light is
• Xylem

  1. transport water from the roots
  2. xylem cells die and their ends break down allowing them to form long tubes that allow water through / hollow ended
  3. thick walls to support the plant
• phloem

  1. transport sugary water from the leaves to the rest of the plant
  2. phloem cells are alive ( unlike xylem cells)
  3. many mitochondria allowing lots of energy for glucose to transport sugars through the phloem