Biology Paper 1

• Nucleus

  • contains genetic materials
• Mitochondria

  • where most aerobic respiration happens
• Cytoplasm

  • where most chemical reactions happens
• Ribosomes

  • these are where proteins are made in the cell
• Cell wall

  • made of cellulose, it supports and strengthens the cell
• Permanent vacuole

  • contains cell saps
• Chloroplast

  • where photosynthesis happens
• Plasmid DNA


  a small commonly, circular section of DNA, that can replicate independently
• Chromosomal DNA

  • Bacteria don’t have a true nucleus
• Flagella

  • tail like structure that rotate to help bacteria to move
• Light microscopes

  • are used to look at larger sub cellular structures like the nucleus
• Electron microscopes

  • have a higher resolution and magnification, they are used to show smaller sub-cellular structures like ribosomes
• Equation

  • Magnification = image size / real size
• Required practical: MICROSCOPES

  • add a drop of water to the middle of a clean slide
  • cut up an onion and take off one layer
  • use tweezers to peel off some epidermal tissue from the bottom of the layer
  • using the tweezers, place the skin into the water on the slide
  • add a drop of iodine solution
  • place a cover slip on top
• Function of sperm cell

  • takes male DNA to the egg
• Adaptation of sperm cell

  • has a tail to help it swim to the egg
  • it’s has lot of mitochondria to provide energy for swimming
• Function of nerve cell

  • are long to cover more distance in the body
  • they have branches at the end to connect to other nerve cells
• Function of muscle cells

  • contract and relax muscles
• Adaptation of muscle cell

  • are long so they have space to contract
  • lots of mitochondria to provide energy for contracting
• Function of a root hair cell

  • absorbs water and minerals