Biology

• What is the gas that passes out of the blood in the alveoli
• What is the gas that passes out of the blood into the alveolus
• The lungs are adapted for efficient gas exchange
• Root hair cell


  • Specialised for its function
  • Has a large surface area to absorb a lot of water and minerals
• Root hair cells do not contain chloroplasts and do not photosynthesize
• Changing the intensity of light reaching the pondweed

  1. Use a lamp as a light source

  2. Move the pondweed towards or away from the light
• Pondweed light intensity


  Affects the rate of photosynthesis
• Other factors affecting photosynthesis rate include temperature and carbon dioxide concentration
• Low power objective lens


  • Provides the largest field of view
  • Should not be moved towards the slide to avoid damage
• Levels of biological organisation


  • Smallest - Molecule
  • Cell
  • Tissue
  • Organ - Largest
• Vaccines


  Make people immune to a disease
• Ways to control malaria

  • Insect repellent
  • Mosquito nets
  • Long clothing
  • Anti-malaria tablets
  • Kill mosquitoes
• Mitochondria produce energy through respiration.
• The nucleus is the control centre of the cell, containing DNA.
• Chromosomes are made up of genes that determine characteristics such as eye colour or height.
• Cell membranes regulate what enters and exits cells.
• RNA stands for ribonucleic acid.
• Ribosomes synthesize proteins from amino acids.
• Ribosomes synthesise proteins from amino acids.
• Oxygen


  Gas produced by pond weed in the light