Cell structure and transport

• What are the two types of eukaryotic cells?

  Animal and plant
• What type of cell are bacteria?

  Prokaryotic
• Where is DNA found in animal and plant cells?

  The nucleus
• What is the function of the cell membrane?

  Controls movement of substances in and out
• What is the function of mitochondria?

  Releases energy through respiration
• What is the function of chloroplasts?

  Contain chlorophyll to absorb light energy
• What is the function of ribosomes?

  Site of protein synthesis
• What is the function of the cell wall?

  Strengthens the cell
• What is the structure of the main genetic material in a prokaryotic cell?

  Single loop of DNA
• How are electron microscopes different from light microscopes?

  Use beams of electrons instead of light
• What is the function of a red blood cell?

  Transports oxygen around the body
• Give three adaptations of a red blood cell.

  No nucleus, contains haemoglobin, bi-concave shape
• What is the function of a nerve cell?

  Carries electrical impulses around the body
• Give two adaptations of a nerve cell.

  Branched endings, myelin sheath
• What is the function of a sperm cell?

  Fertilises an ovum (egg)
• Give two adaptations of a sperm cell.

  Tail, contains lots of mitochondria
• What is the function of a palisade cell?

  Carries out photosynthesis in a leaf
• Give two adaptations of a palisade cell.

  Lots of chloroplasts, located at the top surface
• What is the function of a root hair cell?

  Absorbs minerals and water from the soil
• Give two adaptations of a root hair cell.

  Long projection, lots of mitochondria
• What is diffusion?

  Net movement of particles from high to low concentration
• Name three factors that affect the rate of diffusion.

  Concentration gradient, temperature, surface area
• What is osmosis?

  Diffusion of water through a partially permeable membrane
• Give one example of osmosis in a plant.

  Water moves from soil into root hair cell
• What is active transport?

  Movement of particles against a concentration gradient
• Why is active transport needed in plant roots?

  Mineral ions must move against the concentration gradient
• What is the purpose of active transport in the small intestine?

  Sugars can be absorbed when concentration is lower
• What are the characteristics of prokaryotic cells?

  Single-celled, no nucleus, smaller than eukaryotic
• What are the differences between light and electron microscopes?

  • Light microscopes use light to form images
  • Electron microscopes use beams of electrons
  • Light microscopes can view living samples
  • Electron microscopes cannot view living samples
  • Light microscopes are relatively cheap
  • Electron microscopes are expensive
  • Light microscopes have low magnification
  • Electron microscopes have high magnification
  • Light microscopes have low resolution
  • Electron microscopes have high resolution
• What are the definitions of diffusion, osmosis, and active transport?

  • Diffusion: Movement from high to low concentration
  • Osmosis: Diffusion of water through a membrane
  • Active transport: Movement against a concentration gradient using energy
• What are the adaptations of specialized cells?

  • Sperm cell: Tail, lots of mitochondria
  • Red blood cell: No nucleus, haemoglobin, bi-concave shape
  • Nerve cell: Branched endings, myelin sheath
  • Muscle cell: Protein fibers, lots of mitochondria
  • Root hair cell: Long projection, lots of mitochondria
  • Palisade cell: Lots of chloroplasts, top surface of leaf
• What are the functions of specialized cells?

  • Sperm cell: Fertilizes an ovum
  • Red blood cell: Transports oxygen
  • Nerve cell: Carries electrical impulses
  • Muscle cell: Allows movement
  • Root hair cell: Absorbs minerals and water
  • Palisade cell: Enables photosynthesis
• What is the jelly-like substance where chemical reactions happen in a cell?

  Cytoplasm
• What is the function of the permanent vacuole?

  Contains cell sap
• What is the role of plasmids in bacteria?

  Small rings of DNA
• What is the role of the flagellum in bacteria?

  Helps in movement
• What is the role of the cell wall in plant cells?

  Made of cellulose, strengthens the cell
• What is the role of chlorophyll in chloroplasts?

  Absorbs light energy for photosynthesis
• What is the role of ribosomes in a cell?

  Site of protein synthesis
• What is the role of the nucleus in a cell?

  Contains DNA