biology gcse aqa combined

• CELL STRUCTURE P1 - what sub-cellular structures are within eukaryotic cells (animal cells)?

  cell membrane, cytoplasm, nucleus, mitochondria, ribosomes.
• CELL STRUCTURE P1 - what sub-cellular structures are within eukaryotic cells (plant cells)?

  cell membrane, cytoplasm, nucleus, cell wall, chloroplast, permanent vacuole, mitochondria, ribosomes.
• CELL STRUCTURE P1 - what is a prokaryotic cell?

  bacteria - no nucleus.
• CELL STRUCTURE P1 - what sub-cellular structures are within prokaryotic cells (bacteria) ?

  cell membrane, cytoplasm, cell wall, DNA free in the cytoplasm, plasmids.
• CELL STRUCTURE P1 - what is the function of the cell membrane?

  controls the movement of substances in and out of the cell.
• CELL STRUCTURE P1 - what is the function of the nucleus?

  contains DNA within the cell.
• CELL STRUCTURE P1 - what is the function of the mitochondria?

  where energy is released through respiration.
• CELL STRUCTURE P1 - what is the function of the ribosomes?

  site of protein synthesis.
• CELL STRUCTURE P1 - what is the function of the cytoplasm?

  jelly-like substance, where chemical reactions happen.
• CELL STRUCTURE P1 - what is the function of the perment vacuole?

  contains cell sap.
• CELL STRUCTURE P1 - what is the function of the chloroplast?


  contains chlorophyll to absorb light energy for photosynthesis.
• CELL STRUCTURE P1 - what is the function of the cell wall?

  made of cellulose, which strengthens the cell.
• CELL STRUCTURE P1 - what are plasmids?

  small rings of DNA within prokaryotic cells only.
• CELL STRUCTURE P1 - what is the function of the flagellum?

  allows the cells - bacterium to move (its tail).
• CELL STRUCTURE P1 - what is the function of a sperm cell?

  fertilises the egg.
• CELL STRUCTURE P1 - what are two adaptations of a sperm cell?

  tail to swim, contain lots of mitochondria to respire.
• CELL STRUCTURE P1 - what is the function of a red blood cell?

  carries oxygen around the body.
• CELL STRUCTURE P1 - what are three adaptions of a red blood cell?

  no nucleus, contains a red pigment called haemoglobin and has a bi-concave shape to increase surface area.
• CELL STRUCTURE P1 - what is the function of a nerve cell?

  carries electrical impulses around the body.
• CELL STRUCTURE P1 - what are two adaptations of a nerve cell?

  branched endings, myelin sheath insulates the axon.
• CELL STRUCTURE P1 - what is the function of a palisade cell?

  carries out photosynthesis in the leaf.
• CELL STRUCTURE P1 - what are two adaptions of a palisade cell?

  lots of chloroplasts, located at the top surface of the leaf.
• CELL STRUCTURE P1 - what is the function of a root hair cell?

  absorbs minerals and water from the soil.
• CELL STRUCTURE P1 - what are two adaptions of a root hair cell?

  long projection, lots of mitochondria.
• MICROSCOPES P1 - what are the connotations of a light microscope?

  uses light to form images, living samples can be viewed, relatively cheap, low magnification, low resolution.
• MICROSCOPES P1 - what are the connotations of an electron microscope?

  uses a beam of electrons to form images, samples cannot be living, expensive, high magnification, high resolution.
• MICROSCOPES P1 - what is the equation for magnification?


  Magnification = image size/ actual size. - remember I over AM.
• CELL TRANSPORT P1 - what is diffusion?

  the spreading out of particles from an area of high concentration to an area of low concentration.
• CELL TRANSPORT P1 - what is the movement of particles in diffusion like?

  particles move down the concentration gradient - from high to low concentration.
• CELL TRANSPORT P1 - is energy required in diffusion?

  no - it is a passive process.
• CELL TRANSPORT P1 - what are some examples of diffusion?

  humans - nutrients in the small intestine diffuse into the blood through villi. Fish - oxygen from water passing over the gills diffuses into the blood. plants - carbon dioxide used for photosynthesis diffuses into leaves through the stomata.
• CELL TRANSPORT P1 - name three factors that affect the rate of diffusion.

  concentration gradient, temperature and membrane surface area.
• CELL TRANSPORT P1 - what is osmosis?

  the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
• CELL TRANSPORT P1 - what is the movement of particles in osmosis like?

  water moves from an area of lower solute concentration to an area of higher solute concentration.
• CELL TRANSPORT P1 - is energy required in osmosis?

  no - its a passive process.
• CELL TRANSPORT P1 - what are some examples of osmosis?

  plants - water moves by osmosis from a dilute solution in the soil to a concentrated solution in the root hair cell.
• CELL TRANSPORT P1 - what is active transport?

  the movement of particles from a more dilute solution to a more concentrated solution using energy for respiration.
• CELL TRANSPORT P1 - what Is the movement of particles in active transport like?

  particles move against the concentration gradient - low to high concentration.
• CELL TRANSPORT P1 - is energy required in active transport?

  yes - using energy released during respiration.
• CELL TRANSPORT P1 - what are some examples of active transport?


  humans - active transport allows sugar molecules to be absorbed. plants - active transport is used to absorb mineral ions into the root hair cells from more dilute solutions in the soil.