GCSE BIOLOGY

• 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 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 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.
• 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 - is energy required in diffusion?

  no - it is a passive process.
• 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 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.
• CELL DIVISION P1 - what do body cells divide to form?

  two identical daughter cells by going through the cell cycle.
• CELL DIVISION P1 - what is a stem cell?

  an undifferentiated cell that can develop into one or more types of specialised cell.
• CELL DIVISION P1 - what are the three types of stem cell?

  embryonic, adult stem cells and plant meristem.
• CELL DIVISION P1 - where is the adult stem cell found?

  bone marrow.
• CELL DIVISION P1 - what are the advantages of using adult stem cells?

  fewer ethical issues, relatively safe.
• CELL DIVISION P1 - what are disadvantages of using adult stem cells?

  requires a donor, can only differentiate into certain types of specialised cells.
• CELL DIVISION P1 - what are the advantages of using embryonic stem cells?

  can treat a wide range of diseases, may be possible to grow whole replacement organs, usually no donor needed.
• CELL DIVISION P1 - where are plant meristems found?

  meristem regions within the roots and shoots of plants.
• CELL DIVISION P1 - what can plant meristems differentiate into?


  can differentiate into any type of cell.
• CELL DIVISION P1 - what are the advantages of using plant meristems?

  rare species of plants can be cloned to prevent extinction, plants with desirable traits can be cloned, fast and low cost production of large numbers of plants.
• CELL DIVISION P1 - what are the disadvantages of using plant meristems?

  cloned plants are genetically identical, so a whole crop is at risk of being destroyed by a single disease.
• ORGANISATION IN ANIMALS P1 - what is the order smallest to largest of cells in the body?

  cells, tissues, organs, organ systems, organisms.
• ORGANISATION IN ANIMALS P1 - what are the 11 things that make up the human digestive system?

  mouth, salivary glands, oesophagus, stomach, liver, pancreas, gall bladder, small intestine, large intestine, rectum and anus.
• ORGANISATION IN ANIMALS P1 - what happens to the air when breathing?

  1. air moves into the body through the mouth and nose. 2. down the trachea. 3. into the bronchi. 4. through the bronchioles. 5. into the alveoli (air sacs). 6. oxygen then diffuses into the blood in the network of capillaries over the surface of the alveoli.
• ORGANISATION IN ANIMALS P1 - what is the function of an artery?

  carries blood away from the heart, high pressure.