Biology paper 1

• What are the two types of microscopes?

  Light Microscope

  Electron Microscope
• What is the magnifying power of a light microscope?

  x 2,000
• What is the magnifying power of an electron microscope?

  x 2,000,000
• What is the resolving power?


  The ability to distinguish between two separate points
• What is the resolving power of light microscopes?

  200 nm
• What is the resolving power of electron microscopes?

  0.2 nm
• What are the advantages of light microscopes?

  1. living samples

  2. can view samples in colour
• What are the disadvantages of electron microscopes?

  1. dead samples

  2. samples in black and white
• What can they do with electron microscopes to make them coloured?

  Dye them or colour them in
• How do you work out magnification?

  Image size / Object size
• How do you work out image size?

  Magnification x Object size
• How do you work out object size?

  Image size / Magnification

  
• How do you convert cm to mm?

  x 10
• How do you convert um (micrometres) to mm?

  / 1000
• How do you convert mm to um (micrometres)?

  x 1000
• What does an animal cell contain?


  Cytoplasm, Nucleus, Ribosomes, Mitochondrion, Cell Membrane

  
• Where is the nucleus located in an animal cell?

  The centre
• What does the nucleus do?


  It controls the activities of the cell
• What is the role of the cytoplasm?

  Where chemical reactions take place
• Does an animal cell have a cell wall?

  No, it does not
• What is the role of the cell membrane?

  Controls the ENTRY and EXIT of SUBSTANCES inside the cell
• What is the role of mitochondria/on?

  Creates energy by aerobic respiration
• What does aerobic respiration mean?

  It requires oxygen
• What is the role of ribosomes?

  Where protein synthesis takes place
• What kind of shape is a plant cell?


  Rectangular
• What kind of shape is an animal cell?

  Circular
• What does a plant cell contain?

  Chloroplast

  Starch grain

  Cell Membrane

  Cell Wall

  Nucleus

  Mitochondrion

  Cytoplasm

  
• What is the role of the cell wall?

  Supports and protects the cell
• What is the role of the vacuole?

  contains cell sap
• Why is a plant cell rectangular?

  Due to the cell wall - strong
• Where is the nucleus placed in a plant cell?


  In one corner/side
• What is the role of chloroplasts?


  Full of a pigment called chlorophyll

  This is where photosynthesis takes place
• What are bacteria responsible for?

  Diseases such as tuberculosis, cholera.
• What does a bacterial cell contain?

  Pilli

  Plasmid

  Ribosomes

  Cytoplasm

  Plasma membrane

  Cell wall

  Capsule

  Bacterial Flagellum

  Nucleoid - circular DNA

  
• What is the purpose of a flagella to a bacterial cell?

  Helps it to move
• What is the crucial thing about a bacterial cell?

  There is no distinct nucleus - have nucleoid instead
• What is a plasmid?


  Genetic information
• What is the purpose of dendrites on a nerve cell?

  Allows the cells to make lots of connections with other cells

  
• Why do nerve cells have such a long axon?


  It forms the length of the neurone

  It carries the nerve impulse from one place to another
• Are nerve cells active?

  Yes, they are very active cells and need lots of energy