Chromosomes

• What are chromosomes made up of?


  DNA and proteins
• What is a gene?


  A section of DNA which codes for protein
• How many chromosomes are found in the nucleus of human body cells?


  46
• How many chromosomes are found in the nucleus of gametes?


  23
• How are chromosomes arranged in the nucleus of a body cell?


  Arranged in pairs (46 chromosomes)

  form 23 pairs.
• What are organisms primarily made up of?

  Cells
• What is the main purpose of microscopes in biology?

  To study cells in detail
• What type of microscope is commonly used in schools?

  • Compound microscope
  • Uses two lenses: objective and eyepiece
• How do light microscopes magnify images?

  By using two lenses to enlarge specimens
• What is the size range of animal cells?

  0.01 mm – 0.05 mm
• What is the size range of plant cells?

  0.01 mm – 0.10 mm
• What is the minimum size the human eye can see?

  About 0.05 mm
• What does the term 'magnification' refer to in microscopy?

  The scaling up of an image viewed
• What are the two lenses in a compound microscope?

  Objective lens and eyepiece
• How does the objective lens function in a compound microscope?

  It produces a greatly magnified image
• What is the role of the eyepiece in a compound microscope?

  To further magnify the image produced
• How is the magnification of a microscope calculated?

  • Magnification = magnification of eyepiece × magnification of objective
  • Example: If eyepiece is ×10 and objective is ×4, then total magnification is ×40
• If the magnification of an eyepiece is ×10 and the objective is ×40, what is the total magnification?

  ×400
• What is the function of a microscope in biology?

  • To magnify biological specimens
  • To allow detailed examination of cells