Chromosomes, Genes & Proteins (CIE IGCSE Biology)

Inheritance of Chromosomes, Genes and DNA

• Inheritance is the transmission of genetic information from generation to generation
• Chromosomes are located in the nucleus of cells
• They are thread-like structures of DNA, carrying genetic information in the form of genes
• A gene is a short length of DNA found on a chromosome that codes for a specific protein
• This could be a structural protein such as collagen found in skin cells, an enzyme or a hormone
• Genes control our characteristics as they code for proteins that play important roles in what our cells do
• Think about zooming into the nucleus of a cell, as shown in the diagram below
  • On the right is the zoomed-out view
  • Which zooms in as we read across the diagram right-to-left

 

 Genes are short lengths of DNA that code for a protein. They are found on chromosomes

  

• Alleles are different versions of a particular gene. The ABO gene for blood group type has three alleles, I^A, I^B and I^O
• Alleles give all organisms their characteristics