Inheritance

• in the nucleus of a typical human body cell there are 23 pairs of chromosomes
• we inherit one set of 23 chromosomes from each of out parents
• chromosomes are made from large molecule called DNA
  • DNA can replicate prior to cell division (mitosis or meiosis)
  • DNA code is used to synthesise proteins
• A gene is a small section of DNA
• Each gene codes for a particular combination of amino acids which make a specific protein
• these proteins determine our characteristics
• each gene may have different forms called alleles

• New body cells are produced:
  • when the animal is growing
  • to repair damaged tissues
  • to replace worn out tissue
• Mitosis occurs:
  • all of the chromosomes are replicated
  • the nucleus is divided in 2
• This results in two genetically identical cells
• Some cells undergo cell division again and again
• Some cells carry out their function then die

Asexual

• the cells of the offspring produced by asexual reproduction are produced by mitosis from the parental cells
• they contain the same genes as the parents