Inheritance, Variation and Evolution

• Asexual and sexual reproduction: Genes are ?

  Section of DNA which code for the production of a protein
• Genome 


  all the genetic material in an organism .
• DNA is stored in?

  DNA is stored in Chromosomes in the Nucleus.
• DNA

  A double stranded polymer stored in the Chromosomes of a Nucleus.
• Polymers 


  Long Chains of Phosphates and Sugars.
• DNA contains the code to produce what ?

  Proteins
• Protein


  A polymer of amino acids
• Gene 


  A Small Section of DNA which codes for a particular protein
• Allele


  Different Versions of the same gene.
• Punnet square 


  Shows the SImple patterns of inheritance where a characteristic is controlled by a single gene .
• Heterozygous


  Different Alleles on both sets of Chromosomes.
• Homozygous


  Same Alleles on both sets of Chromosomes.
• The carrier has :

  1. heterozygous
  2. carry the allele for a certain trait
  3. recessive allele
• Cystic fibrosis symptoms

  1. thick mucus on lungs which means a blocked air passage
  2. prone to infection
  3. mucus in pancreas affect digestion of food
• cystic fibrosis is caused by

  A recessive Allele
• Dominant allele 


  Shows the Characteristics in the living thing
• Recessive Allele 


  The characteristic can only be seen if we inherit it from both parents.
• Recessive alleles are what letters 


  Lower case letters
• Dominant alleles are what letters 


  Upper case letters
• Cystic fibrosis is caused by

  A recessive allele .
• Sufferer of Cystic fibrosis must be

  Homozygous ( ff)
• Genotype 


  The genetic make-up
• Phenotype


  The Physical form
• Polydactyly 


  caused by a dominant allele
• If you have polydactyly, Why can you not be the carrier?

  you have a Physical implication.
• Mitosis


  1 parent cell splits into 2 identical daughter cells.
• what is Mitosis used for ?

  Growth and repair
• Meiosis


  Form of cell division which produces four non-identical haploid cells or gametes
• What is meiosis used for ?


  used in the production of a gamete
• features of mitosis

  1. 2 daughter cells
  2. genetically identical
  3. daughter cells have 46 chromosomes
  4. zygote-divide to make embryos
  5. growth and repair
• Features of Meiosis

  1. produces gametes (sex cells )
  2. occurs in the reproductive organs
  3. gametes have 23 Chromosomes (always halved )
  4. 1 cell has 4 gametes
  5. gametes are genetically different