Inheritance, Gregor Mendel

Inheritance, Gregor Mendel

1. Stem cells

   • Unspecialised embryonic cells
   • Can be grown to replace tissuses, blood veins in the brain
   • Can be used to combat inherited conditions

2. Mendel

   • Worked out how characteristics were inherited
   • First to suggest seperately inherited characterisatics
   • Took along time for his ideas to be accepted
     • scientists didn't know about chromosomes and genes until after Mendel died.

3. Genes are found on chromosomes

   • Chromosomes are made from DNA which is a very long molecule with a double helix structire
   • Genes are short sections of DNA

4. everyone but identical twins have different genes

   • HUMANS have 23 pairs of chromosomes
     • 1 pair is the sex chromosomes
       • Females- XX
       • Males XY

5. Alleles

   • Dominant- masks the effect of another
   • Recessive- effect is masked by that of anothers
   • PHenotype- PHysical apperarance
     • Genotype- the Genetic make up- which alleles does the individual inhreit
   • Hetrozygous- same alleles eg. DD or dd
     • Homozygous- two different alleles eg. Dd or dD

6. Inherited diseases

   • cystic fibrosis
     • caused by a recessive allele
       • this means the allele must be inherited from both parents
     • Can be passed on passed on from 2 parents who don't have it themselves as they could be carriers