Genetics

DNA carries the genetic code which determines the characteristics of a living thing.
Genes are sections of DNA which code for a specific protein by specifying the order of the
amino acids are joined together.
Chromosomes contain DNA
Alleles are different forms of the same genes e.g. you can have…

Process:
­ Firstly the cell replicates its DNA to form X shaped chromosomes. (each arm is
identical)
­ The chromosomes line up in the centre of the cell and are pulled apart by cell fibres
­ This causes one arm of the X shaped chromosome to go to one half…

Chest infections
Coughing and wheezing

The allele for the disease is recessive and so both parents need to have the disease/be
carriers of the disease for it to have a chance of showing up in the offspring. Parents can be
carriers of cystic fibrosis and not actually have it as…

H h
h Hh hh
h Hh hh

The genetic diagram shows there is a 50% chance of the offspring having Huntington's if just
one parent is a carrier of the disease. There is also 50% chance that they will not have the
disease. As Huntington's is caused by a…

A a
A AA Aa
a Aa aa

From the genetic diagram we can see that there is only a 25% chance of the offspring
developing sickle cell anaemia, 50% chance of the offspring being carriers and 25%chance
of not having the disease/not being a carier.

























Differentiation is where cells…

bone cells lost in your leg in order to repair it. However there are only a limited number of adult
stem cells in the body so e.g. if you have an accident and injure your brain severely there
aren't enough stem cells in the brain to turn into brain cells…

Can wipe out certain genetic disorders

During processes like IVF most of the
embryos are destroyed anyway this just
helps identify the healthy ones to keep

Treating disorders requires a lot of the
tax payers/ government money






When asked to evaluate need to give reasons for against and a conclusion.…

­ Invasion of privacy as details can be stored and kept




































Gregor Mendel was an Austrian monk. He cross breaded pea plants that were tall with small
ones. He expected to find a medium sized offspring but instead found a tall plant. He reached
3 important conclusions

1)Characteristics in plants…

However in Mendel's time his work was not accepted as no one knew anything of genes/DNA
etc., he was not considered a real scientist , other theories were accepted at the time and not
many scientists knew of him