Multiple & Missing Alleles Flashcards
What are the 4 blood types?
A
B
AB
O
What is blood type determined by?
Markers found on the outside of red blood cells
How many alleles does the gene that’s responsible for the markers in the ABO system have?
3
What are the 3 alleles that the gene that’s responsible for the markers in the ABO system called?
IA
IB
I*O
IO is what to IA and I*B ?
Recessive
What happens if a person has the genotype IA IB?
They show the effects of both alleles in the pheontype
What is it called when the alleles both affect the phenotype?
Codominant
What are sex linked genetic disorders?
Disorders that show a different pattern of inheritance in men
Compare the Y and X chromosome:
The Y sex chromosome is missing some genes found in the X chromosome which means that there will only be 1 allele for some genes on the X chromosome
The Y sex chromosome is missing some genes found in the X chromosome which means that there will only be 1 allele for some genes on the X chromosome. Why is this a problem?
If one of these X chromosome genes caused genetic disorders
How do sex linked genetic disorders affect men?
Men develop the disorder
How do sex linked genetic disorders affect women?
Can be carriers but don’t suffer from the disorder as her other X chromosome could be ‘healthy’
What is the genotype for colour blindness?
Homozygous recessive
What is haemoglobin responsible for?
Carrying oxygen around the body
What is haemoglobin made from?
4 polypeptides
What causes sickle disease?
When the polypeptide doesn’t fold correctly due to mutations in the genes which code for the production of the polypeptides that make up haemoglobin
What does a person experience when they have sickle cell disease?
A lot of pain, anaemia, at risk of other complications
What is thalassemia?
Red blood cells breaking apart can cause the person affected to experience shortness of breath
