Multiple alleles Flashcards
What is multiple alleles
When there are more than 2 alleles for the same gene
What is an example of multiple alleles
Fruitflies, they can have 4 different possible eye colours:
red, apricot, honey and white
How do we find whats dominant in multiple alleles
There is a hierarchy when multiple alleles exist
ex: Red eyes dominate all eyes
Apricot eyes dominate honey and white
Honey eyes dominate white
White eyes is recessive
The dominant allele in multuple alleles is represented as
Capital letters (ex: CC)
The next dominant alleles are represented as
Capital letters with a superscript
(Ex: Cᵖᵒ Cᵖᵒ and Cᵒ Cᵒ)
The recessive alleles are represented as
Lower case letter (ex: cc)
Do multiple alleles exist in humans
Yes
What is an example of multiple alleles in humans
Blood types
How many different alleles make up our blood types
3
What are the 3 different alleles that make up our blood types
- I ᵃ
- I ᵇ
- i
How many genotypes and phenotypes do the 3 different alleles make for our blood types
6 genotypes and 4 phenotypes
What do the alleles in our blood types control
The production of antigens on red blood cells
What is an antigen
A substance that makes the body produce anti-bodies against whatever substance has entered our body
What are anti-bodies
Proteins that help the body fight off viruses and bacteria
What antigen does allele Iᵃ produce
A
What antigen does allele Iᵇ produce
B
What antigen does allele i produce
No antigens
What are the 6 genotypes of our blood and the 4 phenotypes
- I ᵃ I ᵃ - Type A
- I ᵃ i -Type A
- I ᵇ I ᵇ -Type B
- I ᵇ i -Type B
- I ᵃ I ᵇ -Type AB
- ii -Type O
What blood types can type A blood recieve
A and O
What blood types can type B blood recieve
B and O
What blood types can type AB blood recieve
Every blood type
What blood type can type O blood recieve
Only type O
Why can certain blood types not give other blood types blood
Because those blood types have antibodies against them
Why can type AB blood recieve blood from everyone but can not give blood to anyone
Because type A and type B have antibodies against each other (type AB has both A and B) and type O cant recieve from anyone
Why can type O blood give blood to everyone
Because it produces no antigens, so it does not trigger an immune response from any blood types
What blood type is an example of co-dominance
Type AB, both antigens are present on the cell
A mother with type B blood gives birth to a child with type O blood and names a man with type O blood as the father. What is the genotype of the father and the child? what are the possible genotypes of the mother? Is the man a suspect? Why?
Genotype of father and child: ii
Genotype of mother: I ᵇI ᵇ or I ᵇi
The man is a suspect because 50% of the offspring can be type O
