What determines whether certain blood types are positive or negative?

Question

When I learned about blood-typing in 9th grade biology, nothing was said about "positive" or "negative".

Answer 1

One of the main factors which determine blood type is family genetics. A child receives separate sources of genetic code called alleles from each parent at the time of conception.

One of the alleles located on chromosome 9 contains the precise blood type of the donor parent, and is classified as A, B, AB or O.

An additional factor is called the Rhesus factor, which could be positive or negative.

The actual blood type of a child is determined by the dominant blood type between the two parents. A and B are both dominant over O, which means a child that receives an A blood type from the father and an O blood type from the mother will have an A blood type.

Answer 2

If either of your parents have a negative (rh) factor, than it is possible for you to be (rh)-. If they are both positive, then you will be positive. If they are both (rh)-, then you will be (rh)-. The (rh) factor is separate from the blood type, meaning you can have a blood type of O, A, B or AB and be either positive or negative. I am A-. My oldest son is O- (his father was O+). My husband is B+. My youngest son ended up being AB-. The majority of the population is positive. Hope my example helps you some.

Answer 3

it's a gene present or absent from the cells. it's called Rh after rhenius monkies. so you're eaither rh (+) or (-); it was discovered while doing studies for why people who recieved blood still have a transfusion reaction.

a person with the rh gene can get rh negitave blood transfuion. (since the gene is not there, there nothing to react on)

Answer 4

rh factor

Answer 5

Then presence (+ve) or absence (-ve) of the rhesus factor.

Individuals either have, or do not have, the Rhesus factor (or Rh D antigen) on the surface of their red blood cells. This is usually indicated by 'RhD positive' (does have the RhD antigen) or 'RhD negative' (does not have the antigen) suffix to the ABO blood type.