IF father is A+ and mother is A-, then what are the possible blood group of the child for these parents?

Answer 1

Unfortunately Ruth does not know what she is talking about.
As far as the ABO system goes the parents could have a genotype of AA or AO (they could have one gene for the A blood group antigen or two, we all have two sets of genes for everything, O means no antigen). Thus the possible combinations are:
Both parents AA (25%). The children would all be A group.
Both parents AO (25%). The children could be AA (25%), AO (50%) or OO (25%). Therefore with this combination the probability of the child having blood group A is 75% while there is a 25% chance of having blood group O.
One parent AO and the other AA (50%). The chances are 50% that the child would be AA and 50% that it would be AO. In either case the blood group would be A.
Thus the overall probability of having a child with blood group O would be 25% of 25% which is 6.25%.
As far as the Rh system is concerned, the mother is -/- (she does not have the gene for the Rh antigen. The father could be either +/+ or +/-.
The child would never get the gene for the Rh antigen from the mother. The chances of getting the gene from the father are at least 50%. So the children have at least a 50% chance of being Rh +ve.
So in simple terms the probabilities for the various possible blood groups would be:
A+ve 46.8%, A-ve 46.8%, O+ve 3.1% and O-ve 3.1%.
Sorry for the long winded explanation but I thought I had to explain my figures to convince you.

Answer 2

As far as the Rh factor ( - or +) it can be difficult to determine but, the blood type would definitely be Type A. The Rhesus Factor(Rh) is either negative or positive. We all inherit a set of three Rh genes from each parent that is called a " haplotype". We inherit either a positive or negative gene from each parent. This means that we then possess two of each gene and is then passed on to the infant. If a person is Rh+, their blood is said to contain the factor. If they are negative, it does not contain the Rh factor. It is possible to have a Rh- child if the mother is Rh- and the father is Rh+. It basically, depends on the genes that each parent carries. Sorry for the length of my answer.I hope that this helps. Here's a web:
http://www.childbirthsolutions.com/articles/preconception/rhesus/index.php

Answer 3

My parent's had 4 children. My Dad was AB+ and my Mom A- three of us children are A+ and 1 is A-