This question is sound really funny to me. its like some maths formula question.
its actually my parents. mum O+ and dad A+
total of 4 kids. 1st: A- 2nd:A+ 3rd: O- (thats me) and 4th: O+
spreads out nicely like a report card.
does such cases a norm?
2007-01-05 01:31:29 · 9 answers · asked by rachrach84 1 in Science & Mathematics ➔ Biology
Simple genetics.
For any given trait, we inherit one gene from mom and one from dad. If someone has a Rh+ gene from one parent and a Rh- gene from the other, then the dominant gene prevails. Rh+ is a dominant trait, so the individual would be Rh+.
Evidently, both of your parents have one Rh+ gene and one Rh- gene. By random chance, you happened to get the Rh- gene from both of your parents. That makes you Rh-.
2007-01-05 01:41:53 · answer #1 · answered by Bramblyspam 7 · 0⤊ 0⤋
Rh positive means that the Rh factor is there. All traits are cotrolled by a gene from mom and dad. Th nes result from the combination of genes that were both negative(or in the case of Rh missing) So the O+ was only positive on one of the 2 genes that make it up for Rh so 1/2 the eggs would lack the trait. With A+ also, the trait was only there one of the two genes, so half of the sperm did not carry the Rh factor. Therefore half + and half - is just right. The 4 children show all the possible combinations of the A, O, +, -. Perfect distribution.
2007-01-05 01:46:01 · answer #2 · answered by science teacher 7 · 0⤊ 0⤋
Well, Rh + is a dominate characteristic, so your mom & dad both have a gene for Rh + and a no Rh gene. You & your sibs that are Rh - had to get no Rh genes from both parents. While the chances are more like 3 + to 1 -, it's quite possible to get the 50/50 of your family. That’s way simplified – Wikipedia gives a more complete answer at the link below.
2007-01-05 01:48:26 · answer #3 · answered by Celt 3 · 0⤊ 0⤋
The reason a parents with positive can have negative kids is very simple. Positive blood type is a dominate trait so if you have the alleles Rh+ Rh+, or Rh+ Rh-, but since negative blood type is recessive you can only get it if you have the alleles Rh- Rh-. So to have a negative blood type both your parents have the alleles Rh+ Rh- and both passed on the Rh- to the kid making him Rh- Rh-. The answer to your other question is no. Genetics is random, probability says that should happen but your parents could of have 50 kids all with O-. Is it norm though that is tough to say all I can say is that probability would put that as norm but probability is not all was right.
2007-01-05 01:43:52 · answer #4 · answered by trollbrawler27 2 · 0⤊ 0⤋
The Rh+ is a dominant trait, meaning you are Rh+ as long as you have one of Rh+ of the 2 alleles that express it. The Rh- trait is a recesive inherited, meaning you need to have both of Rh- alleles to be Rh-. You can be Rh+ but a carrier of (non-expressed) gene of Rh-. When 2 individuals, both carriers of Rh- have a child there are 25% chances to get a child with Rh- (he has both Rh- alleles).
Exemple:
There are Rh+ people having [Rh+ Rh+] or [Rh+ Rh-] pairs
and Rh- people have [Rh- Rh-] pair.
Your parents have both [Rh+ Rh-] pair.
2007-01-05 01:46:39 · answer #5 · answered by qflowers 1 · 0⤊ 0⤋
it is conceivable, yet no longer likely. the mum and dad are Rh-, so as that they are in a position to have little ones that are Rh-. it is conceivable that a mutation interior the germ cells (sperm or egg) would have befell and the resultant baby be Rh+, yet it is uncommon. The genotypes of the mum and dad are: O- O- x O- O- So, their little ones can in uncomplicated terms be: O- O- different than for the uncommon undertaking of a germ cellular mutation being surpassed on.
2016-10-06 11:43:31 · answer #6 · answered by ? 4 · 0⤊ 0⤋
Both mom and dad are heterozygous for D (Rh) - their genotype is Dd. There is a 25% chance that any child would be Rh neg (dd).
2007-01-05 04:12:57 · answer #7 · answered by <3 Chrissy 4 · 0⤊ 0⤋
Biology and Maths are not alike, a couple where both are positive can have negative blood type in their children for the other types of blood in the family members.
2007-01-05 01:40:06 · answer #8 · answered by Angela Vicario 6 · 0⤊ 2⤋
Yes with heterozygous parents.
2007-01-05 02:32:40 · answer #9 · answered by Anonymous · 0⤊ 0⤋