A DNA question. Am I correct in thinking that in a family who produced one female child, the male DNA is lost

Question

And am I correct in thinking that female DNA is constant?

Yes, but wouldn't the original male DNA in the female, be diluted futher down th line

A lot of very interesting answers! My question arises from passages in 'The DaVinci Code', where its claimed that Mary Magdalene is 'The Holy Grail' because she holds the blood-line of Jesus, through their daughter, Sarah. Some answers seem plausable ie. the DNA [blood-line] is diluted through matings in further generations. In this case I would conclude that there is no 'pure lineage' from Jesus, in this case Anyone in agreement?

Answer 1

i would think so it's like half and half for example my dad didn't have any sons he had 3 daughters i am married and have 3 children there the dna is halved there. But i have 2 sons so it would be a quarter of my dad's dna but half of mine and half of my hubby's so further down the line it goes it does dilute. But it is never gone.

Answer 2

Nearly but not quite. When an egg is fertilised, both sets of DNA combine to produce a zygote (embryo) that has a full complement of DNA which will allow the development of the organism whether plant, animal or human.
The sex of a child is determined by the combination of two particular chromosomes - cunningly named the sex chromosomes.
Females (eggs) have an "X" chromosomes
, and males (sperm) have one "X" or one "Y" chromosome.
Therefore sex is actually determined by the father - if a sperm with an X fertilizes the egg, then the embryo will have XX and be female; conversely if a sperm with a Y fertilizes the egg, the embryo will be XY and be a male.

A female has half of the father's DNA with the exception only of the male Y chromosome that confers male traits. She will produce XX eggs. One X is donated by the father, who received it from his mother. And so on and so forth. However, the remaining DNA is a combination of the traits of both grandparents.

Mitochondria are small organelles (membrane bound inclusions within each cell of the body) that function as an Energy factory. They contain their own DNA. When cells divide, components are "doubled up" so that each new cell has everything it needs to be viable. The exception is mitochondria - these are not divided up. When the sex cells are produced, these tiny organelles reproduce themselves without any shuffling of the genes - they are clones. These are directly passed into eggs by the mother - the sperm has them, but they are left behind when the head enters the egg. The developing foetus cells contain clone after clone of the female mitochondria. When it produces the sex cells, the mitochondria are the clones of the original maternal mitochondria within the egg that started the person. All mitochondria are female - there are no male mitochondria.

Answer 3

Everyone has Male and Femal DNA inside them, so its not so much DNA thats in issue, its how the DNA is arranged that makes the difference.

Its Chromosomes: There are 2 types of chromosome in relation to Gender, X and Y

Female is a pair of Xs (XX), and a male is XY. A females egg all contain an X sequence of DNA, and they need an X or Y from the Male to complete the egg.

Males Sperms contain different variances of chromosomes, lets say half are 1X and the other half 1Y. If a sperm carrying an X meets with the Egg that already has an X, you will get a Female (XX). If a Y sperm meets the X Egg, you get XY (Male).

What if you get a Sperm containing and XY and an X meeting the X egg, or an egg with XX & an X meeting the normal Y sperm; This is a hermaphrodite.

Typically, you have 96 Chromosomes, of which 48 come from the father, and 48 from the mother. 1 of these 48 of each is the Gender Chromosome.

Answer 4

What do you mean by "the male DNA"?

If you mean the Y chromosome, then yes. The Y chromosome is not passed to the single female child, and thus will be completely lost to the future generations.

If you mean the DNA from the paternal side, then no. The father's X chromosome and 22 other chromosomes from the father are passed to the daughter, just as an X chromosome and 22 other chromosomes are passed from the mother. The father's DNA may continue to pass onto future generations. It is remotely *possible* that none of the father's DNA will get passed on to grandchildren ... just as it is *possible* that that none of the mother's DNA will get passed on ... but it is extremely unlikely. In most cases about 25% of each grandparent's DNA will get passed on to grandchildren.

In future generations, the father's DNA will indeed get diluted by other breedings ... but this is no different from what happens to the mother's DNA.

Summary: It is the Y chromosome, and *only* the Y chromosome (one out of the 23 chromosomes contributed by dad) that does not get transmitted at all from fathers to daughters.

Incidentally, the chromosomes (DNA in the nucleus) are not the only DNA in our cells. There is also DNA in the mitochondria (energy generating organelles) in each of our cells. The mitochondrial DNA is *exclusively* inherited from the mother. So the father's mitochondrial DNA is completely lost in both sons and daughters ... and completely lost to future generations.

Answer 5

The male DNA is not lost, but the chromosome that would have made her a male is. Its really the fathers contribution that determines the sex, because the woman will always donate an x chromosome, and whether the male donates a y or an x determines the sex. There is always a contribution from each parent. The female does not get both x chromosomes from the mother.

Answer 6

TO ANYONE WHO IS IN ANY DOUBT - YOU HAVE 46 CHROMOSOMES in any body cell, not 96!!!!!

23 from father; 23 from mother.

The male DNA ( i.e. the father's DNA ) is not lost; as stated somewhere here, the father contributes 50% of the genetic material of each sibling.

( It would be true to say that if a family only has one child and it is a girl, then the Y chromosome, on which the genes for maleness reside in humans, would be lost. However, the father has still provided 50% of the DNA for the girl. )

Answer 7

The mother and father each contribute 50% of the genetic information to each child. A female child will receive one X chromosome from her mother, and and one X chromosome from her father. Males are XY, and females are XX. The chromosome that determines sex is the smallest human chromosome, which means that very little other information is carried on it. Every normal child receives 22 other chromosomes from each parent (with each gene being selected for randomly, which is why children do not always look like their parents), so the only information that CANNOT be passed on to a female child is the information that programs for the male sex.

Answer 8

To put father's genetic egos at ease: if you have a sister, she can take care of passing your mother's mitochondrial DNA to future generations. It's the same as your own.
Even without a sister, there is hardly any DNA recombination during mitochondrial reproduction and therefore the mitochondrial DNA is pretty much the same across the whole human population.

Answer 9

if the family had one child the father has put in genes into daughter the daughter passes genes on .

if girl had a daughter or son the dna in that child would have similar properties to your dna.

bodies from years ago can be dna tested to see if they are related to a family member alive now.

Answer 10

The male's dna is not lost - there is roughly 49% of it passed on to the daughter.

Female DNA acocunts for 51% on average of your makeup.