T of F? A person's DNA is derived equally from both the mother and father?

[BlondeCookie]

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Just a quick question. I got into a friendly spat with a know-it-all friend today concerning DNA. Does an equal amount one's DNA come from both the father and mother? Does the mother contribute exactly 1/2 of a person's genetic material and the father contribute exactly 1/2 of that person's genetic material?

 

[Valency]

I should think not since mitochondrial DNA is inherited only from the mother.

 

[DrChandy]

Just a quick question. I got into a friendly spat with a know-it-all friend today concerning DNA. Does an equal amount one's DNA come from both the father and mother? Does the mother contribute exactly 1/2 of a person's genetic material and the father contribute exactly 1/2 of that person's genetic material?

The answer is both yes, and no.

In terms of the number of chromosomes, both mother and father each contribute exactly 23 to the child.

In terms of the overall bulk (overall nucleotide count) of genetic material, males contribute less than females (in the case of a male offspring), as the Y chromosome is significantly shorter than its X chromosome counterpart. Concurrently, the above post applies to offspring characterized by both sexes.

 

[Noeljan]

each contributes their n gamete which then restore 2n by fertilization, but mitochondria (which contain its own DNA) are only passed by the mother.

 

[el.harpo]

The answer is both yes, and no.

In terms of the number of chromosomes, both mother and father each contribute exactly 23 to the child.

In terms of the overall bulk (overall nucleotide count) of genetic material, males contribute less than females (in the case of a male offspring), as the Y chromosome is significantly shorter than its X chromosome counterpart. Concurrently, the above post applies to offspring characterized by both sexes.

Yep. In the case of male offspring, in terms of the number of coding genes, the mother contributes more. In terms of chromosomes, they both contribute an equal number. In the case of women, you could make your arguement that mothers contribute mitochondrial genetic material.

 

[RobbingReality]

Don't forget about trisomy 21 and other polysomal disorders.

 

[el.harpo]

Don't forget about trisomy 21 and other polysomal disorders.

Can't you get Trisomy 21 from either side (maternal or paternal) due to 14.21 translocation or non-disjunction? I don't believe counting that would make any difference.

 

[bioteacher]

All the above is correct.

Now if you want to sound smart, ask your friend if they will pass half of each of their parents' DNA to their offspring.

The answer is no. They may pass significantly more of their mother's or father's DNA through the process of independent assortment and crossing over of homologous chromosomes.

This really isn't your question but it fits in somewhere. Besides I think it's cool.

 

[BlondeCookie]

All good answers!
So to recap...

Q: Is DNA passed down in equal amounts from the mother / father?
A: No - because mitochondrial DNA comes solely from the mother. Mom contributes more.
A: No - because, in the case of males, the X chromosome (from mom) is longer than the Y chromosome (from dad). Mom contributes more again.
A: Yes - if you are solely looking at genes... 23 from Dad and 23 from Mom!

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So, on a test if the question is rephrased like below, would it make any difference in the answer???

Q: Is genetic material (not sole DNA) passed down in equal amounts from the mother / father?
A: Yes or no?

 

[hnbui]

Just a quick question. I got into a friendly spat with a know-it-all friend today concerning DNA. Does an equal amount one's DNA come from both the father and mother? Does the mother contribute exactly 1/2 of a person's genetic material and the father contribute exactly 1/2 of that person's genetic material?

false

 

[Nutmeg]

First Blonde Girl, then BlondeChick, now BlondeCookie... no overlap between posting times, all posting in the MCAT forum, and none more than about three months old... and the only two other usernames ever registered beginning with "blonde" each have only one post total... waht're the odds? 🙄

How many usernames are you going to register?

 

[BlondeCookie]

First Blonde Girl, then BlondeChick, now BlondeCookie... no overlap between posting times, all posting in the MCAT forum, and none more than about three months old... and the only two other usernames ever registered beginning with "blonde" each have only one post total... waht're the odds? 🙄

How many usernames are you going to register?

That reply was quite rude and obnoxious. FYI, I have no idea what you are talking about. I am new to this forum and I really had no idea that there were others with similar usernames. A coincidence, yes. But, how about checking the attitude at the door?

 

[Nekbat]

hahahahaha, you people crack me up