Google Answers DNA: Having Children

by Dr. Hsien-Hsien Lei
Posted October 11, 2007 in DNA @ Google Answers

A man on Google Answers wanted to find a woman who’d bear four to 12 children with him. He asks:

How does one find a girl interested in having many children? What’s the best way to go about my search? Should I think about moving to rural
Utah?

In response, one of the comments suggested:

If your main goal is passing along your DNA to the next generation,
you might want to give serious consideration to becoming a sperm
donor.

Well. That just about covers it.

Tags: genetics, genes, dna, paternity, fatherhood, children, kids, babies, google answers

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Google Answers DNA: Mixed-Up Blood

by Dr. Hsien-Hsien Lei
Posted September 20, 2007 in DNA @ Google Answers, DNA and the Law

Google Questioner:

If someone donates blood, and that blood is transfused into someone who later commits a crime that leaves blood evidence at the scene, will the DNA of the donor be at the crime scene or only the DNA of the
person who committed the crime?

My answer:

In 2005, something very similar happened. A man who donated bone marrow to his brother several years earlier was accused of committing a sex attack in Alaska when blood tests matched his DNA profile to the crime. But, it really wasn’t him! It was his brother who committed the crime.

The mix-up resulted because his brother’s blood had some cells that contained the brother’s DNA and other cells that contained his own. Investigators were quick to catch the mistake, however, when they found that the accused was in jail at the time of the attack. Experts emphasized that the chances of this happening to other bone marrow donors were slim to none.

Google Answers found this excellent answer at the Canadian National DNA Databank:

It is possible, but unlikely. It will partly depend on the type of transfusion received. If a person has received only red blood cells (which do not contain DNA), there will be no confusion. If the person has received white blood cells or platelets (both of which contain DNA), there could be a mixture of recipient DNA and donor DNA in the sample. Upon analysis, both DNA profiles would be identified. They will not “mix” to create one, new profile.

Keep in mind that the human body will replace all transfused blood cells within three or four weeks. If the transfusion was minor, the recipient’s original DNA profile would be clearly prominent. If the transfusion was major, the recipient will probably be too ill to commit a serious crime before their body has replaced most of the donor cells.

In those rare cases where two DNA profiles are discovered in a sample, it is always noted and the analysis double checked. Investigators are also notified for further follow up as required.

So if you’re thinking of committing a crime and are prepping by doing the vampire thing beforehand, it won’t work.

Tags: genetics, genes, dna, crime, blood transfusion, blood

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Google Answers DNA – Significance of the Double Helix

by Dr. Hsien-Hsien Lei
Posted August 30, 2007 in DNA @ Google Answers

Google Questioner:

Is there any significance in it [DNA] being a double helix? Wouldn’t a 2 dimensional “ladder” be able to perform the same job of division and replication?

Google Answer:

…I direct your attention to James Watson’s textbook, “Molecular Biology of the Gene, Fifth Edition.” …Watson explains that the double helix structure results from the way that hydrogen bonds connect the base pairs of the each strand and because of how base pairs “stack” on top of each other. Moreover, the twisty double helix shape is essential for the stability of the DNA molecule.

BTW, play the Nobelprize.org Double Helix Game where “you can make copies of DNA molecules and find out which organism the genetic material belongs to!”

Tags: genetics, genes, dna, double helix, google answers

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Google Answers DNA – Chromosomes, Genes, and DNA

by Dr. Hsien-Hsien Lei
Posted August 23, 2007 in DNA @ Google Answers, DNA in General

And so we continue plowing through the wonderful swamp of Google Answers in search of enlightenment.

Google Questioner:

TV programs give the impression that DNA is one long continuous molecule. But I always thought that there was a hierarchy:
(a) Cells contain chromosomes.
(b) Chromosomes contain genes.
(c) Genes contain DNA.

So, I have a couple of questions:
(1) Which is it? Is DNA one long continuous molecule, or is it divided into genes?
(2) Chromosomes are visible under a strong microscope as distinct entities. But how are distinct GENES identified? What marks the beginning and end of a particular gene?
(3) Is there a website that gives a visual representation of the hierarchy
of cells, chromosomes, genes, and DNA?

It’s a good thing our Google Questioner didn’t ask Jason at The Personal Genome because he’d have told him or her that “the gene is dead…oh wait…alive but sloppy.” Thanks for nothing, Jason! The official Google Answer to this question has lots more.

Tags: google answers, genetics, genes, dna, chromosomes

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Google Answers DNA – Who’s yer daddy?

by Dr. Hsien-Hsien Lei
Posted August 16, 2007 in DNA @ Google Answers, DNA Testing

Although Google shut down the Google Answers service at the end of November 2006, it’s still a wealth of information on a variety of topics including genetics and DNA. In this new series at Eye on DNA, I’ll be choosing the most interesting to share with you.

The Question:

Who’s yer daddy?

The Answer:

For many people, this is a simple issue: yer daddy is the person who is married to yer mommy. However, modern society has found many ways of complicating this question. Nevertheless, regardless of the different emotional roles differnet people may play in your life, there is only one male in the world who can be your biological father. For those cases where the answer to your question is not clear, the only resource to turn to is DNA testing.

Continue reading….

Tags: genetics, genes, dna, google answers, paternity testing, paternity test

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