AboutChris Bemes Expertise I will answer questions relating to the identification of bacterial and fungal isolates using phenotypic (macroscopic/microscopic appearance, biochemical bench tests, fatty-acid analysis) as well as genotypic (RiboPrinting) methods. I can also answer questions relating to environmental microbiology, especially those specifically relating to the pharmaceutical industry. I am less familiar with clinical microbiology.
Experience I have worked within the biotech industry for 9 years, most of that time spent in a Quality Control Microbiology laboratory setting.
Within the laboratory, I routinely performed bioburden testing; sterility testing; gel-clot and kinetic LAL testing; biological indicator testing; stability testing; microbial limits testing; media performance/growth promotion testing; microbial identifications testing using API, Vitek, MIDI (GC-MIS) and RiboPrinter identifications systems; total/fecal coliform testing; environmental monitoring; media preparation; stock culture maintenance; qualification of identification test kits and QuantiCult Plus organisms. I executed the QC validation of the DuPont Qualicon RiboPrinter Microbial Characterization System. I also supported sites internationally with the fungal/microbial identification process, the RiboPrinter assay, stock culture maintenance and the microbial identification process flow.
Organizations Nationally Registered Microbiologist, American Society of Microbiology (2005)
Publications Applied and Environmental Microbiology
Education/Credentials B.S. in Microbiology (2000)
Awards and Honors Received my company's 'Best Practice Award' for the Validation of the RiboPrinter Microbial Characterization System, 2004
Question My mother has green eyes, my father has hazel (brown/green) eyes. I have hazel (brown/green) eyes and my husband has brown eyes. His mother has brown and his father has blue. Our son has blue eyes. I have been told that brown dominates so it's confusing to us that our son has blue eyes, when his father & I both have brown eyes. I've read it's nearly impossible for a child of two brown eyed parents to have blue eyes. Do you have an explanation? Any data pertaining to this?
Answer You are correct, the genes for brown eyes are dominant, but quite often two brown eyed parents will have blue eyed children. Here's why:
Everyone carries two copies of the eye color gene - one from their mother, and one from their father. Let's say that a capital "B" represents a gene for Brown eyes (which is dominant), and a lowercase "b" is a gene for Blue eyes (which is recessive). Here are all of the possible combinations of these genes that people could have:
BB (2 copies of the B gene) = Brown Eyes
Bb (1 copy of the B gene, 1 copy of the b gene) = Brown Eyes
bb (2 copies of the b gene) = Blue Eyes
When a gene is called dominant that means that it will always "win" over its partner gene. This is why an individual with the genes "Bb" will always have brown eyes - because the dominant gene "B" is winning over its partner "b".
Now, when people have children, each parent passes ONE copy of their eye color genes (either a single "B" or a single "b") to their offspring. The possibilities for eye color in the offspring (children) can easily be seen by lining up the parents' genes in what is called a Punnet's Square, which is set up like this:
Parent #1
with brown eyes
B | b
|
|
| B Parent #2
___|___ with brown
| eyes
| b
|
|
|
To see what genes the offspring might inherit, you just fill in the four blank areas with the pairs that line up for that box (one from each parent) as follows:
Parent #1
with brown eyes
|
|
|
BB | Bb Parent #2
___|___ with brown
| eyes
Bb | bb
|
|
|
As you can see from the Punnet's Square above, if both parents have brown eyes but also carry the recessive gene for blue eyes, every time they have a child, there is a 1 in 4 chance that their child will have blue eyes (bb).
Also, it should be noted that nearly all babies have dark blue eyes when they are first born. This is because the iris is not yet fully developed in a newborn.
I hope this helps to answer your question. Please let me know if you need any additional help on this matter.
