This morning I failed my driving test.
Thursday, 3 May 2007
Wednesday, 2 May 2007
[[Genetic]] Crossing
Genetics. So much fun to find out where you came from and who you will be producing. Luckily, its part of the A level course, so typing this can be classed as Biology revision. Or I can just tell myself that to make myself feel better. Ah, procrastination! It lurks in so many forms.
Sitting in Chemistry today, I was hugging the radiator (is it my fault that I sit right next to it?) listening to Dr Goode go through the test scores and I suddenly thought that I could work out the percentage chance that I would have a colourblind child. Thoughts like that constantly run through my mind in chemistry...occupational hazard of being a student.
My cricket-and-football-playing Dad is colourblind, so much so it ruined his dream of being a pilot. I decided that I wanted to know whether I would have to dash the dreams of my child should he or she take a mind to pilot an aeroplane, or perhaps a shuttle craft. Or a hot air balloon.
So I decided, sat in Chemistry being told that my for answer to question 3b) iii) I had used the wrong mole ratio and therefore would loose a mark, that when I got home I would draw out some genetic crosses and find out, thus satisfying my urge and revising at the same time. Half a day later, I am now sat infront of the computer (but only because my TV refuses to work so I cant watch the Apprentice) ready to work it out.
The colourblindness disease is sez-linked, so the alleles that I am using for this cross are:
XN = normal
Xn = colourblind
Y = normal (male)
First, I must work out my genotype.
My dad is colourblind, therefore he carries the gene for it, so his genotype is XnY and my mum knows that she is not a carrier, therefore her genotype is XNXN.
The genetic cross for my genotype (f1) is:
........Xn...... Y
XN XNXn XNY
XN XNXn XNY
As shown in red, my genotype is XNXn, which means that I am a carrier of colourblindness. Note that my brother does not carry the disease, as my dad must pass on the Y chromosome to him, which does not contain the allele for colourblindness, and the X chromosome he recives from my mother contains the normal allele, as she does not carry a copy of the colourblind allele.
If I was to marry and start a family with a man who was not colourblind, then the genetic cross would look like this. Note that men cannot carry the disease as it is only on the X chromosome, which they only have one copy of.
.........XN......Y
XN XNXN XNY
Xn XNXn XnY
There is a 25% chance that I would have a normal, non-carrying female and a 25% chance that I would have a normal male, while there is a 25% chance that I would have a carrying female and 25% chance that I would have a suffering male. Note that it is impossible for any female offspring to suffer from colourblindness.
If I married and started a family with a man who suffered from colourblindness, then the genetic cross would look like this:
........Xn.......Y ........
XN XNXn XNY
Xn XnXn XnY
There is a 25% chance that I would have a normal, carrying female and a 25% chance that I would have a normal male, while there is a 25% chance that I would have a female who suffered from colourblindness, and a 25% chance that I would have a male who suffered from colourblindness. Note that I would not have a female who did not carry the diesease.
This practise has told me that I would have to crush the flying dreams of 3/8 of my kids. I got depressed, I mean what Mother would want to do that to her own Children? And then I remembered that I am only 17, and by the time that I am ready to have children, scientists will have probably developed 'designer' children, so that you can pick the traits that your children have.
See. I told you genetics was intersting.
Sitting in Chemistry today, I was hugging the radiator (is it my fault that I sit right next to it?) listening to Dr Goode go through the test scores and I suddenly thought that I could work out the percentage chance that I would have a colourblind child. Thoughts like that constantly run through my mind in chemistry...occupational hazard of being a student.
My cricket-and-football-playing Dad is colourblind, so much so it ruined his dream of being a pilot. I decided that I wanted to know whether I would have to dash the dreams of my child should he or she take a mind to pilot an aeroplane, or perhaps a shuttle craft. Or a hot air balloon.
So I decided, sat in Chemistry being told that my for answer to question 3b) iii) I had used the wrong mole ratio and therefore would loose a mark, that when I got home I would draw out some genetic crosses and find out, thus satisfying my urge and revising at the same time. Half a day later, I am now sat infront of the computer (but only because my TV refuses to work so I cant watch the Apprentice) ready to work it out.
The colourblindness disease is sez-linked, so the alleles that I am using for this cross are:
XN = normal
Xn = colourblind
Y = normal (male)
First, I must work out my genotype.
My dad is colourblind, therefore he carries the gene for it, so his genotype is XnY and my mum knows that she is not a carrier, therefore her genotype is XNXN.
The genetic cross for my genotype (f1) is:
........Xn...... Y
XN XNXn XNY
XN XNXn XNY
As shown in red, my genotype is XNXn, which means that I am a carrier of colourblindness. Note that my brother does not carry the disease, as my dad must pass on the Y chromosome to him, which does not contain the allele for colourblindness, and the X chromosome he recives from my mother contains the normal allele, as she does not carry a copy of the colourblind allele.
If I was to marry and start a family with a man who was not colourblind, then the genetic cross would look like this. Note that men cannot carry the disease as it is only on the X chromosome, which they only have one copy of.
.........XN......Y
XN XNXN XNY
Xn XNXn XnY
There is a 25% chance that I would have a normal, non-carrying female and a 25% chance that I would have a normal male, while there is a 25% chance that I would have a carrying female and 25% chance that I would have a suffering male. Note that it is impossible for any female offspring to suffer from colourblindness.
If I married and started a family with a man who suffered from colourblindness, then the genetic cross would look like this:
........Xn.......Y ........
XN XNXn XNY
Xn XnXn XnY
There is a 25% chance that I would have a normal, carrying female and a 25% chance that I would have a normal male, while there is a 25% chance that I would have a female who suffered from colourblindness, and a 25% chance that I would have a male who suffered from colourblindness. Note that I would not have a female who did not carry the diesease.
This practise has told me that I would have to crush the flying dreams of 3/8 of my kids. I got depressed, I mean what Mother would want to do that to her own Children? And then I remembered that I am only 17, and by the time that I am ready to have children, scientists will have probably developed 'designer' children, so that you can pick the traits that your children have.
See. I told you genetics was intersting.
Tuesday, 1 May 2007
Many Centuries [[Ago]]
There are cookies in the oven and the house smells like warm banana's, chocolate and just baked cookies. And my mouth tastes like cookie dough. I really should stop doing that - eating the dough while I cook. Revision for the day is done and I am waiting for my mum to get
home from work so that I can go and practise driving. But now I'm looking back at my last blog...where was I?
A con-artist with too much time on my hands. Well, I can assure you that I am not. Though perhaps I do have too much time on my hands if I can sit here and write this. But when I have finished everything...why not?
My family and friends are perhaps the most important people in my life. My Mother is the most inspirational person I know...not only is she a mother, but she is a teacher as well, not only my guiding light, but the guiding light to many other children. My Dad, 42 years old and still playing sunday league football and cricket. Thats amazing. If I'm still doing all my sports when Im 40, then I'll count myself as incredably lucky.
My brother...what can I say? He is 16 in ten days, where has the time gone? He's done as many sports as me in as much time (I guess that makes him a sports orientated con artist with too much time as well).
home from work so that I can go and practise driving. But now I'm looking back at my last blog...where was I?
A con-artist with too much time on my hands. Well, I can assure you that I am not. Though perhaps I do have too much time on my hands if I can sit here and write this. But when I have finished everything...why not?
My family and friends are perhaps the most important people in my life. My Mother is the most inspirational person I know...not only is she a mother, but she is a teacher as well, not only my guiding light, but the guiding light to many other children. My Dad, 42 years old and still playing sunday league football and cricket. Thats amazing. If I'm still doing all my sports when Im 40, then I'll count myself as incredably lucky.
My brother...what can I say? He is 16 in ten days, where has the time gone? He's done as many sports as me in as much time (I guess that makes him a sports orientated con artist with too much time as well).
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