How similar are we?
The results of the traits analysis of the entire sec2 cohort is in moodle:
http://moodle.rgs.edu.sg/moodle/mod/questionnaire/report.php?instance=77&sid=97&qact=vresp
In the entire secondary two cohort, Only Lai Yan and Crisann are twins in 210, based on only 6 traits. Ms Tan said that curly hair is actually a dominant gene in almost everyone! That's why our hairs curl up, even slightly, when we tie up our hair and have flyaways.
Dominant and Recessive Genes
We learnt the basics of this in Primary school, but we touched on some more advanced stuff today.
Prior knowledge:
This refers to the relationship between two variant forms of the same alleles of a single gene.
Punnet squares - Used to predict the outcome of a particular breeding, e.g. the traits of an offspring based on the parents' genes.
Today, Ms Tan talked about how meiosis occurs:) Females will always pass on 23 chromosomes with an X chromosome, while a Male may pass on X or Y chromosomes.
We did an activity of cutting and pasting two sets of chromosomes based on banding and length.
Set A: Male down syndrome. 45 + XY
Set B: 44 + XXY. Klinefelter's syndrome. The male will have both male and female characteristics as he has an extra X chromosome
YO - Y determines the gender of the person. This baby will have a spontaneous miscarriage as no human can survive without an X chromosome:) The body will recognise the baby and immediately "reject" it.
XO - Unlike YO, this person can survive. Turner's syndrome. 1 in 2500 female births.
XXX - Super female. Quite sad actually, as these people will suffer from mental retardation, infertility and other not very nice symptoms:(
http://en.wikipedia.org/wiki/Triple_X_syndrome
YYY - Super male
Hence, to sum up, there are monosomy and trisomy chromosome conditions!
In blood, people with a negative behind their letter cannot conceive children naturally as their bodies will naturally produce antibodies against their babies:(
We did an activity of cutting and pasting two sets of chromosomes based on banding and length.
Set A: Male down syndrome. 45 + XY
Set B: 44 + XXY. Klinefelter's syndrome. The male will have both male and female characteristics as he has an extra X chromosome
YO - Y determines the gender of the person. This baby will have a spontaneous miscarriage as no human can survive without an X chromosome:) The body will recognise the baby and immediately "reject" it.
XO - Unlike YO, this person can survive. Turner's syndrome. 1 in 2500 female births.
XXX - Super female. Quite sad actually, as these people will suffer from mental retardation, infertility and other not very nice symptoms:(
http://en.wikipedia.org/wiki/Triple_X_syndrome
YYY - Super male
Hence, to sum up, there are monosomy and trisomy chromosome conditions!
In blood, people with a negative behind their letter cannot conceive children naturally as their bodies will naturally produce antibodies against their babies:(
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