QUESTIONS :D

[Zebra]

Hi everyone

1.What is a polygene? (Is this a gene that is polygenic? @>@)
2.Difference b/w polygenic and multiple alleles?
3.Difference b/w a chromatid, chromatin and chromosome?
4.What causes variation ? ( I know two. 1 Independent segreation 2 crossing over/recombination)
5.Kinetochore vs centromere (Kinetochore : part of the centromere of a chromosome that is the point of attachment for the spindle fibre) Rather than saying the spindle fibres attach at centromere, it would be more precise to say that the attaching site is the kinetochore?

Thanks ppl

[Zebra]

please... someone help me...

[scar]

Hi everyone

1.What is a polygene? (Is this a gene that is polygenic? @>@)
2.Difference b/w polygenic and multiple alleles?
3.Difference b/w a chromatid, chromatin and chromosome?
4.What causes variation ? ( I know two. 1 Independent segreation 2 crossing over/recombination)
5.Kinetochore vs centromere (Kinetochore : part of the centromere of a chromosome that is the point of attachment for the spindle fibre) Rather than saying the spindle fibres attach at centromere, it would be more precise to say that the attaching site is the kinetochore?

Thanks ppl

1.  Never heard the term polygene.  Sounds like genes that influence a polygenic trait.
2.  Multiple alleles are all at the one gene loci.  eg flowers could be red, pink, yellow or white all based on 1 particular place on the chromosome.  Polygenic traits have 2 or more loci all adding info to the whole.  eg skin colour (polygenic) can be affected by genes on a loci on Chromosome 1  and by other genes sitting on Chromosome 4 etc, etc.  all the info is added up to sayhow dark or light the resulting phenotype is.
4.  Those 2 are really important but the crucial start of the whole thing is still mutation in the germ line genes!