Small questions

[n.f]

In a karyotype the number of each autosomal gene is 4? One for each chromatid?

What exactly needs to be known on linked genes for the exam?

Thanks in advance

[qshyrn]

In a karyotype the number of each autosomal gene is 4? One for each chromatid?

What exactly needs to be known on linked genes for the exam?

Thanks in advance

no, there is usually only one of the gene on each homologous chromosome, meaning usually 2 of the autosomal genes present.
However, i read that there can be cases where there multiples of genes in the genome.

i think you need to know that linked genes belong on the same chromosome/linkage group. you have to know how to spot linked genes when they give you a dihybrid cross (its when the percentage of offspring phenotype is not 25:25:25:25 , but  (high number):(high number): (low number): (low number) )

i dont think i explained things well but anyway..

[n.f]

A few more areas from questions that I'm struggling with:
'The non-coding regions of the Y chromosome are called heterochromatin. This accumulates mutations much more rapidly compared with the DNA contained within the gene loci. The VNTRs in the heterochromatin on the Y chromosome provide genetic markers for biologists to track the descent of individuals over large periods of time.
a) Why does the Y chromosomal heterochromatin accumulate mutations more rapidly compared with the DNA of the gene loci?

b) Why would the VNTRs in the heterochromatin of the Y chromosome be useful in studies of human descent?
Only passed on the paternal line?

Is it scientifically reasonable to reconstruct a whole skeleton based on small bone fragments? Explain why

How after plasmids with desired genes are isolated are they inserted into organisms? Are they inserted into germ line cells to make a line of transgenic organisms?

Thanks to anyone who can assist me.