I'm Stephanie (13)
I am trying to plan, over my Easter holidays, a system for introducing
diploid cell (Is that the right term? I mean the possibility of
recessive genes, so double the DNA.) into an artificial life game I
play. I keep coming up against a major stumbling block: chromosomes.
I especially want to clear up these points (I will try to get all the
Do chromosomes carry dominant/recessive forms of the same gene (alleles)
together on one chromosome, or are they carried on different chromosomes
and the chromosomes 'pair up'?
If they don't pair up, why does colour blindness affect males
What exactly are chromatids, and why do we need them?
What are double-stranded chromosomes, and why do we need them?
Why, before a cell is about to undergo meiosis, does it have twice the
genetic information in a normal cell, when, if it had half, it could
just divide straight away?
What is the point of crossover? Does it give an evolutionary advantage,
or is it just a side effect?
I would be very grateful if anyone could give up a few minutes of their
time to answer some of these questions for me.