Chromosomes

[mekamitchell]

Will inheriting extra or insufficient copies of each chromosome be beneficial, detrimenta, or have no effect on offspring? Why?

[JackBean]

Insufficient copies will be probably always detrimenta, if that means bad
Extra copies could be beneficial, if there where some good genes*), but usually that leads to various genetic disorders, like the Down syndrome. Look at these links
http://en.wikipedia.org/wiki/Genetic_disorder
http://en.wikipedia.org/wiki/List_of_genetic_disorders


EDIT
*) and vice versa, deletion could be beneficial, if bad genes were deleted

[kolean]

It would all be detrimental, since you stated whole chromosomes. It all has to do with dosage compensation of gene products. This is why even the double X chromosomes in females has to have one of the chromosomes be inactivated, so as not to cause detrimental effects to the organism. While the only X in the male (along with the Y chromosome) is fully activated.
Balance is the key. You can not have too little of one gene product and too much of a gene product.

[MrMistery]

@kolean
not necessarily. Yes in humans that is the case. But for example in plants poliploidy is often seemed and it has been a beneficial thing for plants in cold climates. And if you have an organism like an ophioglossum fern which has its genome divided between around n=600 chromosomes, an extra chromosome has so few genes that it may just be beneficial in some environments.

[kolean]

True, I do seem to assume animal as the organism in question.

[JackBean]

Yeah, people usually assume animals as all organisms...
But in this case, as is it in Human Biology, you were probably right:)