1. how does the principle of independent assortment apply to chromosomes?

2. if two genes on the same chromosome but usually assort independently, what does that tell you about how close together they are?

3.in asexual reproduction, mitosis occurs but meiosis does not occur. which type of reproduction-sexual or asexual- results in off-spring with greater genetic variation?

1) It is the chromosomes, however, that assort independently, not individual genes.

2)  It tells you they're really far apart.
You see, there's this phenomenon called crossing over. Chunks of DNA get randomly swapped between homologous chromosomes. If two genes are close together they're usually swapped together and if they're far apart (say, on opposite ends) they're probably never going to be swapped together because half a chromosome doesn't normally cross over at once.

3)  Sexual reproduction, because it results in offspring that combine alleles from two different individuals. 

(Crossover is fine and dandy and you should mention it, but you'd get a C if you didn't mention that two different individuals are contributing genetic material to the offspring)