Both sex chromosomes are acrocentric, and X is larger than Y.
They may be caused by genes on either autosomal or sex chromosomes.
They have no sex chromosomes.
Most multicellular organisms have two sets of chromosomes; that is, they are diploid.
the genome of a single individual (J. Craig Venter) in which both sets of chromosomes were sequenced.
Fertilized eggs get two sets of chromosomes, one from each parent, and so larva develop into diploid females, while unfertilized eggs only contain one set from the mother, so develop into haploid males or drones.