Human and other primate karyotypes
Human diploid 46 all other great apes 48.
The most significant chromosomal difference between humans and chimpanzees is a reduction by one of the haploid chromosome number.

What appears to have happened is that at some time since the Pan/Homo split, two chromosomes of a primate ancestor fused into one. Resulting in the human haploid number to be one less. 24 to 23. It is reasonable to assume that this happened after the split with the apes because Gorilla and Pongo (chimps) have the same, ancestral chromosomal structure.

The fusion of what might be termed ancestral chromosome 2 & 3, appears to have occurred on both p arms, close to the telomere, losing one of the centromeres and some genetic material, from the two p arm tips, in the process.

According to the visible evidence of banding patterns, the modern human chromosome is fused at the point 2q13.


Whiptail lizard

The virgin whiptail lizard ( Cnemidophorus neomexicanus ) of the western United States has only females in its population. One female mounts and clasps another female, presumably to induce ovulation. Assuming that the lizards are diploid and their unfertilized eggs develop by mitotic oögenesis (without the reduction division of normal meiosis), then their offspring would be clones of each other.

Honeybees

Drones (males) result from unfertilized eggs (parthenogenesis).They have no father.

All eggs and sperm carry 16 chromosomes each. Each egg contains a unique combination of 50% of the queens genes.

All 10 million sperm produced by a drone/male are identical clones. Haploid drone bees produce haploid sperm in their testes through a mitotic spermatogenesis without a meiotic reduction division.
Since each queen mates with 10-20 drones, colonies are comprised of subfamilies of workers/daughters, each having the same mother (the Queen) but different fathers (whichever drones mated with the Queen).

In honeybees, the sex of each individual is NOT determined by the presence of sex chromosomes. Instead, the sex of a honeybee is determined by the number of chromosomes it has. Male honeybees develop from unfertilized eggs also laid by the Queen. PARTHENOGENESIS. So, she has the ability to lay eggs that were either fertilized (worker) or not fertilized (drone).

Workers/females of the same subfamily are related by 75% of their genes. This "extra" close relatedness may explain the cooperative, and altruistic (to benefit others over yourself) behaviors found in colonies.

It also explains why workers forego their own reproduction in favor of helping their queen mother raise more sisters.Their sisters are more closely related to them than their own offspring would be. (75% vs 50%).

Female honeybees develop from fertilized eggs and thus have double the number of chromosomes in males. Thus honeybee males have 16 chromosomes while females have 32 chromosomes.

Although the haploid drone comes from an unfertilized egg with only one set of maternal chromosomes, they are certainly not all genetically identical. The diploid queen bee undergoes normal meiosis (oögenesis) producing haploid eggs. During this meiotic process her 16 pairs of homologous chromosomes become altered by crossing over and reshuffled through random assortment, resulting in haploid eggs that are not chromosomally identical. In fact, with 16 pairs of homologous chromosomes, there are 2 ¹⁶ or 65,536 different chromosomal combinations possible.