Here's why this makes a mule unique:
* Different Chromosome Counts: Horses have 64 chromosomes, while donkeys have 62.
* Sterility: This difference in chromosomes makes mules sterile – they cannot reproduce. This is because the chromosomes cannot pair up properly during meiosis, the process that creates sex cells (sperm and eggs).
Why were mules created?
* Strength and Hardiness: Mules inherit the donkey's strength, endurance, and sure-footedness, and the horse's size and speed.
* Disease Resistance: They are less susceptible to some diseases than horses.
* Longer Lifespan: Mules tend to live longer than horses.
So, a mule is a fascinating example of how different species can combine their traits, even if the result is a sterile offspring.