In another lesson, we learned about Earth's four spheres. These are the geosphere, hydrosphere, biosphere and atmosphere. Together, they make up all of the components of our planet, both living and non-living.
All kittens should be born with two anatomical openings just below the tail. One is the anus and the other one is the genital area. The primary way to tell a female kitten from a male kitten is by comparing the distance between the anal opening and the genital opening. Rarely, a kitten may be born without an anus. This is a birth defect and is considered very serious and life threatening.
Calico cats are almost always female because the locus of the gene for the orange/non-orange coloring is on the X chromosome. In the absence of other influences, such as color inhibition that causes white fur, the alleles present in those orange loci determine whether the fur is orange or not.