mosaicism cat aka calico aka tortoiseshell cat

The text doesn't explicitly mention the key 'mosaicism' but based on its context within a broader discussion about genetics and inheritance, it is reasonable to infer that the concept of mosaicism might be related to genetic variation or mixed cell populations.

In biology, mosaicism refers to a condition where an individual's cells are genetically different from one another. This can occur due to various reasons such as errors during cell division (mitotic recombination), exposure to mutagenic agents that cause mutations in some but not all dividing cells (somatic mutation), or even through the presence of two fertilizing spermatozoa or oocytes each carrying a distinct set of chromosomes and thus resulting in an individual with mosaic chromosomal constitution, known as triploidy.

In cats specifically, mosaicism is more commonly associated with coat color inheritance. Female tortoiseshorfs are typically carriers for X-linked dilute (d) alleles on one copy of their two copies of the gene encoding tyrosinase-related protein 1(Tyrp1), while males carry only Y-bearing spermatozoa that do not inherit this allele from their mother and therefore cannot pass it onto offspring. When these females mate with male carriers, there is a chance (25%) for each kitten to inherit both copies of the recessive dilute allele through either autosomal or X-linked inheritance patterns depending upon whether they inherit two copies via spermatozoon fertilization or egg cell cytoplasmic factors respectively giving rise to tortoiseshell pattern due to dosage effect resulting from unequal expression levels between different tissues such as skin vs fur follicles leading sometimes even within same litter varying degrees of mosaicism ranging anywhere from completely solid black tabby patches over predominantly brown coats down towards almost all white cats depending on exact combination inherited post fertilization.

Mosaicism cat aka calico aka tortoiseshell cat