Can a chocolate lab female and male produce all black puppies?

Yes, it is possible for a chocolate Lab female and male to produce all black puppies. To understand how this is possible, it is important to know the genetics behind coat colour in Labradors.

Labradors can have three different coat colours: black, chocolate, and yellow. The coat colour of a Labrador is determined by two genes, known as the B and E genes. The B gene controls the amount of black pigment in the coat, while the E gene controls the distribution of black pigment.

The B gene has two alleles, B and b. The B allele produces black pigment, while the b allele produces brown pigment. The E gene also has two alleles, E and e. The E allele allows black pigment to be distributed evenly throughout the coat, while the e allele restricts black pigment to certain areas of the coat.

In order for a Labrador to have a black coat, it must have at least one B allele and at least one E allele. A chocolate Labrador will have two b alleles and at least one E allele. A yellow Labrador will have two b alleles and two e alleles.

If a chocolate Lab female and male mate, they can produce puppies that are black, chocolate, or yellow. The probability of each coat colour depends on the genotype of the parents.

If the chocolate Lab female has the genotype bbEe and the chocolate Lab male has the genotype bbEe, all of their puppies will be black. This is because both parents will contribute a b allele and an E allele to each puppy, resulting in a genotype of bbEe for all puppies.

If the chocolate Lab female has the genotype bbEE and the chocolate Lab male has the genotype bbEe, half of their puppies will be black and half will be chocolate. This is because the chocolate Lab female will contribute an E allele to each puppy, while the chocolate Lab male will contribute either an E allele or an e allele. Puppies that receive an E allele from both parents will be black, while puppies that receive an e allele from one parent will be chocolate.

If the chocolate Lab female has the genotype bbEe and the chocolate Lab male has the genotype bbee, all of their puppies will be chocolate. This is because the chocolate Lab female will contribute an E allele to each puppy, while the chocolate Lab male will only contribute an e allele. Puppies that receive an E allele from the chocolate Lab female and an e allele from the chocolate Lab male will be chocolate.