Snowballs Ball Pythons | Often imitated but never duplicated.

Introduction to the Punnett Square

Now that you have the basics in terminology, lets start mixing the genetics. Below you will find the Punnett Square and how it is used to diagram out the passing on of recessive, codominant and dominant genetic traits. It may look intimidating at first glance but once you start to see how the genetics play out it is really quite simple. They start out very basic and get more involved as you scroll down the list of possible combinations. With each passing season and each new designer morph combination that is made, it is becoming more and more important to understand these basic concepts outlined below.

100% Heterozygous (Recessive) to Normal Pairing

100% Heterozygous (Recessive) to Normal Pairing (Aa x aa)	Normal Female (a)	Normal Female (a)
Heterozygous Sire (A)	Heterozygous Aa	Heterozygous Aa
Heterozygous Sire (a)	Normal aa	Normal aa

100% Heterozygous (Recessive) to Normal Pairing
(Aa x aa)
Normal Female (a) Normal Female (a)

Heterozygous Sire (A) Heterozygous Aa Heterozygous Aa
Heterozygous Sire (a) Normal aa Normal aa

All offspring are normal in appearance therefore they are all considered 50% Possible Heterozygous.

100% Heterozygous to 100% Heterozygous Pairing (Recessive)

100% Heterozygous to Heterozygous Pairing (Recessive) (Aa x Aa)	Heterozygous Female (A)	Heterozygous Female (a)
Heterozygous Sire (A)	Homozygous AA	Heterozygous Aa
Heterozygous Sire (a)	Heterozygous Aa	Normal aa

100% Heterozygous to Heterozygous Pairing (Recessive)
(Aa x Aa)
Heterozygous Female (A) Heterozygous Female (a)

Heterozygous Sire (A) Homozygous AA Heterozygous Aa
Heterozygous Sire (a) Heterozygous Aa Normal aa

One in four will be Homozygous in this pairing.

All offspring that are normal in appearance are all considered 66% Possible Heterozygous.

Homozygous to 100% Heterozygous Pairing (Recessive)

Homozygous to 100% Heterozygous Pairing (Recessive) (AA x Aa)	Heterozygous Female (A)	Heterozygous Female (a)
Homozygous Sire (A)	Homozygous AA	Homozygous AA
Homozygous Sire (A)	Heterozygous Aa	Heterozygous Aa

Homozygous to 100% Heterozygous Pairing (Recessive)
(AA x Aa)
Heterozygous Female (A) Heterozygous Female (a)

Homozygous Sire (A) Homozygous AA Homozygous AA
Homozygous Sire (A) Heterozygous Aa Heterozygous Aa

Half of the offspring are Homozygous.

All offspring that are normal in appearance are all considered 100% Heterozygous.

Compatible Homozygous to Homozygous Pairing (Recessive)

Homozygous to Homozygous Pairing (Recessive) (AA x AA)	Homozygous Female (A)	Homozygous Female (A)
Homozygous Sire (A)	Homozygous AA	Homozygous AA
Homozygous Sire (A)	Homozygous AA	Homozygous AA

Homozygous to Homozygous Pairing (Recessive)
(AA x AA)
Homozygous Female (A) Homozygous Female (A)

Homozygous Sire (A) Homozygous AA Homozygous AA
Homozygous Sire (A) Homozygous AA Homozygous AA

The Homozygous forms are compatible or of the same gene and all offspring are Homozygous in appearance.

Different Homozygous to Homozygous Paring (Recessive)

Homozygous to Homozygous Pairing (Recessive) (AA x BB)	Homozygous Female (B)	Homozygous Female (B)
Homozygous Sire (A)	Double Heterozygous AB	Double Heterozygous AB
Homozygous Sire (A)	Double Heterozygous AB	Double Heterozygous AB

Homozygous to Homozygous Pairing (Recessive)
(AA x BB)
Homozygous Female (B) Homozygous Female (B)

Homozygous Sire (A) Double Heterozygous AB Double Heterozygous AB
Homozygous Sire (A) Double Heterozygous AB Double Heterozygous AB

All offspring are normal in appearance and are Double Heterozygous, meaning that they are 100% Heterozygous for each of the two genes involved.

Same Double Heterozygous to Double Heterozygous Pairing (Recessive)

Double Heterozygous to Double Heterozygous Pairing Pairing (Recessive) (AABB x AABB)	Double Heterozygous Female (A)	Double Heterozygous Female (B)	Double Heterozygous Female (AA)	Double Heterozygous Female (AB)
Double Heterozygous Sire (A)	AA (Normal)	AB (Heterozygous B)	AAA (Heterozygous A)	AAB (Heterozygous A, Heterozygous B)
Double Heterozygous Sire (B)	AB (Heterozygous B)	BB (Homozygous B)	AAB (Heterozygous A, Heterozygous B)	ABB (Heterozygous A, Homozygous B)
Double Heterozygous Sire (AA)	AAA (Heterozygous A)	AAB (Heterozygous A, Heterozygous B)	AAAA (Homozygous A)	AAAB (Homozygous A Heterozygous B)
Double Heterozygous Sire (AB)	AAB (Heterozygous A, Heterozygous B)	ABB (Heterozygous A, Homozygous B)	AAAB (Homozygous A Heterozygous B)	AABB (Double Homozygous)*

Double Heterozygous to Double Heterozygous Pairing Pairing (Recessive)
(AABB x AABB)
Double Heterozygous Female (A) Double Heterozygous Female (B) Double Heterozygous Female (AA) Double Heterozygous Female (AB)

Double Heterozygous Sire (A) AA (Normal) AB (Heterozygous B) AAA (Heterozygous A) AAB (Heterozygous A, Heterozygous B)

Double Heterozygous Sire (B) AB (Heterozygous B) BB (Homozygous B) AAB (Heterozygous A, Heterozygous B) ABB (Heterozygous A, Homozygous B)

Double Heterozygous Sire (AA) AAA (Heterozygous A) AAB (Heterozygous A, Heterozygous B) AAAA (Homozygous A) AAAB (Homozygous A Heterozygous B)

Double Heterozygous Sire (AB) AAB (Heterozygous A, Heterozygous B) ABB (Heterozygous A, Homozygous B) AAAB (Homozygous A Heterozygous B) AABB (Double Homozygous)*

In this pairing your offsrping will be as follows: 6.25% Normal, 12.5% Heterozygous B, 6.25% Homozygous B, 12.5% Heterozygous A, 25% Heterozygous A, Heterozygous B, 12.5% Heterozygous A, Homozygous B, 6.25% Homozygous A, 12.5% Homozygous A, Heterozygous B, 6.25% Homozygous A, Homozygous B

Same Double Heterozygous to Double Homozygous Pairing (Recessive)

Double Heterozygous to Double Homozygous Pairing Pairing (Recessive) (AaBb x AABB)	Double Homozygous Female (AB)	Double Homozygous Female (AB)	Double Homozygous Female (AB)	Double Homozygous Female (AB)
Double Heterozygous Sire (AB)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)
Double Heterozygous Sire (aB)	AaBB (Het. a, Homozygous b)	AaBB (Het. a, Homozygous b)	AaBB (Het. a, Homozygous b)	AaBB (Het. a, Homozygous b)
Double Heterozygous Sire (Ab)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)
Double Heterozygous Sire (ab)	AaBb (Het. a, Het. b)	AaBb (Het. a, Het. b)	AaBb (Het. a, Het. b)	AaBb (Het. a, Het. b)*

Double Heterozygous to Double Homozygous Pairing Pairing (Recessive)
(AaBb x AABB)
Double Homozygous Female (AB) Double Homozygous Female (AB) Double Homozygous Female (AB) Double Homozygous Female (AB)

Double Heterozygous Sire (AB) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b)

Double Heterozygous Sire (aB) AaBB (Het. a, Homozygous b) AaBB (Het. a, Homozygous b) AaBB (Het. a, Homozygous b) AaBB (Het. a, Homozygous b)

Double Heterozygous Sire (Ab) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b)

Double Heterozygous Sire (ab) AaBb (Het. a, Het. b) AaBb (Het. a, Het. b) AaBb (Het. a, Het. b) AaBb (Het. a, Het. b)*

In this pairing your offsrping will be as follows: 25% Homozygous a, Homozygous b, 25% Het. a, Homozygous b, 25% Homozygous a, Het. b, 25% Het. a, Het. b.

Homozygous 100% Heterozygous to Double Homozygous Pairing (Recessive)

Double Heterozygous to Double Homozygous Pairing Pairing (Recessive) (AABb x AABB)	Double Homozygous Female (AB)	Double Homozygous Female (AB)	Double Homozygous Female (AB)	Double Homozygous Female (AB)
Double Heterozygous Sire (AB)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)
Double Heterozygous Sire (AB)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)	AABB (Homozygous a, Homozygous b)
Double Heterozygous Sire (Ab)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)
Double Heterozygous Sire (Ab)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)	AABb (Homozygous a, Het. b)

Double Heterozygous to Double Homozygous Pairing Pairing (Recessive)
(AABb x AABB)
Double Homozygous Female (AB) Double Homozygous Female (AB) Double Homozygous Female (AB) Double Homozygous Female (AB)

Double Heterozygous Sire (AB) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b)

Double Heterozygous Sire (AB) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b) AABB (Homozygous a, Homozygous b)

Double Heterozygous Sire (Ab) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b)

Double Heterozygous Sire (Ab) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b) AABb (Homozygous a, Het. b)

In this pairing your offsrping will be as follows: 50% Homozygous a, Homozygous b, 50% Homozygous a, Het. b

Codominant/Dominant to Normal Pairings

Codominant/Dominant to Normal Pairing (Aa x aa)	Normal Female (a)	Normal Female (a)
Codominant/Dominant Sire (A)	Codominant/Dominant Aa	Codominant/Dominant Aa
Codominant/Dominant Sire (a)	Normal aa	Normal aa

Codominant/Dominant to Normal Pairing
(Aa x aa)
Normal Female (a) Normal Female (a)

Codominant/Dominant Sire (A) Codominant/Dominant Aa Codominant/Dominant Aa
Codominant/Dominant Sire (a) Normal aa Normal aa

Half of the offspring are Codominant/Dominant in appearance.

Codominant to Codominant Pairing

Codominant to Codominant Pairing (Aa x Aa)	Codominant Female (A)	Codominant Female (a)
Codominant Sire (A)	Codominant AA Super Form	Codominant Aa
Codominant Sire (a)	Codominant Aa	Normal aa

Codominant to Codominant Pairing
(Aa x Aa)
Codominant Female (A) Codominant Female (a)

Codominant Sire (A) Codominant AA
Super Form
Codominant Aa
Codominant Sire (a) Codominant Aa Normal aa

Three out of four of the offspring are Codominant in appearance with one being the Super Form of the trait.

Super Form (Dominant) to Normal Pairing

Super Form (Dominant) to Normal Pairing (AA x aa)	Normal Female (a)	Normal Female (a)
Super(Dominant) Sire (A)	Codominant Aa	Codominant Aa
Super(Dominant) Sire (A)	Codominant Aa	Codominant Aa

Super Form (Dominant) to Normal Pairing
(AA x aa)
Normal Female (a) Normal Female (a)

Super(Dominant) Sire (A) Codominant Aa Codominant Aa
Super(Dominant) Sire (A) Codominant Aa Codominant Aa

All offspring are the Codominant form of the Super. If the trait is a Dominant trait the results will be the same.

Super to Codominant Pairing

Super to Codominant Pairing (AA x Aa)	Codominant Female (A)	Codominant Female (a)
Super Sire (A)	Super AA	Codominant Aa
Super Sire (A)	Super AA	Codominant Aa

Super to Codominant Pairing
(AA x Aa)
Codominant Female (A) Codominant Female (a)

Super Sire (A) Super AA Codominant Aa
Super Sire (A) Super AA Codominant Aa

Half of the offspring are Supers and half are Codominant in appearance.

Different Double Codominant to Codominant

Different Double Codominant to Codominant Pairing (AaBb x Cc)	Codominant Female (C)	Codominant Female (c)
Double Codominant Sire (AB)	Triple Codominant ABC	Double Codominant ABc
Double Codominant Sire (Ab)	Double Codominant AbC	Codominant Abc
Double Codominant Sire (AB)	Triple Codominant ABC	Double Codominant ABc
Double Codominant Sire (aB)	Double Codominant aBC	Codominant aBc

Different Double Codominant to Codominant Pairing
(AaBb x Cc)
Codominant Female (C) Codominant Female (c)

Double Codominant Sire (AB) Triple Codominant ABC Double Codominant ABc
Double Codominant Sire (Ab) Double Codominant AbC Codominant Abc

Double Codominant Sire (AB) Triple Codominant ABC Double Codominant ABc

Double Codominant Sire (aB) Double Codominant aBC Codominant aBc

One forth of the offspring are Codominant.

One half of the offspring will be Double Codominant.

One forth of the offspring will be Triple Codominant.

Super to Super Pairing

Super to Super Pairing (AA x AA)	Super Female (A)	Super Female (A)
Super Sire (A)	Super AA	Super AA
Super Sire (A)	Super AA	Super AA

Super to Super Pairing
(AA x AA)
Super Female (A) Super Female (A)

Super Sire (A) Super AA Super AA
Super Sire (A) Super AA Super AA

All offspring are Supers.

Codominant to 100% Heterozygous Pairing

Codominant to 100% Heterozygous Pairing (Aa x Bb)	Heterozygous Female (B)	Heterozygous Female (b)
Codominant Sire (A)	Codominant 100% Het AB	Codominant Ab
Codominant Sire (a)	Normal 100% Het aB	Normal ab

Codominant to 100% Heterozygous Pairing
(Aa x Bb)
Heterozygous Female (B) Heterozygous Female (b)

Codominant Sire (A) Codominant 100% Het AB Codominant Ab
Codominant Sire (a) Normal 100% Het aB Normal ab

Half of the offspring are Codominant with one being 100% Heterozygous.

Half of the offspring are Normals with one being 100% Heterozygous.

Codminant to Homozygous Paring

Codominant to Homozygous Pairing (Aa x BB)	Homozygous Female (B)	Homozygous Female (B)
Codominant Sire (A)	Codominant Heterozygous AB	Codominant Heterozygous AB
Codominant Sire (a)	Normal Heterozygous aB	Normal Heterozygous aB*

Codominant to Homozygous Pairing
(Aa x BB)
Homozygous Female (B) Homozygous Female (B)

Codominant Sire (A) Codominant Heterozygous AB Codominant Heterozygous AB
Codominant Sire (a) Normal Heterozygous aB Normal Heterozygous aB*

Half of the offspring are Codominant 100% Heterozygous.

The remaining normal looking offspring are 100% Heterozygous.

Codominant 100% Heterozygous to 100% Heterozygous Pairing

Codominant 100% Heterozygous to Heterozygous Pairing (AaBb x Bb)	Heterozygous Female (B)	Heterozygous Female (b)
Codominant Heterozygous Sire (AB)	Codominant Homozygous ABB	Codominant Heterozygous ABb
Codominant Heterozygous Sire (Ab)	Codominant 100% Heterozygous ABb	Codominant Normal Abb
Codominant Heterozygous Sire (aB)	Homozygous aBB	Normal abb
Codominant Heterozygous Sire (ab)	Normal 100% Heterozygous aBb	Normal abb

Codominant 100% Heterozygous to Heterozygous Pairing
(AaBb x Bb)
Heterozygous Female (B) Heterozygous Female (b)

Codominant Heterozygous Sire (AB) Codominant Homozygous ABB Codominant Heterozygous ABb
Codominant Heterozygous Sire (Ab) Codominant 100% Heterozygous ABb Codominant Normal Abb

Codominant Heterozygous Sire (aB) Homozygous aBB Normal abb

Codominant Heterozygous Sire (ab) Normal 100% Heterozygous aBb Normal abb

Half of the offspring are Codominant.

One forth of the offspring will be Homozygous.

The remaing offsping will be considered 66% Het.

Codominant Homozygous to 100% Heterozygous

Codominant Homozygous to Heterozygous Pairing (AaBB x Bb)	Heterozygous Female (B)	Heterozygous Female (b)
Codominant Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant 100% Heterozygous ABb
Codominant Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant 100% Heterozygous ABb
Codominant Homozygous Sire (aB)	Normal Homozygous aBB	Normal 100% Heterozygous aBb
Codominant Homozygous Sire (aB)	Normal Homozygous aBB	Normal 100% Heterozygous aBb

Codominant Homozygous to Heterozygous Pairing
(AaBB x Bb)
Heterozygous Female (B) Heterozygous Female (b)

Codominant Homozygous Sire (AB) Codominant Homozygous ABB Codominant 100% Heterozygous ABb
Codominant Homozygous Sire (AB) Codominant Homozygous ABB Codominant 100% Heterozygous ABb

Codominant Homozygous Sire (aB) Normal Homozygous aBB Normal 100% Heterozygous aBb

Codominant Homozygous Sire (aB) Normal Homozygous aBB Normal 100% Heterozygous aBb

Half of the offspring will be Codominant.

Half of the offsrping will be Homozygous with a chance at a Codominant Homozygous.

The remainig offsrping are 100% Heterozygous.

Codominant Homozygous to Compatable Homozygous Pairing

Codominant Homozygous to Compatable Homozygous Pairing (AaBB x BB)	Homozygous Female (B)	Homozygous Female (B)
Codominant Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant Homozygous ABB
Codominant Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant Homozygous ABB
Codominant Homozygous Sire (aB)	Normal Homozygous aBB	Normal Homozygous aBB
Codominant Homozygous Sire (aB)	Normal Homozygous aBB	Normal Homozygous aBB

Codominant Homozygous to Compatable Homozygous Pairing
(AaBB x BB)
Homozygous Female (B) Homozygous Female (B)

Codominant Homozygous Sire (AB) Codominant Homozygous ABB Codominant Homozygous ABB
Codominant Homozygous Sire (AB) Codominant Homozygous ABB Codominant Homozygous ABB

Codominant Homozygous Sire (aB) Normal Homozygous aBB Normal Homozygous aBB

Codominant Homozygous Sire (aB) Normal Homozygous aBB Normal Homozygous aBB

All offspring will be Homozygous with half being Codominant.

Codominant Homozygous to Different Homozygous Pairing

Codominant Homozygous to Different Homozygous Pairing (AaBB x CC)	Homozygous Female (C)	Homozygous Female (C)
Codominant Homozygous Sire (AB)	Codominant 100% Double Heterozygous ABC	Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (AB)	Codominant 100% Double Heterozygous ABC	Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (aB)	Normal 100% Double Heterozygous aBC	Normal 100% Double Heterozygous aBC
Codominant Homozygous Sire (aB)	Normal 100% Double Heterozygous aBC	Normal 100% Double Heterozygous aBC

Codominant Homozygous to Different Homozygous Pairing
(AaBB x CC)
Homozygous Female (C) Homozygous Female (C)

Codominant Homozygous Sire (AB) Codominant 100% Double Heterozygous ABC Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (AB) Codominant 100% Double Heterozygous ABC Codominant 100% Double Heterozygous ABC

Codominant Homozygous Sire (aB) Normal 100% Double Heterozygous aBC Normal 100% Double Heterozygous aBC

Codominant Homozygous Sire (aB) Normal 100% Double Heterozygous aBC Normal 100% Double Heterozygous aBC

All offspring will be 100% Double Heterozygous with half being Codominant.

Super Homozygous to Homozygous Pairing

Super Homozygous to Homozygous Pairing (AABB x BB)	Homozygous Female (B)	Homozygous Female (B)
Super Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant Homozygous ABB
Super Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant Homozygous ABB
Super Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant Homozygous ABB
Super Homozygous Sire (AB)	Codominant Homozygous ABB	Codominant Homozygous ABB

Super Homozygous to Homozygous Pairing
(AABB x BB)
Homozygous Female (B) Homozygous Female (B)

Super Homozygous Sire (AB) Codominant Homozygous ABB Codominant Homozygous ABB
Super Homozygous Sire (AB) Codominant Homozygous ABB Codominant Homozygous ABB
Super Homozygous Sire (AB) Codominant Homozygous ABB Codominant Homozygous ABB
Super Homozygous Sire (AB) Codominant Homozygous ABB Codominant Homozygous ABB

All of the offspring will be Codominant Homozygous.

Super Homozygous to Different Homozygous

Super Homozygous to Different Homozygous Pairing (AABB x CC)	Homozygous Female (C)	Homozygous Female (C)
Codominant Homozygous Sire (AB)	Codominant 100% Double Heterozygous ABC	Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (AB)	Codominant 100% Double Heterozygous ABC	Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (AB)	Codominant 100% Double Heterozygous ABC	Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (AB)	Codominant 100% Double Heterozygous ABC	Codominant 100% Double Heterozygous ABC

Super Homozygous to Different Homozygous Pairing
(AABB x CC)
Homozygous Female (C) Homozygous Female (C)

Codominant Homozygous Sire (AB) Codominant 100% Double Heterozygous ABC Codominant 100% Double Heterozygous ABC
Codominant Homozygous Sire (AB) Codominant 100% Double Heterozygous ABC Codominant 100% Double Heterozygous ABC

Codominant Homozygous Sire (AB) Codominant 100% Double Heterozygous ABC Codominant 100% Double Heterozygous ABC

Codominant Homozygous Sire (AB) Codominant 100% Double Heterozygous ABC Codominant 100% Double Heterozygous ABC

All offspring will be Codominant 100% Double Heterozygous.