alleles

Certain types of rabbits…

…can either be brown, white, have a chinchilla pattern, or have a himalayan pattern

C causes fully brown coatcc causes albino (white)cch causes a chinchilla patternch causes a Himalayan patternThe alleles are arranged in the following

pattern C > cch > ch > c

Full color rabbit – alleles are dominant to all others; CC, Ccch, Cch, or Cc

Chinchilla rabbit – partial defect in pigmentation

cch allele dominant to all other alleles except C; cchch, cchcch, or cchc

• Himalayan rabbit – color in certain parts of the body; dominant only to c; chc or chch

• Albino rabbit – no color – allele is recessive to all other alleles; cc

C > cch > ch > cPredict the outcome of the following cross:

A full brown rabbit (Cch) and chinchilla (cchc) patterned rabbit mate…what phenotypes would you predict in the offspring? (…and in what percentages?)

• How does this type of inheritance differ from what we’ve done in the past?

Answer There are more than two alleles for hair color in rabbits. 1 trait = more than 2 alleles… This type of inheritance is called…

…Multiple Allele Inheritance (when 3 or more alleles exist for a given trait)

A rabbit’s coat color is determined by a single gene that has at least 4 different alleles.

What other traits are controlled by multiple alleles?

4 possible phenotypes: A, B, AB or O

6 possible genotypes: A – type A (IAIA)

type A (IAi)

B – type B (IBIB)

type B (IBi)

AB – type AB (IAIB)

O – type O (ii)

Every person carries two alleles for blood type (out of a total of three allele options – (IA), (IB), (i)

Practice Problems

IAi x IAi (A x A)IBi x ii (B x O)IAIA x IBi (A x B)A couple, both of whom have type

AB blood, can have children with how many different blood types? What are they?