If the resulting F1 rabbits are crossed, what proportion of the F2 offspring will have the Himalayan phenotype and what causes the hypomorphic ch allele to be unstable and result in the distinctive fur pattern

3/4; temperature

Explanation:

When animal are crossed to produce a different hybrid having the features or characteristics of both the two crossed animal, a hybrid offspring is produced. The hybrid offspring have all the qualities and characteristics of the parents.

When a parental cross is done between rabbit with albino rabbit, having genotype cc and with Himalayan phenotype that have a genotype of chch, it results in the production of F1 rabbits having all the Himalayan phenotype.

And if the F1 rabbits are now crossed, three-fourth of the F2 offspring have the Himalayan phenotype. The distinctive fur pattern and the unstable allele of hypomorphic ch is caused by the temperature of the surrounding.

i'd say that the moon rock is about 2.2 billion years old.