All of the offspring produced in a test cross involving a brown rabbit and a white rabbit are brown. The result of this cross is best explained by A. Incomplete dominance B. Codominance C. Crossing over D. Dominance

D

Explanation:

The result of the cross is best explained by dominance.

According to Mendel, when the alleles that make up a gene are different and one of the alleles is dominant over the other, the dominant allele would mask the effects of the recessive allele.

In the same vein, when the alternate version of the same trait is dominant, such trait would be expressed over the other version in heterozygous state.

Assuming that the genotype of the brown rabbit is BB and that of the white is bb. When the two rabbits are crossed:

     BB   x   bb

Bb   Bb   Bb   Bb

All the offspring would be heterozygous and brown in color because the brown allele is dominant over the white allele.

Hence, the correct option is D.

amber has allowed scientists to study dna that has been preserved over millions of years.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.