Emma and anna are identical twins who were adopted by different families a few weeks after birth. although genetically identical, they grew up with different physical and psychological characteristics. for example, though both inherited a tendency to grow large, anna was slim and athletic due to the active lifestyle practiced in her adoptive family. this variability can be explained by how: a. longevity genes can make an individual less vulnerable to certain diseases. b. for each genotype, a range of phenotypes can be expressed . c. each zygote is unique. d. mutated genes can be a source of genetic variability.

The correct answer is option B. for each genotype, a range of phenotypes can be expressed.

Explanation:

The genotype is the genetic makeup of an individual that expresses the one of its character that helps in making phenotype of the individual where is phenotype is the characteristics or traits expressed by the interaction of the genotype with the atmosphere around the individual.

Genotype interaction can express the different phenotypes in individuals even though they are genetically similar by birth.

Thus, the correct answer is option B. for each genotype, a range of phenotypes can be expressed.

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