Biology Regents Practice Exam

Why might replacement pets produced through cloning techniques not look or act like the original?

1. The new animal must get the DNA from two different parents, not just one cell.

2. Mutations could occur that change the cloned animal into a completely different species.

3. Recombination of the cells as they are cloned will make the resulting pet act differently.

4. The environment could influence how genes are expressed, changing how the animal looks and acts.

The correct answer is: The environment could influence how genes are expressed, changing how the animal looks and acts.

The correct answer highlights the role of the environment in shaping traits and behaviors in organisms, even when the genetic material is identical, as in the case of cloned animals. Cloning produces a new organism with the same DNA as the original, but that organism will develop and behave differently based on various environmental factors, such as diet, living conditions, social interactions, and experiences. These environmental influences can affect gene expression through processes like epigenetics, which can modify how genes are turned on or off without changing the underlying DNA sequence. In contrast, while the first choice discusses the requirement for genetic material from two parents, this is not applicable in the context of cloning, where one cell is used to create an organism. The second choice suggests that mutations could convert the clone into a different species, but mutations generally don’t create entirely new species overnight, especially in the context of cloning. The third option incorrectly implies that recombination during cloning affects behavior, but cloning typically does not involve recombination in the same sense as sexual reproduction; instead, it involves creating a genetic copy. Overall, the emphasis on environmental influences in the correct response accurately reflects a key principle in biology concerning the interaction between genetics and environment.