You obtain an egg cell from the ovary of a white mouse and remove the nucleus from it. You then obtain a nucleus from a liver cell from an adult black mouse. You use the methods of nuclear transplantation to insert the nucleus into the empty egg. After some prompting, the new zygote divides into an early embryo, which you then implant into the uterus of a brown mouse. A few weeks later, a baby mouse is born. What color will it be? Why?

Verified step by step guidance

1. Identify the source of the genetic material: In this scenario, the nucleus, which contains the genetic material determining many characteristics including fur color, is taken from a liver cell of a black mouse.
2. Understand the role of the egg cell: The egg cell from the white mouse has had its nucleus removed, so it does not contribute genetic information to the offspring, but provides the cellular machinery necessary for development.
3. Recognize the process of nuclear transplantation: This technique involves inserting a nucleus from one cell (in this case, from the black mouse) into an enucleated egg cell (from the white mouse). The genetic information in the transplanted nucleus will direct the development of the mouse.
4. Consider the role of the surrogate mother: The brown mouse serves as the surrogate mother, providing a nurturing environment for the embryo to develop. However, the surrogate mother does not contribute genetically to the color of the fur of the offspring.
5. Conclude the likely fur color of the offspring: Since the genetic information comes from the black mouse, and the egg cell and surrogate mother do not contribute genetically to the fur color, the baby mouse is likely to be black.

Key Concepts

Nuclear Transplantation

Nuclear transplantation is a technique where the nucleus of a donor cell is transferred into an enucleated egg cell. This process allows the egg to develop into an embryo using the genetic material from the donor nucleus. In this scenario, the nucleus from a black mouse's liver cell is inserted into the egg cell of a white mouse, which is crucial for understanding the genetic outcome of the resulting organism.

Genetic Expression and Phenotype

The phenotype of an organism, such as its color, is determined by the expression of genes inherited from its parents. In this case, the black mouse's liver cell nucleus carries the genetic information that will dictate the color of the offspring. Since the nucleus from the black mouse is responsible for the genetic traits, the resulting baby mouse will exhibit the phenotype associated with the black mouse's genes.

Maternal Influence on Development

While the genetic material from the black mouse determines the offspring's traits, the environment provided by the surrogate mother (the brown mouse) can also influence development. However, in this case, the color of the baby mouse will primarily reflect the genetic information from the nucleus of the black mouse, as the egg's cytoplasm does not contribute to the genetic makeup but can affect early development.