It took three sheep to create the clone Dolly: A blackface sheep donated the egg, a whiteface sheep donated the mammary cells from which the nucleus was taken, and a blackface sheep served as surrogate. Assuming face color is genetically determined, what color face did Dolly have?

Verified step by step guidance

1. Identify the source of the genetic material: Understand that the nucleus, which contains the genetic material determining traits such as face color, was taken from a whiteface sheep.
2. Recognize the role of the egg donor: Note that the egg from the blackface sheep had its nucleus removed, so it did not contribute genetic information regarding face color.
3. Consider the role of the surrogate: Acknowledge that the surrogate blackface sheep provided the environment for the embryo to develop but did not contribute genetically to traits such as face color.
4. Combine the information: Since the nucleus containing the genetic material came from a whiteface sheep, and the egg's nucleus was removed, the genetic traits including face color would be determined by the nucleus donor.
5. Conclude the face color of Dolly: Based on the origin of the nucleus, infer that Dolly, the cloned sheep, had the face color of the nucleus donor, which was white.

Key Concepts

Cloning

Cloning is a biotechnological process that creates a genetically identical copy of an organism. In the case of Dolly the sheep, somatic cell nuclear transfer (SCNT) was used, where the nucleus from a donor cell is transferred into an egg cell that has had its nucleus removed. This process allows the cloned organism to inherit the genetic material from the donor nucleus.

Genetic Determination of Traits

Genetic determination refers to how specific traits, such as physical characteristics, are controlled by genes. In this scenario, the color of the sheep's face is likely determined by the alleles present in the genetic material. Since Dolly was cloned from the mammary cells of a whiteface sheep, her face color would reflect the genetic information from that nucleus.

Somatic Cell Nuclear Transfer (SCNT)

Somatic Cell Nuclear Transfer (SCNT) is a method used in cloning where the nucleus of a somatic cell is transferred into an enucleated egg cell. This technique was pivotal in creating Dolly, as it allowed the genetic material from the whiteface sheep to dictate the traits of the clone, including face color, while the egg donor and surrogate contributed no genetic information.