Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 11 How Genes Are Controlled
Taylor - Campbell Biology: Concepts & Connections 10th Edition
Taylor, Simon, Dickey, Hogan10th EditionCampbell Biology: Concepts & ConnectionsISBN: 9780136538783Not the one you use?Change textbook
Chapter 11, Problem 13

Each scientist works as part of a broader community of scientists, building on the work of others. Scientific advances often depend on the application of new technologies and/or on new techniques applied to an existing problem.
What improvements to existing cloning methods did Wilmut make that allowed him to successfully clone Dolly the sheep from an adult cell?

Verified step by step guidance
1
Understand the context of cloning: Cloning involves creating a genetically identical copy of an organism. In the case of Dolly the sheep, the process used was somatic cell nuclear transfer (SCNT), which involves transferring the nucleus of a somatic (body) cell into an enucleated egg cell.
Recognize the challenge Wilmut addressed: Previous cloning attempts often used embryonic cells, which are more flexible and easier to reprogram. Wilmut's breakthrough was successfully cloning an organism using the nucleus from an adult somatic cell, which is more specialized and harder to reprogram.
Identify the key improvement: Wilmut and his team introduced a critical step of 'cell cycle synchronization.' They starved the donor somatic cells to induce them into a quiescent state (G0 phase of the cell cycle). This synchronization made the nucleus more receptive to reprogramming when transferred into the enucleated egg cell.
Understand the reprogramming process: After transferring the adult somatic cell nucleus into the enucleated egg, the egg was stimulated using electrical pulses to mimic fertilization. This step initiated the reprogramming of the adult nucleus to behave like a zygote nucleus, capable of directing embryonic development.
Recognize the significance: Wilmut's method demonstrated that adult somatic cells could be reprogrammed to create a viable clone, paving the way for advancements in cloning technology and raising important ethical and scientific questions about the potential applications of cloning.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Somatic Cell Nuclear Transfer (SCNT)

Somatic Cell Nuclear Transfer is a cloning technique where the nucleus of a somatic cell is transferred into an enucleated egg cell. This process allows the egg to develop into an organism that is genetically identical to the donor of the somatic cell. Wilmut's successful cloning of Dolly the sheep utilized SCNT, which was pivotal in demonstrating that adult cells could be reprogrammed to develop into a new organism.
Recommended video:
Guided course
09:40
Introduction to Cell Division

Reprogramming of Adult Cells

Reprogramming refers to the process of reverting differentiated adult cells back to a pluripotent state, allowing them to develop into any cell type. Wilmut improved existing cloning methods by effectively reprogramming the adult somatic cell nucleus, which was crucial for overcoming the limitations of previous cloning attempts that primarily used embryonic cells.
Recommended video:
Guided course
01:47
Embryonic and Adult Tissues

Epigenetic Modifications

Epigenetic modifications are chemical changes to DNA and histone proteins that affect gene expression without altering the underlying DNA sequence. These modifications play a significant role in cellular differentiation and development. Wilmut's advancements in cloning involved understanding and manipulating these epigenetic factors to ensure that the cloned embryo developed properly, reflecting the characteristics of the adult donor.
Recommended video:
Guided course
04:26
Post-Translational Modification
Related Practice
Textbook Question

Mutations can alter the function of the lac operon (see Module 11.1). Predict how the following mutations would affect the function of the operon in the presence and absence of lactose:

a. Mutation of the regulatory gene; repressor cannot bind to lactose.

b. Mutation of operator; repressor will not bind to operator.

c. Mutation of regulatory gene; repressor will not bind to operator.

d. Mutation of promoter; RNA polymerase will not attach to promoter.

2514
views
Textbook Question

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?

1408
views
Textbook Question

The success of an experiment often depends on choosing an appropriate organism to study. For example, Gregor Mendel was able to deduce the fundamental principles in genetics in part because of his choice of the pea plant. Reviewing Module 10.1, how did Hershey and Chase take advantage of the unique structural properties of bacteriophage T2 to determine the genetic material?

1094
views
Textbook Question
Scientific Thinking The study described in Module 8.10 was purely observational; there were no controlled groups. Imagine that you are an oncologist. Design a hypothesis-driven study to determine whether mastectomy improves breast cancer survival over lumpectomy. What are your control groups? Would such a study be ethical to undertake? Why or why not?
1450
views