Summary
Producing a genetically identical organism or cell, as with Dolly the sheep by nuclear transfer.
In depth
Reproductive cloning transfers a somatic nucleus into an enucleated egg (SCNT); Dolly in 1996. Efficiency is low and clones often have health problems. Therapeutic cloning aims to derive stem cells matched to a patient.
Reprogramming of the donor nucleus involves erasing epigenetic marks. Therapeutic cloning is limited by technical and ethical problems; iPSCs have largely replaced it.
Key idea: nuclear transfer proves differentiated cells retain all genes.
Cloning produces genetically identical copies. Natural clones include bacteria dividing, plants propagating by runners and identical twins. Molecular cloning copies DNA fragments, and reproductive cloning creates animals.
Somatic cell nuclear transfer replaces an egg's nucleus with one from a donor body cell. The first mammal cloned from an adult cell, Dolly (1996), was born after 277 attempts. Clones may show early ageing or developmental abnormalities due to incomplete epigenetic reprogramming. Therapeutic cloning aims to derive stem cells matched to a patient.
Example: cattle and horses are cloned commercially.
Common mistake: assuming clones are identical in personality; environment and chance shape development.
Frequently asked questions
What is Cloning?
Producing a genetically identical organism or cell, as with Dolly the sheep by nuclear transfer.
Which area of biology covers Cloning, and how advanced is it?
Cloning is one of the 54 topics in Developmental Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Totipotency, Growth, Induced Pluripotent Stem Cells.
Can you give an example of Cloning?
In 2018, macaques were cloned for the first time by SCNT.
What should I learn before Cloning?
Work through the Beginner topics in Developmental Biology first, such as Fertilisation, Zygote, Embryo, then return to Cloning. Intermediate topics assume the Beginner vocabulary.
What topics are related to Cloning?
The closest topics to Cloning are Totipotency, Growth, Induced Pluripotent Stem Cells, Reprogramming and Transdifferentiation. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cloning?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cloning. To practise the whole of Developmental Biology, use the Developmental Biology quiz.
How is Cloning different from Totipotency?
Cloning: Producing a genetically identical organism or cell, as with Dolly the sheep by nuclear transfer. Totipotency: The ability of a cell to give rise to all cell types, including embryonic and extraembryonic tissue. Read both side by side and note what each one explains.
What is a common mistake about Cloning?
Assuming clones are identical in personality; environment and chance shape development.
How should I study Cloning step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Totipotency and explain the difference aloud. Finally, take the Developmental Biology quiz and come back to this page for any question you miss.