Cloning Quiz
Questions: 16 · 10 minutes
1. A researcher has joined a DNA fragment to a plasmid. Which next step most directly allows separate populations containing copies of that construct to be established?
Transfer the plasmid into an enucleated mammalian egg
Use sperm to fertilize the plasmid-containing sample
Introduce the plasmid into host cells and select individual colonies
Split the DNA fragment into identical embryos
2. Why is an egg usually enucleated before receiving a somatic-cell nucleus in nuclear-transfer cloning?
To remove all mitochondria from the egg
To prevent the donor nucleus from producing proteins
To make fertilization by sperm occur more easily
To remove the egg's nuclear chromosomes before adding the donor genome
3. A lab claims an animal was produced by transferring a donor-cell nucleus into an enucleated egg. Which genetic pattern would best support that account?
Nuclear markers match the cell donor, while mitochondrial markers mainly match the egg donor
Nuclear markers are an equal mixture from the cell donor and egg donor
Nuclear markers match the egg donor, while mitochondrial markers match the nucleus donor
Both nuclear and mitochondrial markers match only the surrogate that carried the pregnancy
4. Two plants are cloned from the same parent, but one grows taller because it receives more light. What best explains the difference?
Cloning guarantees similar appearance only during early growth
One plant stops being a clone when its growth rate changes
The taller plant must have inherited DNA from a second parent
Environmental conditions can produce different traits despite shared genetics
5. A donor cell contains a mutation acquired during the donor animal's lifetime. What could happen if that nucleus is used for somatic cell nuclear transfer?
The egg automatically replaces every acquired mutation with its original sequence
The mutation may be carried in the clone's nuclear genome
The mutation can be inherited only if it is located in mitochondrial DNA
The mutation prevents the transferred nucleus from containing chromosomes
6. Scientists clone a few surviving members of an endangered species. Which limitation would cloning alone fail to solve?
The need for DNA inside each new animal's cells
A lack of genetic diversity among the remaining animals
The inheritance of any nuclear genes from the donor
The ability of cells to divide during development
7. Why might a clone differ biologically from its nuclear-DNA donor even when their nuclear sequences are very similar?
The clone receives half of its nuclear chromosomes from the egg donor
Gene regulation, developmental conditions, and incomplete epigenetic reprogramming can create differences
The donor's nuclear DNA is discarded once the embryo begins dividing
Every cell division deliberately creates a new species-specific genome
8. Which method was used to create Dolly the sheep?
Transferring an adult somatic-cell nucleus into an enucleated egg
Editing a fertilized egg to contain selected sheep genes
Splitting a naturally fertilized embryo into several embryos
Fertilizing an egg with sperm from a genetically related sheep
9. A DNA fragment is inserted into a plasmid, introduced into bacteria, and copied as the bacteria form colonies. What does this illustrate?
Reproductive cloning
Embryo splitting
Molecular cloning
Therapeutic cloning
10. Researchers separate the cells of a very early embryo so that each can develop as a genetically similar embryo. Which process are they using?
Embryo splitting
Somatic cell nuclear transfer
Gene editing
Selective breeding
11. What is the main research goal of therapeutic cloning?
To produce a genetically matched individual who develops to birth
To combine complete genomes from two different species
To copy DNA fragments by repeatedly heating and cooling a sample
To derive genetically matched cells that may be studied or used in regenerative research
12. How does PCR generally differ from traditional plasmid-based molecular cloning?
PCR amplifies a selected DNA region through repeated reactions in a tube without requiring a cellular host or plasmid vector
PCR creates a complete organism from a single adult cell
PCR copies DNA only after it has been inserted into a bacterial chromosome
PCR requires an enucleated egg to reproduce a DNA sequence
13. In biology, what is a clone?
Any organism produced without human assistance
A cell, DNA molecule, or organism produced with the same genetic information as a source
An organism whose genes have all been deliberately edited
A hybrid produced by combining two different species
14. A cloned cat has a coat pattern similar to its donor but develops different habits and preferences. Which explanation is most scientifically sound?
Clones share no meaningful genetic similarity after birth
Cloning copies learned memories but not behavioral tendencies
Development, experience, and gene regulation can influence behavior and appearance
Any behavioral difference proves that the cloning procedure failed
15. A scientist places the nucleus of a skin cell into an egg whose nucleus has been removed. If development begins, where do most nuclear DNA and mitochondrial DNA come from?
Both forms of DNA are newly assembled during development
Both nuclear and mitochondrial DNA come entirely from the skin-cell donor
Nuclear DNA comes from the egg donor, while mitochondrial DNA comes from the skin-cell donor
Nuclear DNA comes from the skin-cell donor, while mitochondrial DNA mainly comes from the egg donor
16. Which is a naturally occurring example of organismal cloning?
Fraternal twins developing from two separately fertilized eggs
Offspring produced by two closely related parents
Identical twins developing after one embryo splits
A hybrid plant produced by crossing two varieties