Biology • Year 12 • Module 6 • Lesson 15
Cloning — Whole Organism and Gene Cloning
Lock in the two definitions, the vector–host process for gene cloning, and the honest language for assessing effectiveness — so you stop calling all cloning "perfect copying".
1. Term–definition match
Match each definition (shuffled) to the correct term from this list: clone, whole-organism cloning, gene cloning, vector, host cell, somatic-cell nuclear transfer (SCNT), enucleated egg, plasmid, recombinant DNA, effectiveness. 10 marks
| # | Definition (shuffled) | Matching term |
|---|---|---|
| 1.1 | Making many identical copies of a selected DNA sequence using a vector and a host cell. | |
| 1.2 | A genetically identical copy of DNA, a cell or — in some cases — a whole organism. | |
| 1.3 | A small circular DNA molecule from a bacterium, used to carry foreign DNA into a host cell. | |
| 1.4 | Production of an organism with a genome intended to match that of a donor organism. | |
| 1.5 | A DNA carrier (e.g. a plasmid or virus) used to transfer a chosen gene into a host cell. | |
| 1.6 | A cell used to replicate inserted DNA, or to express a product (such as a protein) from it. | |
| 1.7 | An egg cell from which the original nucleus has been removed before another nucleus is inserted. | |
| 1.8 | The technique of inserting a nucleus from a donor body cell into an enucleated egg — the method used to produce Dolly the sheep. | |
| 1.9 | DNA made by joining sequences from two or more sources, often a target gene inserted into a vector. | |
| 1.10 | How well a process actually achieves its intended purpose — judged against success rate, usefulness and limitations, not just whether a copy was made. |
2. True or false — with correction
For each statement, circle T or F. If the statement is false, write the corrected version. 10 marks (1 for T/F, 1 for the correction where needed)
2.1 Whole-organism cloning and gene cloning are the same process applied at different scales. T / F
2.2 Gene cloning produces many copies of a selected DNA sequence by inserting it into a vector and replicating it in a host cell. T / F
2.3 A whole-organism clone is guaranteed to have an identical phenotype to its donor under all conditions. T / F
2.4 In somatic-cell nuclear transfer, the nucleus of a donor body cell is placed into an egg cell whose nucleus has been removed. T / F
2.5 A plasmid is an animal cell organelle that produces gametes. T / F
3. Function recall
Answer each in 1–2 sentences using precise terms from the lesson. 10 marks (2 each)
3.1 What is the function of a vector (such as a plasmid) in gene cloning?
3.2 What is the function of a host cell in gene cloning?
3.3 What is the function of removing the nucleus from an egg cell before transferring a donor nucleus in whole-organism cloning?
3.4 What is the function of the surrogate in mammalian whole-organism cloning?
3.5 What is the function of assessing effectiveness by goal rather than asking "did any copying happen?"
4. Sequence the gene-cloning workflow
The seven steps below are shuffled. In the "Order" column write a number 1–7 showing the correct sequence for a typical gene-cloning workflow. 7 marks
| Step | Event (shuffled) | Order |
|---|---|---|
| 4.1 | The host cell divides repeatedly; each daughter cell contains a copy of the recombinant DNA. | |
| 4.2 | A target gene of interest (e.g. the human insulin gene) is identified and isolated. | |
| 4.3 | The recombinant vector is introduced into a host cell, such as a bacterial cell. | |
| 4.4 | The target gene is inserted into a vector (e.g. a bacterial plasmid) to form recombinant DNA. | |
| 4.5 | Many identical copies of the gene (and any encoded protein) are harvested from the cultured host cells. | |
| 4.6 | Host cells that successfully took up the recombinant vector are selected and grown in culture. | |
| 4.7 | The vector is opened (e.g. cut with a restriction enzyme) so the target gene can be ligated in. |
5. Fill the blanks — comparison paragraph
Fill each blank using terms from the word bank. Each term is used at most once. 9 marks
Word bank: selected DNA sequence • genotype • phenotype • enucleated • somatic • plasmid • host cell • surrogate • effectiveness • biotechnology
Whole-organism cloning aims to produce an organism whose nuclear (5.1) _______________________ matches that of a donor. In somatic-cell nuclear transfer, the nucleus of a donor (5.2) _______________________ cell is inserted into an (5.3) _______________________ egg, and the reconstructed cell is implanted into a (5.4) _______________________ for development. Even when the technique succeeds, the resulting (5.5) _______________________ is not guaranteed to be identical to the donor's, because development and environment also influence it.
Gene cloning is a separate process. A (5.6) _______________________ is inserted into a vector — commonly a bacterial (5.7) _______________________ — and the recombinant DNA is taken up by a (5.8) _______________________, which then replicates it many times. Because the goal is narrow and controllable, gene cloning's (5.9) _______________________ is often easier to justify, and it underpins much of modern _______________________.
6. Compare-and-contrast table
Complete the table below by writing the correct feature for whole-organism cloning and for gene cloning. Use lesson terms. 8 marks (1 per cell)
| Feature | Whole-organism cloning | Gene cloning |
|---|---|---|
| What is copied (level of biology)? | ||
| Key cellular technique used | ||
| Typical efficiency / success rate | ||
| Main use(s) |
Q1 — Term–definition matches (10 marks)
1.1 gene cloning • 1.2 clone • 1.3 plasmid • 1.4 whole-organism cloning • 1.5 vector • 1.6 host cell • 1.7 enucleated egg • 1.8 somatic-cell nuclear transfer (SCNT) • 1.9 recombinant DNA • 1.10 effectiveness. 1 mark per correct match.
Q2 — True / false with correction (10 marks)
2.1 False. Correction: they are different processes. Whole-organism cloning copies organism-level genotype using nuclear transfer; gene cloning copies a selected DNA sequence using a vector and host cell.
2.2 True.
2.3 False. Correction: even when nuclear genotype is matched, phenotype is also shaped by development and environment, so identical phenotype under all conditions is not guaranteed.
2.4 True.
2.5 False. Correction: a plasmid is a small circular DNA molecule found in bacteria, used as a vector in gene cloning. It is not an organelle and does not produce gametes.
Q3 — Function recall (10 marks, 2 each)
3.1 The vector's function is to carry the chosen DNA sequence into a host cell and ensure it is replicated as the host cell divides. Plasmids work well because they are small, circular and replicate independently of the host chromosome.
3.2 The host cell's function is to receive the recombinant DNA and copy it many times during its own replication, and (in many applications) to express the inserted gene as a useful protein product.
3.3 Removing the egg's nucleus prevents the egg's own DNA from contributing to the offspring, so that the nuclear genetic information of the clone comes (essentially) from the donor body cell, not from the egg donor.
3.4 The surrogate's function is to provide a uterine environment in which the reconstructed embryo can develop to term; the surrogate contributes the gestational environment but not the nuclear genotype.
3.5 Assessing by goal forces students to ask "did the process achieve its intended purpose at an acceptable success rate?" This separates whole-organism cloning (low efficiency, no phenotype guarantee) from gene cloning (specific narrow goal, often highly effective), preventing the lazy claim that "all cloning is the same".
Q4 — Sequenced gene-cloning workflow (7 marks)
Correct order: 4.2 → 4.7 → 4.4 → 4.3 → 4.6 → 4.1 → 4.5.
- 4.2 Identify and isolate the target gene of interest.
- 4.7 Open the vector using a restriction enzyme so the gene can be inserted.
- 4.4 Insert the target gene into the vector to form recombinant DNA.
- 4.3 Introduce the recombinant vector into a host cell (e.g. bacterium).
- 4.6 Select host cells that took up the recombinant vector and culture them.
- 4.1 Host cells divide repeatedly; each daughter inherits a copy of the recombinant DNA.
- 4.5 Harvest the many identical copies of the gene (and any encoded protein).
1 mark per correctly placed step.
Q5 — Cloze paragraph (9 marks)
5.1 genotype • 5.2 somatic • 5.3 enucleated • 5.4 surrogate • 5.5 phenotype • 5.6 selected DNA sequence • 5.7 plasmid • 5.8 host cell • 5.9 effectiveness. (The final "biotechnology" was given to the student; the nine numbered blanks are the marked items.)
Q6 — Compare-and-contrast table (8 marks)
| Feature | Whole-organism cloning | Gene cloning |
|---|---|---|
| What is copied | The nuclear genotype of a whole organism (organism-level copy). | A selected DNA sequence / single gene (gene-level copy). |
| Key cellular technique | Somatic-cell nuclear transfer (SCNT) into an enucleated egg, implanted into a surrogate. | Insertion of the gene into a vector (e.g. plasmid), then uptake and replication in a host cell. |
| Typical efficiency | Low — many embryos fail to develop; success rates per attempt are usually very low. | High — once the vector is in the host, replication is reliable and scalable. |
| Main uses | Preserve or reproduce a valuable genotype (research animals, livestock, limited conservation use). | Make many copies of DNA for analysis, sequencing, and production of useful proteins (e.g. insulin). |
1 mark per correctly completed cell.