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Science Grade 9-12 Answer Key

Science: Biotechnology and Bioethics CRISPR, Cloning, and GMOs

Exploring gene editing, cloning, genetically modified organisms, and ethical decision-making

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Science: Biotechnology and Bioethics CRISPR, Cloning, and GMOs

Exploring gene editing, cloning, genetically modified organisms, and ethical decision-making

Science - Grade 9-12

Instructions: Read each problem carefully. Use evidence and complete sentences when explaining your reasoning.
  1. 1

    Explain the main job of CRISPR-Cas9 in gene editing. Include the roles of the guide RNA and the Cas9 enzyme.

    Think of guide RNA as an address and Cas9 as molecular scissors.

    CRISPR-Cas9 edits DNA by using a guide RNA to find a matching DNA sequence and the Cas9 enzyme to cut the DNA at that location. After the cut, the cell may repair the DNA in a way that disables a gene or allows a new sequence to be added.
  2. 2

    A scientist wants to use CRISPR to treat a genetic blood disorder in a patient by editing bone marrow cells and returning them to the same patient. Is this somatic editing or germline editing? Explain your answer.

    Ask whether the edit can be passed from parent to child.

    This is somatic editing because the edited cells are body cells from the patient and the changes should not be passed to future children. Germline editing would involve sperm, eggs, or embryos and could be inherited.
  3. 3

    Describe one possible medical benefit and one possible risk of using CRISPR in humans.

    One possible benefit is that CRISPR could correct or reduce the effects of genetic diseases such as sickle cell disease. One possible risk is an off-target edit, where CRISPR changes DNA at an unintended location and causes harmful effects.
  4. 4

    In a CRISPR experiment, the intended DNA target sequence is found once in a genome, but a very similar sequence occurs elsewhere. Explain why this could be a safety concern.

    Consider what happens if molecular scissors cut the wrong page in an instruction book.

    This could be a safety concern because the guide RNA might also bind to the similar sequence. If Cas9 cuts the wrong location, the edit could disrupt an important gene or create an unexpected mutation.
  5. 5

    Compare reproductive cloning and therapeutic cloning. Give one key difference in their goals.

    Focus on the final outcome of each process.

    Reproductive cloning aims to create a new organism with nearly the same nuclear DNA as another organism. Therapeutic cloning aims to produce cells or tissues for research or medical treatment, not to create a full organism.
  6. 6

    A diagram shows a sheep body cell nucleus placed into an egg cell whose nucleus was removed. The egg begins dividing and is implanted into a surrogate sheep. What biotechnology process is being shown, and what is the likely genetic relationship between the lamb and the sheep that donated the body cell nucleus?

    The process is reproductive cloning by somatic cell nuclear transfer. The lamb would have nuclear DNA that is nearly identical to the sheep that donated the body cell nucleus, although mitochondrial DNA would come from the egg donor.
  7. 7

    List two reasons why cloning a beloved pet would not produce an exact copy of the original animal's personality or behavior.

    Genes matter, but they are not the only factor shaping traits.

    A cloned pet would not be an exact copy because environment, training, diet, social experiences, and random developmental events influence personality and behavior. The clone may share much of the same nuclear DNA, but it would not have the same life experiences.
  8. 8

    Define genetically modified organism, or GMO, in your own words. Give one example from agriculture.

    A genetically modified organism is an organism whose DNA has been changed using biotechnology to give it a desired trait. One agricultural example is corn engineered to resist certain insect pests.
  9. 9

    A GMO crop produces a protein that is toxic to a specific insect pest but not to humans. Identify one possible benefit and one possible ecological concern of planting this crop widely.

    Think about both farm productivity and ecosystem effects.

    One possible benefit is that farmers may use less chemical insecticide. One possible ecological concern is that pest populations may evolve resistance or that non-target organisms could be affected if the protein harms them.
  10. 10

    Golden Rice is engineered to produce beta-carotene, which the human body can convert into vitamin A. Explain how this GMO could help public health and identify one non-scientific factor that could affect whether it is used.

    Golden Rice could help public health by reducing vitamin A deficiency in populations that rely heavily on rice as a staple food. A non-scientific factor that could affect its use is public trust, cultural acceptance, cost, government regulation, or access for farmers.
  11. 11

    A farmer is deciding whether to plant an herbicide-tolerant GMO soybean variety. Explain one potential advantage for the farmer and one potential long-term problem if the same herbicide is overused.

    Repeated selection pressure can change populations.

    One potential advantage is easier weed control, which can save labor and protect crop yield. A potential long-term problem is that weeds may evolve herbicide resistance, making the herbicide less effective over time.
  12. 12

    Place these biotechnology steps in the correct order for making a transgenic plant: insert the gene into plant cells, identify a useful gene, grow whole plants from modified cells, confirm the trait is expressed.

    The correct order is to identify a useful gene, insert the gene into plant cells, grow whole plants from modified cells, and confirm the trait is expressed.
  13. 13

    Explain why informed consent is important in a human gene therapy trial.

    Patients should know what they are agreeing to before treatment or research begins.

    Informed consent is important because participants must understand the purpose, possible benefits, risks, alternatives, and limits of the trial before agreeing to take part. It protects patient autonomy and helps ensure the research is ethical.
  14. 14

    A company wants to edit embryos to reduce the chance of a serious inherited disease. Another company wants to edit embryos to increase adult height. Explain why society might view these two uses differently.

    Society might view disease prevention as a medical use that reduces suffering, while increasing height may be seen as enhancement rather than treatment. The enhancement use raises additional concerns about fairness, social pressure, inequality, and changing traits for non-medical reasons.
  15. 15

    Use the ethical principles of benefits, risks, fairness, and consent to evaluate whether a new GMO mosquito should be released to reduce malaria. Write a balanced response.

    A strong answer includes both possible public health benefits and possible community or environmental concerns.

    A balanced response should explain that the GMO mosquito could provide a major benefit by reducing malaria illness and deaths. It should also consider risks such as unintended ecological effects, fairness issues for communities most affected, and the challenge of getting meaningful public consent before release.
LivePhysics™.com Science - Grade 9-12 - Answer Key