CRISPR and reproductive screening
Do now
Explain how CRISPR-Cas9 edits DNA, including off-target risk, and apply it to a reproductive screening case.
- Hand in
- Annotated CRISPR article (guide RNA, Cas9 cut, repair step marked; off-target defined) plus a CER on using CRISPR in the reproductive screening case.
- Where
- Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
You get two school days for every day you were absent, so this deadline moves with you.
aims its cut with a short guide RNA about 20 letters long. If the human genome has 3 billion letters, how often will that guide accidentally match the wrong spot, and what breaks when it does?
Explain how edits DNA, including risk, and apply it to a reproductive screening case.
- • You'll be able to explain editing and risk.
- • You'll be able to apply limits to a reproductive case.
- What is the job of the guide RNA in , and what is the job of the Cas9 ?
- Why might a 20-letter guide sometimes match more than one place in a genome of 3 billion letters?
- 1Annotate the assigned article, marking the guide RNA, the Cas9 cut, and the repair step.
- 2Define and explain in one line why it is a concern.
- 3Read the reproductive screening case and decide what could and could not ethically do.
- 4Write a CER claim about using in the case, with two pieces of evidence.
- 5Submit your annotation and reproductive screening CER as your daily evidence.
What did this day actually feel like?
CRISPR and reproductive screening
How CRISPR targets a specific sequence, then screening embryos, which is a different thing from editing and gets confused with it constantly.
Selection and modification are not the same act and the ethics of each are different.
Turned in: CER → Claim Evidence Reasoning folder
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
The same day, drawn.
How CRISPR targets a specific sequence, then screening embryos, which is a different thing from editing and gets confused with it constantly.
MR. MENDOZA
Somatic affects one person. Germline affects everyone descended from them, and none of them can consent.
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
🛠 Get unstuck · pick your level
🔑 Today's words · 5
Tap a word in the lesson for a plain meaning and one example. Recycled into next week's Do-Now.
Do the work · 80-minute blockfirst 5 min = hook▸
💡 Big idea: A short guide RNA can match more than one spot in a 3-billion-letter genome, so Cas9 can cut and break a gene that was keeping the cell safe.
- 0-8Hook headlines; introduce guide RNA, Cas9, and repair as three discrete steps
- 8-30Annotate article: mark guide RNA, Cas9 cut, repair step; define in margin
- 30-45Read reproductive screening case; note what could and could not ethically do
- 45-62Write CER claim about using in this case with two evidences
- 62-75: check that reasoning names one limit
- 75-80Submit annotation and CER; preview Friday ethics synthesis
- • Hook: Show a headline about curing sickle cell disease and one about an ; ask which story matters more for policy.
- • Why it matters: Reproductive screening cases ask clinicians to apply capabilities and limits to decisions about embryos.
- • Today's work: annotation first (so you understand the tool), then the case (so you apply the limits).
- • Exit goal: Annotated article and reproductive screening CER submitted before the bell.
- • uses a guide RNA to direct the Cas9 endonuclease to a specific genomic address; Cas9 cuts both DNA strands.
- • The cell repairs the cut via NHEJ (often creating insertions/deletions) or HDR (if a repair template is supplied); HDR enables precise edits.
- • edits occur when the guide RNA matches non-target sequences well enough to direct a cut; this can disrupt -suppressor genes or other critical loci.
Gene therapy, viral vectors, somatic vs. germline editing, CRISPR basics, reproductive screening. · and reproductive screening
Day 3 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.
Do this: Open Activity 2.2.1 in myPLTW and complete the genome editing activity alongside the reproductive screening case.
Mark the activity complete after your annotation and CER are submitted.
Vector chart should be done (Tuesday); annotation and CER due today.
Annotated article and reproductive screening CER submitted on the class site.
The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Gene therapy, viral vectors, somatic vs. germline editing, CRISPR basics, reproductive screening. · CRISPR and reproductive screening
Open Activity 2.2.1 in myPLTW and complete the genome editing activity alongside the reproductive screening case.
Vector chart should be done (Tuesday); annotation and CER due today.
This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.
🎯 Explain how edits DNA, including risk, and apply it to a reproductive screening case.
- Annotate the assigned article, marking the guide RNA, the Cas9 cut, and the repair step.
- Define and explain in one line why it is a concern.
- Read the reproductive screening case and decide what could and could not ethically do.
- Write a CER claim about using in the case, with two pieces of evidence.
- Submit your annotation and reproductive screening CER as your daily evidence.
CER: Annotated article (guide RNA, Cas9 cut, repair step marked; defined) plus a CER on using CRISPR in the reproductive screening case.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.
| Task | Who |
|---|---|
| Annotate the assigned article, marking the guide RNA, the Cas9 cut, and the repair step. | _______ |
| Define and explain in one line why it is a concern. | _______ |
| Read the reproductive screening case and decide what could and could not ethically do. | _______ |
| Write a CER claim about using in the case, with two pieces of evidence. | _______ |
| Submit your annotation and reproductive screening CER as your daily evidence. | _______ |
Working solo? Put your own name in "Who" for every row.
- You'll be able to explain editing and risk.
- You'll be able to apply limits to a reproductive case.
- 1Do thisExplain how CRISPR-Cas9 edits DNA, including off-target risk, and apply it to a reproductive screening case.
- 2Use this resource
- 3Submit thisCER: Annotated CRISPR article (guide RNA, Cas9 cut, repair step marked; off-target defined) plus a CER on using CRISPR in the reproductive screening case.
- 4Submit it here
- 1Open the drop folder.
- 2Sign in with your district Microsoft account, not a personal one.
- 3Upload the file, named Lastname_Firstname__Assignment Title.
- 4Your own upload panel says Uploaded with a green check: that is your receipt.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Genetics of Disease (Medical Interventions) › Gene therapy, viral vectors, somatic vs. germline editing, CRISPR basics, reproductive screening. › CEROpen the drop folder
Learn it · deck, reading, and vocabulary▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Generated from this lesson's canonical data with a red-team citation check.
Engineers gut a virus of its disease genes but keep its cell-entry machinery, so the same tool that once caused infection can now deliver a cure.
A short guide RNA can match more than one spot in a 3-billion-letter genome, so Cas9 can cut and break a gene that was keeping the cell safe.
A library keeps a master plan protected while working copies guide production at different stations.
- Why protect the master copy?
- What information moves?
- Where can an error change the final product?
Stored information can be copied, read, and converted into a functional product.
Genes are regulated biological sequences, not conscious instructions, and one gene rarely determines a whole trait alone.
- • Master plan maps to DNA.
- • Working copy maps to RNA.
- • Production output maps to or a regulated cell function.
Driving question: aims its cut with a short guide RNA about 20 letters long. If the human genome has 3 billion letters, how often will that guide accidentally match the wrong spot, and what breaks when it does?
What you already know: Engineers gut a virus of its disease genes but keep its cell-entry machinery, so the same tool that once caused infection can now deliver a cure.
New idea: A short guide RNA can match more than one spot in a 3-billion-letter genome, so Cas9 can cut and break a gene that was keeping the cell safe.
Visual or model: F1. F1. A lesson illustration or teaching diagram for CRISPR and reproductive screening. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled testing, treatment, or biological process and identify where evidence limits the decision.
- Observe or measure the relevant feature in and reproductive screening.
- Organize the observation with a stable evidence ID.
- Apply this rule: Stored information can be copied, read, and converted into a functional product.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: aims its cut with a short guide RNA about 20 letters long. If the human genome has 3 billion letters, how often will that guide accidentally match the wrong spot, and what breaks when it does?
What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • : Treating disease by adding, silencing, or correcting a gene in a patient's cells.
- • vector: A that delivers genetic material into a cell, such as a or virus, or an organism like a mosquito that spreads a disease.
- • : A gene-editing tool that uses a guide RNA to steer the Cas9 to a chosen DNA site and cut it, so a sequence can be changed.
- • : Relating to the ordinary body cells other than egg and sperm; changes in these cells affect only the individual and are not inherited.
- • : The egg, sperm, and the cells that make them; changes in these cells can be passed to a person's children.
- • : An unintended effect when a drug or gene-editing tool acts on something other than its intended target, which can cause side effects.
- • : Agreeing to a treatment or study only after truly understanding its purpose, risks, benefits, and alternatives; the understanding, not the signature, is the ethics.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
uses a guide RNA to direct the Cas9 endonuclease to a specific genomic address; Cas9 cuts both DNA strands.
Limit: E1 supplies context or an observation; it does not by itself establish the explanation.
A short guide RNA can match more than one spot in a 3-billion-letter genome, so Cas9 can cut and break a gene that was keeping the cell safe.
Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.
You'll be able to explain editing and risk.
Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.
PLTW-GEND-2026-10-28 · Simulated classroom evidence scenario
Your role: medical interventions team member
Decision: Your team must decide what the evidence from and reproductive screening supports before submitting the claim-evidence-reasoning response named on the lesson page.
- • Choose the strongest supported explanation.
- • Choose the next evidence to collect.
- • Hold the decision because the evidence is insufficient.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the claim-evidence-reasoning response.
Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about and reproductive screening. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
Reason for review: Your team must decide what the evidence from and reproductive screening supports before submitting the claim-evidence-reasoning response named on the lesson page.
Context: Precision is a feature, not a bonus; molecular scissors that cut in the wrong place can break a gene that was protecting the cell, so how exactly they aim is a matter of life and death.
- • T1: Annotate the assigned article, marking the guide RNA, the Cas9 cut, and the repair step.
- • T2: Define and explain in one line why it is a concern.
- • T3: Read the reproductive screening case and decide what could and could not ethically do.
- • T4: Write a CER claim about using in the case, with two pieces of evidence.
- • T5: Submit your annotation and reproductive screening CER as your daily evidence.
- • E1: uses a guide RNA to direct the Cas9 endonuclease to a specific genomic address; Cas9 cuts both DNA strands.
- • E2: A short guide RNA can match more than one spot in a 3-billion-letter genome, so Cas9 can cut and break a gene that was keeping the cell safe.
- • E3: You'll be able to explain editing and risk.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Figure finding: Teaching diagram for and reproductive screening. Trace the labeled testing, treatment, or biological process and identify where evidence limits the decision. This is a teaching model, not patient or experimental data.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
Mean = sum of values / number of values. Median = middle ordered value. Range = maximum - minimum.
For 2, 4, 4, and 10: mean = 20 / 4 = 5, median = 4, and range = 10 - 2 = 8.
Mean, median, and range keep the measurement unit. Order the values before finding the median.
Calculate the requested summary for today's supplied values, then write what it reveals and what it hides.
Students often think Students often think is perfectly precise, so if it is targeted, it must only ever cut the exact right gene.. The trap: is not flawless, because the guide RNA can match near-identical sequences elsewhere and direct Cas9 to cut there too. That cut is the trap: precise does not mean perfect, and a wrong cut in a -suppressor gene can cause real harm.
Parallel case: A 16-year-old with severe sickle cell disease is offered a CRISPR-based therapy. Doctors would remove some of the patient's own bone-marrow stem cells, use a guide RNA to steer Cas9 to a single gene (BCL11A) that switches off fetal hemoglobin, cut that gene, and let the cells' repair machinery disable it. The edited cells are grown and returned to the patient so their body makes protective fetal hemoglobin again. The patient and their guardians consent after counseling.\n\nClaim: In this case CRISPR-based somatic therapy is an appropriate treatment to offer, because the edit is limited to the patient's own body cells, is not passed to future generations, and is chosen with informed consent to treat serious ongoing harm.\n\nEvidence 1: The edit is somatic, not germline. It changes blood-forming cells in one person and is not inherited by that person's future children, so any mistake affects only the consenting patient and does not spread to descendants.\n\nEvidence 2: Off-target risk is real but is being managed and consented to. The guide RNA is about 20 letters long against a genome of roughly 3 billion letters, so Cas9 can cut a wrong site that partially matches, and a bad off-target cut could disrupt a tumor suppressor or another important gene. However, the edited cells can be screened before they are returned, and the patient is weighing that known risk against the daily harm of untreated sickle cell disease.\n\nReasoning: Because the change stays in one consenting person and is not heritable, the ethical stakes are lower than a change that every future generation would carry. The off-target danger does not disappear, but it can be reduced by checking the cells and is being accepted knowingly to relieve a serious, present illness. When a competent patient consents, the harm is severe, and the risk is bounded to that individual, offering the somatic edit is justified.
This model shows the level of evidence and organization needed to complete: Models the CER format on a parallel gene-editing case: a claim, two pieces of evidence, and reasoning about whether to use CRISPR-based somatic therapy in a consenting teenage patient with sickle cell disease. This mirrors the structure and depth students must produce today without answering the embryo screening prompt.
- Write one defensible claim.
- Choose specific evidence that supports the claim.
- Explain the scientific rule that connects the evidence to the claim.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Submit your annotation and reproductive screening CER to the class site.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in CRISPR and reproductive screening. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Classroom documents for this lesson are posted in Schoology. Open Clever, then Schoology, and find each one by the name shown on its card.
Use this if you were absent, got stuck, or need another pass before you submit the lesson artifact.
Placement rationale
Matched , , reproductive ethics by path:Medical-Interventions/Unit-2_How-to-Screen-Your-Genes/2.2_Our-Genetic-Future; keywords:gene therapy, reproductive. Score 138. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
Open this when the class reaches this activity and use it to complete the required lesson artifact.
Placement rationale
Matched , , reproductive ethics by path:Medical-Interventions/Unit-2_How-to-Screen-Your-Genes/2.2_Our-Genetic-Future; keywords:ethics, reproductive. Score 138. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
Use this after the required lesson work when you are ready for a harder application or a deeper connection.
Placement rationale
Matched , , reproductive ethics by path:Medical-Interventions/Unit-2_How-to-Screen-Your-Genes/00_Unit-Overview; keywords:gene therapy, crispr. Score 134. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
How to get there: open Clever and sign in with your Microsoft (district) account. Both myPLTW and Schoology are in Clever. Do the activity in myPLTW. Turn the work in on this site or hand it to Mr. Mendoza, because that is the step that counts as submitted. Schoology only shows your report-card grade later.
Check yourself · commit, then reveal▸
Claim ceiling for this check: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about and reproductive screening. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
After Cas9 cuts the DNA, the cell can repair it by NHEJ or HDR. Which one gives a precise, intended edit, and what does it require?
Write an answer and pick a confidence to unlock the key.
Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.
Go further and get help▸
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
Today is individual work you can do from home: complete the same target above, then submit your CER.
Open the drop folderTurn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
MedlinePlus: What is gene therapy?You've passed Unit 2, so the optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.
Open the extra-credit track- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedTurned in the right way, on the class site or handed to Mr. Mendoza in class, and confirmed. Not in Schoology: that is where the report-card grade appears later.