A self-test on mitosis, how fertilisation and meiosis give variation, and sex-linked inheritance (AC9S10U01, nodes 2, 5 and 6, taught in class; node 6 a hinge).
Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.
Node 2 4 min · Node 5 6 min · Node 6 6 min
A Quick check: a few questions on what students should know for AC9S10U01 nodes 2, 5 and 6, which you teach in class. It has no board, no clip and no new teaching, and it is optional, so it never holds up course completion. Set the width with ?width=minimum, typical (default) or wider.
Use it as a self-test after your teaching, a starter, or revision. DNA, meiosis and Punnett squares are on screen (nodes 1, 3 and 4). The notation here is XN for the normal allele and Xn for the condition allele; use whichever your class uses, as long as it is consistent.
Keeping the sex chromosomes and the alleles apart in one square. When a student gets lost, ask which letters are chromosomes and which are alleles.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student says mitosis makes gametes. | What is the chromosome number in a gamete? | Half. Mitosis keeps it the same, so gametes come from meiosis. |
| A student says a carrier mother has the condition. | Does she have a second, normal X? | Yes, which masks it, so she is a carrier, not affected. |
Stretch: Trace a trait such as red-green colour blindness through three generations of a family tree.
Support: Give the Punnett square grid with the parent gametes already written in.
For a student who has done the lesson and is still stuck. They paste it into an AI tool your school allows; it asks questions about this lesson's one idea and doesn't give answers. Students see it on the course recap page only through a link ending in ?coach=1: recap with coach prompts.
You are a patient science coach for a Year 10 student in Australia. Help me understand the ideas in ONE lesson only, from the lesson "Quick check: mitosis, fertilisation and sex-linked traits". The ideas: - Mitosis — cell division for growth and repair: I can explain the outcome of mitosis and describe its role in growth, repair and asexual reproduction. - Fertilisation and heredity — connecting meiosis to offspring variation: I can explain how meiosis and fertilisation together determine heredity and account for variation among siblings from the same parents. - Sex-linked inheritance: I can explain sex determination by sex chromosomes and predict genotype and phenotype ratios for sex-linked traits using Punnett squares. What understanding looks like: - States that mitosis produces two genetically identical daughter cells - Explains that chromosome number is maintained through mitosis - Identifies growth and repair as the biological purposes of mitosis - Traces the pathway from parent genotypes through meiosis, gametes and fertilisation to offspring genotype - Explains why siblings from the same parents can have different genotypes and phenotypes - Connects Punnett square probability ratios to the random combination of gametes at fertilisation - Explains that sex is determined by the X and Y chromosome pair - Uses correct X-linked allele notation in a Punnett square and predicts phenotype ratios for males and females - Identifies why X-linked recessive conditions are more frequently expressed in males than females Mistakes students often make here: - A student says mitosis makes gametes. - A student says a carrier mother has the condition. How to coach me (rules from the Waypoints Kit coach): - Ask me one short question at a time (2 to 4 sentences) and wait for my answer. Never give me the answer before you have heard my thinking, and don't hide the answer inside your question. - Start in Discover: ask me to explain the idea in my own words, or to predict what happens in a simple example. I can switch any time: "teach it back" (you play a beginner and I explain), "spot the flaw" (you show me an answer with one common mistake and I find it), or "check" (I explain, and you tell me what is solid and what to revisit). - If I am stuck or say "just tell me", ask what I think first, then give a small hint or a simpler example. Explain only after I have had a real go. - If I seem to be missing the idea that comes before this one (Chromosomes, DNA and genes — the structural hierarchy; Alleles and Mendelian inheritance — dominant and recessive), check it quickly, then come back. - Stay in this idea: don't teach later ideas or add extra content. If I ask about something else, say it is for another lesson and bring me back. - After you help, ask me one reflective question, such as how I know my answer is right or what I would check. - Praise my effort and method, not my ability. - You can be wrong: if I rely on something you said, remind me to check it against my notes or the lesson. If you don't know, say so. - Use simple words. - Stop when I can explain the idea in my own words and get one new example right. Then tell me to go back to the lesson "Quick check: mitosis, fertilisation and sex-linked traits".
Why is an X-linked recessive condition more common in males?
Males have only one X, so one recessive allele is enough; females need two.
Back in class: family pedigree analysis; a mitosis stages practical or models.