--- title: "Quick check: reproductive organs and strategies" subtitle: "Year 9 Biology · Reproduction · Lesson 9" --- # Quick check: reproductive organs and strategies **Name:** {{field-24}} **Date:** {{field-15}} **Class:** {{field-15}} > **Key question:** A strawberry plant sends out runners; a bacterium splits in two. When is cloning a good strategy, and when is it risky? :::teacher-note **In one sentence:** A self-test on reproductive organs and on asexual and sexual strategies and their trade-offs (AC9S9U02, nodes 2, 4 and 5, taught in class; node 4 a hinge). **Students should be able to say:** I can name reproductive structures and what they do. I can describe two kinds of asexual reproduction. I can compare sexual and asexual reproduction and say when each helps. **Width:** the unmarked parts are the floor every student does (Engage, Explore, Explain, Evaluate). Typical and Wider sections add contexts, not difficulty. Students work in the online tutorial alongside this sheet. ::: ## Reproductive organs :::keep-together ### What does each do? **What is the main job of this structure?** Groups: Makes gametes, Transfers or receives gametes, Where the embryo develops - Testis: {{field-15}} - Ovary: {{field-15}} - Anther (in a flower): {{field-15}} - Sperm duct: {{field-15}} - Stigma: {{field-15}} - Uterus: {{field-15}} ::: :::teacher-note **Answer:** Testis → Makes gametes; Ovary → Makes gametes; Anther (in a flower) → Makes gametes; Sperm duct → Transfers or receives gametes; Stigma → Transfers or receives gametes; Uterus → Where the embryo develops ::: :::keep-together ### Pollination **What is pollination?** ☐ The growing of a seed into a plant ☐ The joining of a male and a female gamete ☐ The release of eggs from an ovary ☐ The transfer of pollen from an anther to a stigma ::: :::teacher-note **Answer:** The transfer of pollen from an anther to a stigma Pollination is transfer. Fertilisation comes later, when the pollen's male gamete reaches the ovule and joins the female gamete. ::: :::keep-together ### Working together **How do the male and female reproductive structures work together?** ☐ The male structures make the embryo and the female structures only feed it ☐ Either set can make offspring on its own; the other is a backup ☐ The gametes join inside the testis or the anther ☐ Each makes gametes, and the structures carry them to meet so fertilisation can happen ::: :::teacher-note **Answer:** Each makes gametes, and the structures carry them to meet so fertilisation can happen Gametes are made in separate structures and brought together, which is what allows fertilisation. ::: :::keep-together ### Stamen and carpel **Match each flower part to its job.** A. Receives pollen and holds the ovules, where fertilisation happens B. Attract pollinators C. Makes and holds pollen, which carries the male gametes {{columns 60% 40%}} {{rows 1}} | Part | Letter | |---|---| | `Stamen (anther and filament)` | | | `Carpel (stigma, style and ovary)` | | | `Petals` | | ::: :::teacher-note **Answer:** Stamen (anther and filament) → C. Makes and holds pollen, which carries the male gametes; Carpel (stigma, style and ovary) → A. Receives pollen and holds the ovules, where fertilisation happens; Petals → B. Attract pollinators ::: ## Asexual reproduction :::keep-together ### Asexual or sexual? **Is it asexual or sexual reproduction?** Groups: Asexual, Sexual - A strawberry plant growing new plants on runners: {{field-15}} - A hydra growing a bud that breaks away: {{field-15}} - A bacterium splitting in two: {{field-15}} - A flower pollinated and making seeds: {{field-15}} - An egg fertilised by a sperm: {{field-15}} ::: :::teacher-note **Answer:** A strawberry plant growing new plants on runners → Asexual; A hydra growing a bud that breaks away → Asexual; A bacterium splitting in two → Asexual; A flower pollinated and making seeds → Sexual; An egg fertilised by a sperm → Sexual ::: :::keep-together ### When it helps **When is asexual reproduction an advantage?** ☐ When the species needs variety ☐ When the environment changes suddenly ☐ In a stable environment or when spreading quickly, because one parent can make many offspring fast ☐ Never ::: :::teacher-note **Answer:** In a stable environment or when spreading quickly, because one parent can make many offspring fast There is no need to find a mate, so a successful organism can quickly fill a suitable place with copies of itself. ::: :::keep-together ### The limit **What is the main limit of asexual reproduction?** ☐ Offspring are genetically identical, so one disease or change can harm them all ☐ It can only happen in plants ☐ It is too slow ☐ It needs two parents ::: :::teacher-note **Answer:** Offspring are genetically identical, so one disease or change can harm them all No variation means no individuals with different traits that might survive a new threat. ::: ## Comparing strategies :::keep-together ### Sexual or asexual? **Which strategy does this describe?** Groups: Sexual, Asexual - Offspring differ from each other and their parents: {{field-15}} - Offspring are clones of the parent: {{field-15}} - Many offspring can be made quickly by one parent: {{field-15}} - Needs gametes from two parents: {{field-15}} - Gives some chance of survival if the environment changes: {{field-15}} - Needs energy and time to find a mate and make gametes: {{field-15}} - Needs only one parent, so less energy is spent per offspring: {{field-15}} ::: :::teacher-note **Answer:** Offspring differ from each other and their parents → Sexual; Offspring are clones of the parent → Asexual; Many offspring can be made quickly by one parent → Asexual; Needs gametes from two parents → Sexual; Gives some chance of survival if the environment changes → Sexual; Needs energy and time to find a mate and make gametes → Sexual; Needs only one parent, so less energy is spent per offspring → Asexual ::: :::keep-together ### A new disease **A new disease spreads through a population. Which population is more likely to have survivors?** ☐ One that reproduces sexually, because its variation may include resistant individuals ☐ One that reproduces asexually, because the clones are identical ☐ Neither can have survivors ☐ Both are equally likely ::: :::teacher-note **Answer:** One that reproduces sexually, because its variation may include resistant individuals Variation gives a chance that some individuals can resist. In a population of clones, if one cannot resist the disease, none can. ::: :::keep-together ### Using both **Aphids reproduce asexually in summer and sexually in autumn. Why might it help to use both?** ☐ Asexual is fast when conditions are good; sexual makes variation for harder times ☐ Sexual is faster in summer ☐ Asexual makes more variation ☐ It makes no difference ::: :::teacher-note **Answer:** Asexual is fast when conditions are good; sexual makes variation for harder times Each strategy suits different conditions, so species that use both can do well in changing environments. ::: ## Exit ticket :::keep-together **Give one advantage and one disadvantage of asexual reproduction.** {{lines-3}} ::: :::teacher-note **Answer:** Advantage: fast with one parent. Disadvantage: no variation, so one change or disease can harm all. :::