--- title: "Organ systems" subtitle: "Year 8 Biology · From cells to organs · Lesson 8" --- # Organ systems **Name:** {{field-24}} **Date:** {{field-15}} **Class:** {{field-15}} > **Key question:** Your heart can't keep you alive on its own, and neither can your lungs. Why do organs only make sense as a team? :::teacher-note **In one sentence:** Students name the organs of one animal system and one plant system, explain how they coordinate to do a survival job, and compare the two as solutions to a shared problem (AC9S8U02, node 4). **Students should be able to say:** I can name organs of an animal and a plant system and say what each does. I can say how the organs work as a system. I can compare the two systems. **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. ::: ## Engage :::keep-together **In the circulatory system, the heart pumps blood through blood vessels to all parts of the body. If the blood vessels to one leg are blocked, what is most likely?** ☐ Only the heart is affected ☐ That leg doesn't get enough oxygen and nutrients, so the system as a whole can no longer do its job there ☐ Nothing: the heart still works ☐ The other leg gets more blood so the body is fine My prediction, and why: {{lines-3}} ::: :::teacher-note **What happens:** The leg is starved of oxygen and nutrients. A system only works when every organ in it does its part: pump, vessels and blood together. ::: ## Explain: systems at work :::keep-together ### Circulatory system **Match each part of the circulatory system to its job.** A. Carry blood back to the heart B. Pumps blood around the body C. Carries oxygen, nutrients and waste D. Carry blood away from the heart at high pressure E. Thin walls let oxygen and nutrients pass into cells {{columns 60% 40%}} {{rows 1}} | Part | Letter | |---|---| | `Heart` | | | `Arteries` | | | `Veins` | | | `Capillaries` | | | `Blood` | | ::: :::teacher-note **Answer:** Heart → B. Pumps blood around the body; Arteries → D. Carry blood away from the heart at high pressure; Veins → A. Carry blood back to the heart; Capillaries → E. Thin walls let oxygen and nutrients pass into cells; Blood → C. Carries oxygen, nutrients and waste ::: :::keep-together ### Plant system **Match each part of a plant's vascular system to its job.** A. Take in water and minerals from the soil B. Carries sugars from the leaves to where they are needed C. Make sugars by photosynthesis and lose water vapour D. Carries water and minerals up the plant {{columns 60% 40%}} {{rows 1}} | Part | Letter | |---|---| | `Roots` | | | `Xylem` | | | `Phloem` | | | `Leaves` | | ::: :::teacher-note **Answer:** Roots → A. Take in water and minerals from the soil; Xylem → D. Carries water and minerals up the plant; Phloem → B. Carries sugars from the leaves to where they are needed; Leaves → C. Make sugars by photosynthesis and lose water vapour ::: :::keep-together ### The shared problem **What survival problem do the circulatory system and a plant's vascular system both solve?** ☐ Making sound ☐ Moving materials (nutrients, water, gases) to every cell that needs them ☐ Getting rid of heat ::: :::teacher-note **Answer:** Moving materials (nutrients, water, gases) to every cell that needs them Cells deep inside a body can't get what they need by themselves, so both kinds of organism use a transport system. ::: :::keep-together ### The difference **How is the plant's system different from the animal's?** ☐ A plant's system moves only water; an animal's moves food as well ☐ A plant has a heart in its roots ☐ A plant has no pump: water is pulled up by evaporation from the leaves, and the tubes are fixed in place ::: :::teacher-note **Answer:** A plant has no pump: water is pulled up by evaporation from the leaves, and the tubes are fixed in place Animals actively pump a liquid round a loop; plants move water upward in tubes as it evaporates from the leaves. Different bodies, same problem. ::: :::typical ## Elaborate: the digestive system :::keep-together **In digestion, food goes mouth, then stomach, then small intestine. If the small intestine fails to absorb nutrients, what is the effect on the system?** ☐ The mouth does the absorbing instead ☐ No effect because the stomach still works ☐ The system fails at its job: food is broken down but the nutrients never get into the blood ::: :::teacher-note **Answer:** The system fails at its job: food is broken down but the nutrients never get into the blood Each organ does a step in the job. If any step fails, the system fails to do its whole job. ::: ::: :::wider ## Elaborate: a machine for an organ :::keep-together **A dialysis machine cleans the blood of someone whose kidneys no longer work. What does it do that the kidney does?** ☐ Filters waste out of the blood, while keeping useful things in ☐ Pumps the blood round the body ☐ Makes new blood cells ::: :::teacher-note **Answer:** Filters waste out of the blood, while keeping useful things in To replace an organ you must copy what it does. Here the machine filters waste out of the blood, as the kidney does. ::: ::: ## Evaluate: look back Write one sentence: "At first I thought… Now I think… because…" **Revision summary** - An **organ system** is a group of organs working together to do a job the whole organism needs. - Animal example: **circulatory** (heart, vessels, blood). Plant example: **vascular** (roots, xylem, phloem, leaves). - If any organ in a system fails, the system can't do its job. - Both systems solve the same problem: **moving materials to every cell**. ## Exit ticket :::keep-together **Say in a sentence how a plant's vascular system and an animal's circulatory system are alike, and one way they differ.** {{lines-3}} ::: :::teacher-note **Answer:** Alike: both move materials to every cell. Different: the animal pumps blood with a heart, while the plant has no pump and water is pulled up the xylem as it evaporates from the leaves. :::