Good Learning Co.
SavannahYear 8
← Science
ScienceLife processes26 min★★ difficulty

Photosynthesis and stomata

Photosynthesis is the process that ultimately feeds almost every living thing on Earth, and it depends on tiny pores that let gases in and out of leaves.

Part of your national curriculum
  • Biology: material cycles and energy: Understand the role of leaf stomata in gas exchange in plants and the dependence of almost all life on Earth on the ability of photosynthetic organisms to use sunlight

Lesson overview

What you'll learn in this lesson

Understand the role of leaf stomata in gas exchange in plants and the dependence of almost all life on Earth on the ability of photosynthetic organisms to use sunlight

Key learning points

  • • Photosynthesis
  • • Stomata and gas exchange
  • • The base of almost all food chains

This lesson at a glance

  • 26 minutes
  • 14 parts to scroll through
  • 3 quick checks
  • Marked quiz at the end
  • Gentle pace: short sittings with pauses

Words to know

stomataexchangeplantsdependencealmost

Scroll down — the lesson carries on below

Part 1 of 14 · Discover7%
1

Watch & discover

Part 1 of 14

Watch first

Photosynthesis and stomata

An English teaching video on this topic from iNewittAll. Watch it, then scroll down for the lesson.

In a nutshell

Understand the role of leaf stomata in gas exchange in plants and the dependence of almost all life on Earth on the ability of photosynthetic organisms to use sunlight

2

Learning cycle

Part 2 of 14

Learning cycle 1 of 2

Part 1 · Photosynthesis

A short piece of teaching, then a check to make sure it has landed.

3

Explore the idea

Part 3 of 14

Learn

Photosynthesis

Photosynthesis is: carbon dioxide + water + (light energy) → glucose + oxygen. It happens in chloroplasts, which contain chlorophyll to absorb light energy. The glucose produced is used for respiration, growth, and storage as starch.

4

Explore the idea

Part 4 of 14

Learn

Stomata and gas exchange

Stomata are tiny pores, mostly on the underside of leaves, surrounded by guard cells that open and close them. Carbon dioxide diffuses in and oxygen diffuses out through open stomata; water vapour also escapes, a process called transpiration.

5

Quick check

Part 5 of 14

Quick check

What gas do stomata mainly let into the leaf for photosynthesis?

6

Reset break

Part 6 of 14

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
7

Quick check

Part 7 of 14

Quick check

What controls the opening and closing of stomata?

8

Learning cycle

Part 8 of 14

Learning cycle 2 of 2

Part 2 · The base of almost all food chains

A short piece of teaching, then a check to make sure it has landed.

9

Explore the idea

Part 9 of 14

Learn

The base of almost all food chains

Photosynthetic organisms — plants, algae and some bacteria — are producers. They are the ultimate energy source for nearly every food chain, since consumers get their energy by eating producers or other consumers that ate producers.

10

Quick check

Part 10 of 14

Quick check

Why are photosynthetic organisms essential to almost all life on Earth?

11

Challenge round

Part 11 of 14

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

12

Challenge round

Part 12 of 14

Game · Fill the gaps

Finish the sentences

Choose the word that belongs in each gap.

____ are tiny pores, mostly on the underside of leaves, surrounded by guard cells that open and close them.

Photosynthetic organisms — ____, algae and some bacteria — are producers.

13

Mastery quiz

Part 13 of 14

Marked quiz

End of lesson quiz: Photosynthesis and stomata

3 questions, marked with the reasoning shown. No timer.

  1. 1. What gas do stomata mainly let into the leaf for photosynthesis?

  2. 2. What controls the opening and closing of stomata?

  3. 3. Why are photosynthetic organisms essential to almost all life on Earth?

14

Lesson round-up

Part 14 of 14

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

0

Best run

0 in a row

Luna: 0 out of 3 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Why the school greenhouse failed

A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.

The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.

The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.

Written for Good Learning Co.

Reading questions

  1. Name the variable the club changed the second time, and one variable they kept the same.
  2. Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
  3. Write a conclusion for the club's report, saying how far the evidence supports it.

  • Method and results

    Writing

    Write the aim, what you changed, what you measured and what you kept the same, then record your results in a table.

    1 page + results table

  • Conclusion

    Writing

    Explain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.

    6–8 sentences

  • Labelled diagram

    Diagram

    Draw the apparatus or the process in pencil, label it fully, and photograph it.

    1 labelled diagram

  • Reading and notes

    Reading

    Read the lesson text again and write the key ideas in your own words.

    Half a page of notes

Saved as you type.

Part 1 of 14 · Watch & discover

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    Understand the role of leaf stomata in gas exchange in plants and the dependence of almost all life on Earth on the ability of photosynthetic organisms to use sunlight

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