Do Plants Respire?
Class 7 Science · Chapter 10: Life Processes in Plants · NCERT Curiosity section 10.4
Learn
Meher puts soaked moong seeds on wet cotton in a closed flask for a day in the dark, then lets the air from the flask bubble into lime water. It turns milky; plain air does not. The germinating seeds gave out carbon dioxide: they respire.
Like animals, plants break down glucose with oxygen to release energy for growth: glucose + oxygen → carbon dioxide + water + energy. Every living part respires, green or not: roots, stems, flowers and seeds, day and night. Photosynthesis happens only in green parts and only in light. Both use the stomata to exchange gases.
glucose + oxygen → carbon dioxide + water + energy
Explore: photosynthesis or respiration?
- Sort each feature.
Remember
- Plants respire: glucose + oxygen → carbon dioxide + water + energy, in every living part, day and night.
- Photosynthesis makes food in green parts in light; respiration uses it for energy.
Quick check
Which parts of a plant respire?
- all living parts, green or not
- only the leaves
- only the flowers
- none
Answer
all living parts, green or not. Every living cell needs energy.
Think about it
Why do stored potatoes slowly shrink and lose weight?
One answer
They keep respiring, using up stored food and giving off carbon dioxide and water, so they lose mass over time.
Practice
Practise with fresh questions at three levels (easy, medium, hard), some answered hands-on, with hints and worked answers. Get 4 of your last 5 right to finish the topic.