Ways of feeding, and photosynthesis
Every mouthful of breadfruit you eat began as light energy caught by a leaf. That is photosynthesis, and it feeds almost every living thing on Earth, including you.
By the end of this page you can
- Tell autotrophic, heterotrophic and saprophytic nutrition apart
- Say what goes into photosynthesis and what comes out, with the equation
- Put the steps of photosynthesis in order
- Use the key terms correctly
- Answer exam questions on photosynthesis
Goals tick themselves off as you try the activities below.
Photo: Forest and Kim Starr, CC BY 3.0, via Wikimedia Commons. Cropped.
A breadfruit tree. Its leaves make sugar by photosynthesis, and the tree stores it as starch in the fruit.
How often it shows up in past papers
Paper 1 counts come from our past-paper bank of CSEC Biology Paper 1s. Paper 2 is not included yet.
Make it, eat it, or absorb it
Every organism needs food for energy and growth. There are three ways to get it. Tap each card.
Photosynthesis in one equation
Carbon dioxide + water → glucose + oxygen, using light and chlorophyll. Balanced: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
In and out of a leaf
Tap a part on the list to see its role in photosynthesis.
It all happens in the chloroplasts: carbon dioxide goes in, oxygen comes out.
Four steps inside the chloroplast
Put the steps of photosynthesis in order. Drag or tap each card into its slot.
What happens first?
Seven terms to know cold
Say what each term means before you flip the card. The first three are a set: learn them together.
Six quick questions, then a real one
Pick an answer to see why it’s right or wrong.
The equation X + 6H₂O → C₆H₁₂O₆ + Y shows photosynthesis. What are X and Y?
A leaf with green and white patches is left in sunlight, then tested with iodine. Only the green parts turn blue-black. What does this show is needed for photosynthesis?
Bubbles collected from a pondweed in bright light would be mostly
Which substance is NOT needed for photosynthesis?
Which organism is a saprophyte?
Which pair can make carbohydrates from simple inorganic substances?
exam style · 3 marks
Describe what happens to water and to carbon dioxide during photosynthesis, and state where in the cell photosynthesis takes place.
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Practice questions are written by My V.I.P. Academy. They are not official CXC papers.