Quizmo

Quiz on Photosynthesis

20 questions · June 27, 2026

Below is the full Quizmo quiz devoted to the theme "Photosynthesis": each question, its four options, the correct answer highlighted and, where available, its source. A chance to brush up on your general knowledge and then test what you know.

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Question 1

Easy

Which gas do plants release during photosynthesis?

Source: Nearly all the oxygen you breathe was first exhaled by a plant or an alga.

Question 2

Easy

Which plant organ carries out most photosynthesis?

Source: Leaves are basically flat solar panels built to soak up as much sunlight as possible.

Question 3

Easy

What is the main energy source powering photosynthesis?

Source: It runs on light, not heat, so even a freezing sunny day keeps it going.

Question 4

Easy

Besides plants, which organisms also perform photosynthesis?

Source: Ocean algae, not forests, generate more than half of all the oxygen on Earth.

Question 5

Easy

Which pigment captures light energy inside a leaf?

Source: Chlorophyll reflects green light, which is exactly why most plants look green.

Question 6

Easy

Besides sunlight and air, what raw material must a plant absorb?

Source: Roots pull up the water that gets split apart to release oxygen and power sugar-making.

Question 7

Easy

Photosynthesis converts light energy into what kind of energy?

Source: Sunlight gets locked into sugar bonds, stored chemical energy you later eat.

Question 8

Easy

In which cell structure does photosynthesis take place?

Source: Chloroplasts are tiny solar factories that carry their own DNA, once free-living bacteria.

Question 9

Easy

Which sugar does photosynthesis mainly produce?

Source: Plants make glucose first, then repackage it into starch, cellulose, or sweeter sugars.

Question 10

Easy

Which colour of light do plants use the least?

Source: Plants bounce green light back instead of absorbing it, and that reflection is what you see.

Question 11

Medium

Which leaf pores open and close to control gas exchange?

Source: Each pore is flanked by guard cells that swell to open it and droop to seal it shut.

Question 12

Medium

What is the name of the cycle that fixes carbon into sugar?

Source: It was mapped using radioactive carbon, earning Melvin Calvin a Nobel Prize.

Question 13

Medium

The light-dependent reactions take place in which part of the chloroplast?

Source: Light reactions run on stacked thylakoid discs bundled together into grana.

Question 14

Medium

Which molecule stores the energy captured in the light reactions?

Source: The light reactions charge up ATP and NADPH that then fuel the sugar-building cycle.

Question 15

Medium

Which pathway lets corn and sugarcane thrive in hot, bright climates?

Source: These plants concentrate carbon dioxide internally so they barely lose water in the heat.

Question 16

Medium

Splitting water in photosynthesis releases oxygen and what else?

Source: Plants tear water apart mainly to harvest the electrons that drive the whole process.

Question 17

Medium

Roughly what share of sunlight do plants turn into chemical energy?

Source: Leaves are surprisingly inefficient, and modern solar panels easily out-capture them.

Question 18

Hard

Which pigments give carrots and autumn leaves their orange and yellow?

Source: They hide in leaves all summer and only show up once chlorophyll fades in fall.

Question 19

Hard

Which enzyme grabs carbon dioxide during the Calvin cycle?

Source: It is the most abundant protein on Earth, yet notoriously sluggish at its job.

Question 20

Hard

What do scientists call photosynthesis that produces no oxygen?

Source: Some bacteria run on sulfur instead of water, so they release no oxygen at all.

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