Where Does Photosynthesis Take Place?
Photosynthesis is not a single point of activity but a beautifully organised division of space and duty inside the plant cell. This quiz explores the chloroplast — the organelle where the work happens — and how its internal geography separates the capture of light from the building of sugar.
You will be tested on:
- The green leaf and other green parts of the plant where photosynthesis occurs
- Mesophyll cells and the positioning of chloroplasts for optimum light
- The membranous system of grana and stroma lamellae, and the matrix stroma
- The clear division of labour: ATP and NADPH versus sugar and starch
- Why the term dark reactions must be read with care
Read each question carefully — the distractors are designed to test precise understanding, not guesswork. Good luck!
Q1. Photosynthesis occurs in the green leaves of plants and also in which other parts of the plant body?
The lesson states that photosynthesis takes place in the green leaves but also in other green parts of the plant body, since any tissue carrying chlorophyll and receiving light can contribute.
Q2. Within the leaf, which cells contain a large number of chloroplasts and form the photosynthetic tissue?
The mesophyll cells in the leaves have a large number of chloroplasts and form the photosynthetic tissue in the interior of the leaf.
Q3. Chloroplasts in mesophyll cells usually align themselves along the cell walls so that they receive:
Chloroplasts align along the walls of mesophyll cells such that they get the optimum quantity of the incident light.
Q4. The membranous system within the chloroplast consists of grana, stroma lamellae, and which matrix?
Within the chloroplast there is a membranous system consisting of grana, the stroma lamellae, and the matrix stroma.
Q5. Which part of the chloroplast is responsible for trapping light energy and synthesising ATP and NADPH?
The membrane system is responsible for trapping the light energy and also for the synthesis of ATP and NADPH.
Q6. In which part of the chloroplast do enzymatic reactions synthesise sugar?
In the stroma, enzymatic reactions synthesise sugar, which in turn forms starch.
Q7. The sugar synthesised by enzymatic reactions in the stroma in turn forms:
The lesson states that sugar synthesised in the stroma in turn forms starch.
Q8. The light reactions are also known as:
The light reactions, since they are directly light driven, are called light reactions or photochemical reactions.
Q9. The dark reactions are also known by which alternative name?
By convention the latter set of reactions are called dark reactions or carbon reactions.
Q10. The dark reactions are dependent on which products of the light reactions?
The dark reactions are not directly light driven but are dependent on the products of the light reactions, namely ATP and NADPH.
Q11. Which statement about the dark reactions is correct according to the lesson?
The lesson warns that the term dark reactions should not be construed to mean that they occur in darkness or that they are not light-dependent.
Q12. The clear division of labour within the chloroplast means that:
There is a clear division of labour: the membrane system traps light energy and synthesises ATP and NADPH, while enzymatic reactions in the stroma synthesise sugar.
Q13. Why are the light reactions described as photochemical reactions?
The light reactions are called photochemical reactions because they are directly light driven.
Q14. Which of the following is NOT part of the membranous system of the chloroplast as described in the lesson?
The membranous system consists of grana and stroma lamellae; the stroma is the matrix, not part of the membranous system.
Q15. The dark reactions are said to be light-dependent because:
Although not directly light driven, the dark reactions depend on the products of the light reactions (ATP and NADPH), and hence are light-dependent.