Biology

Photosynthesis in Plants

1,508 Questions

Photosynthesis is the biological process by which plants convert light energy into chemical energy. This page contains practice questions covering essential topics like chlorophyll, light reactions, and the pathways specific to plants. This material is crucial for medical entrance exams and academic assessments.

Chlorophyll and pigmentsLight reactionsCalvin cycleCAM plantsElectron transportPhotosynthesis factors

Photosynthesis in Plants Questions

Multiple choice

The light harvesting complex in plants and algae is

  1. a protein

  2. the thylakoid

  3. the chlorophyll

  4. ATP

  5. NADPH
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is correct. Plants absorb light primarily using the pigment chlorophyll, the pigment is embedded in plants and algae in special antenna-proteins. In such proteins all the pigments are ordered to work together. Such a protein is also called a light harvesting complex.

Multiple choice

Which of the following schemes of transfer of electrons shows 'Z' scheme?

  1. PS II______PS I _NADP+H+_________NADP+

  2. PS I______PS II _NADP+H+_________NADP+

  3. PS I______PS II _NADP+_________NADP+H+

  4. PS II______PS I _NADP+_________NADP+H+

  5. NADP+_______NADP+H+PS II______PS I
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yes, it is correct. This whole scheme of transfer of electrons, starting from the PS II, uphill to the accepter, down the electron transport chain to PS I, excitation of electrons, transfer to another accepter, and finally down hill to NADP+ causing it to be reduced to NADPH+H+ is called the Z scheme.

Multiple choice

Directions: Fill in all the four blanks -1, 2, 3, and 4.

In PS I, the reaction centre chlorophyll has an absorption peak at __1_ hence, is called __2, while in PS II, it has absorption maxima at __3, and is called ___4.

  1. 1 - 700nm, 2 - P700, 3 - 680nm, 4 - P680

  2. 1 - 1700nm, 2 - P1700, 3 - 1680nm, 4 - P1680

  3. 1 - 700, 2 - P700nm, 3 - 680, 4 - P680nm

  4. 1 - P700, 2 - 700nm, 3 - P680, 4 - 680nm

  5. 1 - 70nm, 2 - P70, 3 - 68nm, 4 - P68
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The LHC is made up of hundreds of pigment molecules bound to proteins. The single chlorophyll molecule forms the reaction centre. The reaction centre is different in both the photosystems. In PS I the reaction centre chlorophyll a has an absorption peak at 700 nm, hence is called P700, while in PS II it has absorption maxima at 680 nm, and is called P680.

Multiple choice

Which of the following are the three stages of the Calvin cycle?

  1. Carboxylation, photorespiration and regeneration

  2. Carboxylation, reduction and regeneration

  3. Photosynthesis, reduction and oxidation

  4. Reduction, photorespiration and regeneration

  5. Oxidation, reduction and regeneration
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Yes, it is correct. Calvin and his co-workers worked out the whole pathway and showed that the pathway operated in a cyclic manner; the RuBP (Ribulose bisphosphate) was regenerated. The Calvin cycle can be described under three stages: carboxylation, reduction and regeneration.

Multiple choice

Light reactions or the ‘Photochemical’ phase includes which of the following steps? (a) Light dispersion (b) Splitting of water (c) Release of oxygen (d) Formation of ATP and NADP (e) Assimilation of chlorophyll

  1. a, b, c and d

  2. b and c

  3. b, c and d

  4. c, d and e

  5. a and e
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is correct. Light reactions or the ‘Photochemical’ phase includes light absorption, water splitting, oxygen release, and the formation of high-energy chemical intermediates, ATP and NADPH.

Multiple choice

What is the colour of leaves in which chlorophyll is present?

  1. Green

  2. Red and purple

  3. Orange and yellow

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yes, it is the correct. The coloured leaves have chlorophyll too. Here, the green colour is not visible to our eyes, as it is present in very less amount. Hence, we can say that all the leaves possess chlorophyll.