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 chemistry air and water pollution ways to prevent air pollution ways to reduce air pollution reducing air pollution

Green plants during day time absorb :

  1. $O _{2}$
  2. $CO _{2}$
  3. $CO$
  4. $N _{2}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A plant, like an animal, needs energy. Plants have a process called photosynthesis to transform light energy into chemical energy (glucose sugar). Plants produce oxygen during photosynthesis, the oxygen is derived from the water it intakes and not from the carbon dioxide. 


The hydrogen from water, the carbon from carbon dioxide, and the oxygen from carbon dioxide go into the glucose compound  (C$ _6$H$ _{12}$O$ _6$)

Hence, the correct option is $\text{B}$

Multiple choice biology photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

How many of the given structures are associated with the thylakoid membrane?
PS II, RuBisCO, LHC, PEPcase, $F _0$ of ATP synthase, cytochromes b & f.

  1. $2$
  2. $3$
  3. $4$
  4. $5$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The structures associated with the thylakoid membrane are PS II, LHC, F0 of ATP synthase, and cytochromes b & f. RuBisCO is found in the stroma, and PEPcase is found in the cytoplasm of mesophyll cells, making a total of 4 structures.

Multiple choice biology photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

Read the following statements.
i) Chloroplasts get aligned with their flat surface parallel to the cell walls to receive optimum light intensity.
ii) Water is the only electron donor in all photosynthetic organisms.
iii) ATP and NADPH are utilised in Carboxylation stage of Calvin cycle.
iv) Bundle sheath cells are characterized by having a large number of chloroplasts and impervious walls.
v) Law of limiting factors was proposed by Blackmann.
Which of the given statements are CORRECT?

  1. (i), (iii) and (iv)

  2. (i), (ii) and (iii)

  3. (iii), (iv) and (v)

  4. (v) only
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice biology nutrition - food supplying system site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

Consider the following processes.
a. $O _2$ evolution
b. $CO _2$ fixation
c. NADPH formation
d. Chlorophyll biosynthesis.
Which of these do not occur in thylakoids?

  1. $1$ and $2$
  2. $2$ and $3$
  3. $3$ and $4$
  4. $2$ and $4$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oxygen evolution, NADPH formation, and light reactions occur in the thylakoids. CO2 fixation (Calvin cycle) occurs in the stroma, and chlorophyll biosynthesis involves multiple cellular compartments including plastids and cytoplasm, meaning 2 and 4 do not exclusively occur in thylakoids.

Multiple choice biology nutrition - food supplying system site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

If $^{14}CO _2$ is added to a suspension of photosynthesizing chloroplasts, which of the following will be the first compound to be radioactive?

  1. ATP

  2. NADPH

  3. NADH
  4. $3$-phosphor glycerate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the Calvin cycle, CO2 is first fixed by RuBisCO to form 3-phosphoglycerate, which is the first stable radioactive compound.

Multiple choice biology nutrition - food supplying system site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

With reference to photosynthesis in chloroplasts, consider the following statements.
a. The reactions that break down water and produce oxygen are located on the lumen side of the thylakoid membrane, in granum areas.
b. The molecules of ferredoxin-NADP re-educate that generate NADPH are located on the side of the membrane facing stroma.
Which of the statements given is/are correct?

  1. $1$ only
  2. $2$ only
  3. Both $1$ and $2$
  4. Neither $1$ nor $2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice biology nutrition - food supplying system site of photosynthesis chloroplast and pigments of photosynthesis pigments

Which of the following pairs are correctly matched? Principal wavelength Physiological of light event.
a. $700$nm- Photo system I
b. $650$nm- Photo system II
c. $690$nm- Photo system III
d. $620$nm- Phycocyanin
Select the correct answer using the codes given.

  1. $1, 2$ and $4$
  2. $1, 3$ and $4$
  3. $2$ and $4$
  4. $1$ and $3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

PS I absorbs at 700nm, PS II at 680nm (650nm is often associated with accessory pigments/PS II complex), and Phycocyanin absorbs around 620nm. PS III does not exist.

Multiple choice biology nutrition - food supplying system site of photosynthesis chloroplast and pigments of photosynthesis pigments

Following table summarises the differences between light reaction and dark reaction. 

Light reaction     Dark reaction      
i These arealso called as biosynthetic phase These are also calledas photochemicalphase
ii These reactionoccur over thylakoids. These reaction occur in stroma of chloroplasts.
iii These produce assimilatory power i.e.$NADPH _{2}$and ATP  These consume $NADPH _{2}$ and ATP.
iv  These are directiondependent uponlight. These depend upon the products synthesisedduring light reaction

Which of the above pairs of difference is/are incorrect?

  1. (i) and (iv)

  2. (iii) and (iv)

  3. (ii) only

  4. (i) only
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The light reaction is also called as photochemical phase whereas dark reaction is called as biosynthetic phase.

So the correct option is D.

Multiple choice biology photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

Why does the total amount of $CO _2$ in the atmosphere remains constant even though respiration liberates $CO _2$?

  1. $CO _2$ acts as a buffer
  2. $CO _2$ is converted to carbohydrates in photosynthesis
  3. $CO _2$ forms carbonic acid
  4. $CO _2$ undergoes cleavage during photosynthesis.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Most organisms release or exhale $CO _2$ during respiration. This $CO _2$  present in the environment is utilized by plants in the process of photosynthesis with the final product being a carbohydrate. This is how the amount of $CO _2$  in the atmosphere is kept under check.
So, the correct answer is '$CO _2$  is converted to carbohydrates in photosynthesis'.
Multiple choice botany the leaf mechanism of absorption mineral absorption significance of transpiration

Grafted flower is contained in saline water because

  1. Suitable nutrient available to flower

  2. Flower remains fresh in long duration due to less transpiration

  3. The flower is protected by microbes

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water moves from high water potential to less water potential. Also it is assumed that transpiration loss of water equals water absorption. In saline water there will be less of transpiration loss as absorption will be less. Consequently there are less chances of wilting.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

Select correct statement(s).

  1. $Mg^{2+}$ ions are necessary for the activation of phosphate transfer enzymes.

  2. Mg is present in chlorophyll of green plants.

  3. Mg is present in chlorophyll used in photosynthesis in green plants.

  4. All the above are correct statements
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mg2+ is indeed a cofactor for phosphate transfer enzymes (like kinases) and is the central atom in chlorophyll, which is used in photosynthesis.