Biology

Photosynthesis in Plants

1,492 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 biology cell structure and micro-organisms plant and animal cell cell structure organisation of the organism

Plant cell can do___________

  1. Breathing and respiration

  2. Respiration and photosynthesis

  3. Breathing and photosynthesis

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The plant cell can do respiration and photosynthesis. The plants get energy through the process of respiration in which glucose food breaks down in the presence of oxygen to form carbon dioxide and water with the release of energy. In plants, photosynthesis takes place in the cell organelle called chloroplast. A plant cell cannot breathe because in a plant body lungs are absent.
So the correct answer is 'Respiration and photosynthesis'.
Multiple choice zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

The biological process by which carbon is returned to its reservoir is

  1. photosynthesis

  2. denitrification

  3. carbon fixation

  4. cellular respiration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Photosynthesis is the process in which plants prepare their own food using carbon dioxide and water which are converted into glucose in the presence of sunlight along with the release of oxygen.
B. Denitrification is a process of reduction of nitrate into molecular nitrogen by denitrifying bacteria.
C. Carbon fixation is the reduction and incorporation of inorganic carbon into organic compounds.
D. Cellular respiration is a metabolic reaction in which energy is released from the breakdown of complex substances. Oxygen is used in respiration and carbon dioxide is released. Hence, carbon is returned to its reservoir through cellular respiration.
So, the correct answer is 'cellular respiration'.
Multiple choice biology classification of plants thallophyta cryptograms kingdom plantae

Which of the following is the principal pigment of Phaeophyceae?

  1. Phycocyanin

  2. Phycoerythrin

  3. Fucoxanthin

  4. Chlorophyll
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fucoxanthin is a xanthophyll, with formula CHO. It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color. It is the principal pigment of Phaeophyceae.
Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycoerythrin. It is an accessory pigment to chlorophyll. All phycobiliproteins are water-soluble, so they cannot exist within the membrane-like carotenoids. 

Phycoerythrin (PE) is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in red algae.
Therefore, the correct answer is option C.

Multiple choice biology classification of plants thallophyta cryptograms kingdom plantae

The end product of photosynthesis in green algae, like Chlamydomonas and Spirogyra include

  1. Starch grains

  2. Starch and oil droplets

  3. Proteins

  4. Starch and proteins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Green algae have chloroplasts that contain chlorophyll a and b, giving them a bright green color, as well as the accessory pigments beta carotene and xanthophylls, in stacked thylakoids. The cell walls of green algae usually contain cellulose, and they store carbohydrate in the form of starch. The end products of photosynthesis in these green algae are starch and proteins.

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

Identify the physical change:

  1. Photosynthesis

  2. Respiration

  3. Digestion of food

  4. Melting of Wax
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Melting of wax is a physical change. In a burning candle there are both physical and chemical changes. The burning of the solid wax to form liquid wax and the evaporation of liquid wax to form wax vapour are physical changes. The burning of wax vapour is a physical change.

Multiple choice biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

What happens if the process of photosynthesis in plants for the formation of carbohydrate ?

  1. Reduction of $O _2$
  2. Reduction of $N _2$
  3. Reduction of $CO _2$
  4. Oxidation of $H _@$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Formation of glucose by the unitlization of 6 molecules of carbon dioxide and 12 molecules of water in presence of sunlight in chloroplast is called Photosynthesis. In this process Water is oxidized (loses electrons) in  and carbon dioxide is reduced(gains electrons).
So, the correct option is 'Reduction of CO2'.
Multiple choice biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

Moll's half experiment is performed to show that

  1. Light is needed for photosynthesis.

  2. Chlorophyll is needed for photosynthesis.

  3. Oxygen is evolved during photosynthesis.
  4. CO$ _{2}$ is needed for photosynthesis.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

CO$ _{2}$ is needed for photosynthesis is shown by Moll's half leaf experiment. In this experiment, only that part of the leaf will show blue color which was present outside the bottle because they are able to take carbon dioxide from the stomata of the leaf.

So, the correct answer is option D.

Multiple choice biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

Path of carbon in photosynthesis was found by using 

  1. Centrifugation

  2. Radio isotopes

  3. Fractionation

  4. Chromatography
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Calvin cycle is used for the fixation of carbon dioxide to produce glucose. Radioactive isotopes of carbon (C-14) and phosphorus (P-32) was used to trace the path for the carbon assimilation. A photosynthesizing plant does not strongly discriminate between the most abundant natural carbon isotope C-12 and C-14. During photosynthesis in the presence of 14$CO _2$, the compounds formed become labeled with the radioisotope.

So, the correct answer is option B.

Multiple choice biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases
Moll's half - leaf experiment proves that _________ is essential for photosynthesis to take place. 

  1. chlorophyll
  2. $CO _{2} $

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

In Moll's half leaf experiment a destarched plant is used.Half part of one of the leaves from the plant is inserted into a corked bottle containing either KOH solution or KOH palletes. The plant is then placed in sunlight for a few hours. The leaf is then tested for starch with iodine solution. Part of the leaf that was inserted in the bottle does not turn blue or test positive for starch. This is because $CO _2$ present in the bottle was aborbed by KOH and the bottle was corked to prevent any entry of air.Proving that $CO _2$ is essential for photosynthesis.

So, the correct answer is $CO _2$


Multiple choice biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

Choose the correct answer from the alternatives given.
Molls experiment demonstrates the necessity of which of the following in photosynthesis

  1. water

  2. oxygen

  3. carbon dioxide

  4. chlorophyll
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Molls experiment evidently shows that plants do not form starch when carbon dioxide is not at their disposal, all the carbon dioxide contained in the bottle having been absorbed by the caustic potash solution.

Thus, the correct answer is 'Carbon dioxide.'

Multiple choice biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases
Photochemical phase does not include 

  1. light absorption
  2. water splitting and $ O _{2}$ release

  3. ATP and NADPH formation
  4. $CO _{2}$ fixation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The complete process of photosynthesis is studied under two phases - photochemical phase and biosynthetic phase. Photochemical phase involves absorption of light energy, photolysis of water with the release of $O _{2}$ and production of assimilatory power (i.e. ATP + NADPH).$CO _{2} $ fixation occurs during biosynthetic phase of photosynthesis. 

Multiple choice biology respiration and energy transfer respiratory quotient-basic respiration-plants respiratory quotient

${Q _{10}}$ is

  1. Respiratory coefficient

  2. Photosynthetic coefficient

  3. Photosynthetic yield

  4. Temperature coefficient
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The respiratory quotient (or RQ or respiratory coefficient), is a dimensionless number used in calculations of basal metabolic rate (BMR), when estimated from carbon dioxide production.
RQ = CO$ _{2}$ eliminated / O$ _{2}$ consumed. Thus, option A is incorrect. Photosynthetic coefficient is the specific light spectrum at which chlorophyll absorbs light. Thus, option B is wrong. Photosynthetic yield is the quantity of the end product of the photosynthesis. Thus, option C is wrong. The temperature coefficient (Q$ _{10}$) represents the factor by which the rate (R) of a reaction increases for every 10-degree rise in the temperature (T). The rate (R) may represent any measure of the progress of a process. Thus option D is correct.

Multiple choice biology respiration and energy transfer respiratory quotient-basic respiration-plants respiratory quotient

R.Q. of an actively photosynthesizing tissue is

  1. Infinity.

  2. < 1.

  3. > 1.

  4. Zero.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

During aerobic respiration, O$ _2$ is consumed and CO$ _2$ is released. The ratio of the volume of CO$ _2$ evolved to the volume of O$ _2$ consumed in respiration is called as the respiratory quotient (RQ) or respiratory ratio. Thus, the following expression is used to calculate the value of RQ.
RQ = volume of CO$ _2$ evolved/ volume of O$ _2$ consumed.
In an actively photosynthesizing tissue, the net volume of carbon dioxide evolved (i.e., volume of carbon dioxide produced in respiration minus that utilised in photosynthesis) is equal to net volume of oxygen (i.e., volume of oxygen consumed in respiration minus that evolved in photosynthesis).