Photosynthesis In Higher Plants(12th Grade > Biology ) Questions and answers for exam Preparation

12th Grade > Biology

PHOTOSYNTHESIS IN HIGHER PLANTS MCQs

Total Questions : 59 | Page 5 of 6 pages

_{2}

fixation occurs within the stroma.

True
False
glycolytic
Krebs cycle

Discuss Question

Answer: Option A. -> True
:
A
CO

_{2}

fixation is a part of the Calvin cycle, which occurs in the stroma of the chloroplasts.

Question 42. What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

Bacteria released excess carbon dioxide in these areas.
Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
Bacteria congregated in these areas because these areas had the most oxygen being released.
Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths.

Discuss Question

Answer: Option C. -> Bacteria congregated in these areas because these areas had the most oxygen being released.
:
C
Engelmann used oxygen loving bacteria to grow on the algae. The bacteria congregating in the region of the red and blue light indicated that there was more oxygen being produced in these areas, indicating there was more photosynthetic activity in these areas. Thus Engelmann concluded that the red and blue light of the visible spectrum generate more photosynthetic activity than other parts of the visible spectrum.

Question 43. The law of limiting factors was proposed with particular reference to photosynthesis. Identify the scientist, who proposed this law?

Calvin
Weismann
Emerson
Blackman

Discuss Question

Answer: Option D. -> Blackman
:
D
Law of limiting factor was proposed by F.F Blackman (1905). It is stated that “when a process is conditioned as to its rapidity by a number of separate factors, the rate of the process is limited by the pace of the slowest factor.” (that is factor present minimum amount)

Question 44. Light-driven electron transport in the chloroplast pumps H+ into the intermembrane space between the outer and inner membranes.

True
False
glycolytic
Krebs cycle

Discuss Question

Answer: Option B. -> False
:
B
Light-driven electron transport in the chloroplast pumps H+ from the stroma into the thylakoid lumen.

Question 45. During photosynthesis, photons raise electrons to higher energy levels. These excited electrons belong to what compound?

H2O
ATP
RuBP
Chlorophyll

Discuss Question

Answer: Option D. -> Chlorophyll
:
D
The chlorophyll molecules undergo photoexcitation and release their electrons.

Question 46. The special structure present in C₄ plants is

Thin cuticle
Multi-layered epidermis
Kranz type body
One-layered epidermis

Discuss Question

Answer: Option C. -> Kranz type body
:
C
In C₄plants, characteristic Kranz anatomy is found. Vascular bundles are surrounded by two rings of cells
(i) Bundle sheath cells contain starch rich chloroplast, lacking grana.
(ii)Mesophyll cell, which does not distinguish into spongy and palisade parenchyma

Question 47. Which enzyme fixes CO₂ in Calvin cycle?

RUBP carboxylase
PEP carboxylase
Carbonic anhydrase
Hexokinase

Discuss Question

Answer: Option A. -> RUBP carboxylase
:
A
RuBP carboxylase catalyses the reaction between CO₂ and ribulose biphosphate (RuBP) in the Calvin cycle.

Question 48. What is the primary function of the Calvin cycle?

use ATP to release carbon dioxide
use NADPH to release carbon dioxide
split water and release oxygen
synthesize simple sugars from carbon dioxide

Discuss Question

Answer: Option D. -> synthesize simple sugars from carbon dioxide
:
D
In the Calvin cycle, carbon dioxide is fixed to an organic substrate and then sugars are formed.This is a biosynthetic cycle.

Question 49. In an experiment, demonstrating the evolution of O₂ in Hydrilla, sodium bicarbonate is added to water in the experimental setup. If all other conditions are favorable, what would be the end result?

Amount of oxygen evolved decreases as carbon dioxide in water is absorbed by sodium bicarbonate.
Amount of oxygen evolved increases as the availability of CO2 increases.
Amount of oxygen evolved decreases as the availability of carbon dioxide increases.
Amount of O2 evolved increases as CO2 in water is absorbed by sodium bicarbonate.

Discuss Question

Answer: Option B. -> Amount of oxygen evolved increases as the availability of CO2 increases.
:
B
The addition of NaHCO₃to water in a given experimental set up causes the availability of more carbon dioxide for photosynthesis. Thus amount of O₂ evolved increases.

Question 50. During photosynthesis,

Oxygen evolved comes from CO2
ATP is formed
ATP is not formed
Water is required as medium but it does not take part in photosynthesis.

Discuss Question

Answer: Option B. -> ATP is formed
:
B
ATP is formed during phosphorylation. Water does take part in photosynthesis, oxygen comes from water not from CO₂.