NEET Exam  >  NEET Tests  >  Biology Class 11  >  Test: Biosynthetics Phase - NEET MCQ

Test: Biosynthetics Phase - NEET MCQ


Test Description

25 Questions MCQ Test Biology Class 11 - Test: Biosynthetics Phase

Test: Biosynthetics Phase for NEET 2024 is part of Biology Class 11 preparation. The Test: Biosynthetics Phase questions and answers have been prepared according to the NEET exam syllabus.The Test: Biosynthetics Phase MCQs are made for NEET 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for Test: Biosynthetics Phase below.
Solutions of Test: Biosynthetics Phase questions in English are available as part of our Biology Class 11 for NEET & Test: Biosynthetics Phase solutions in Hindi for Biology Class 11 course. Download more important topics, notes, lectures and mock test series for NEET Exam by signing up for free. Attempt Test: Biosynthetics Phase | 25 questions in 25 minutes | Mock test for NEET preparation | Free important questions MCQ to study Biology Class 11 for NEET Exam | Download free PDF with solutions
Test: Biosynthetics Phase - Question 1

Which of the following statement about dark reaction is correct?

Detailed Solution for Test: Biosynthetics Phase - Question 1

Bisoynthetic phase (Dark or Blackman's reaction) catalyses the assimilation of CO2 to cabohydrates. These reactions occurs in stroma or matrix of chloroplasts and all the enzyme required for the processes are present in the stroma/matrix of choroplasts. These reactions do not require light, instead assimilatory power (ATP and NADPH) produced during photochemical (light) phase is used in fixation and reduction of CO2 However, this should not be construed to mean that they occur in darkness or that they are not light dependent.

Test: Biosynthetics Phase - Question 2

Which of the following products of the light reaction are subsequently used during the biosynthetic phase of photosynthesis?

Detailed Solution for Test: Biosynthetics Phase - Question 2

The correct option is C ATP and NADPH
The biosynthetic phase occurs in the stroma of chloroplast. During this phase, there is fixation of CO2 and synthesis of glucose by utilising ATP and NADPH. ATP and NADPH are assimilatory powers formed during the light reaction of photosynthesis. For the synthesis of one molecule of glucose, 18 ATP and 12 NADPH are utilised.

1 Crore+ students have signed up on EduRev. Have you? Download the App
Test: Biosynthetics Phase - Question 3

Refer to the given diagrammatic of an electron micrograph of a section of chloroplast.

Select the option which correctly depicts the function of parts X, Y and Z.

Detailed Solution for Test: Biosynthetics Phase - Question 3

Light reaction (or photochemical phase) of photosynthesis mainly occur on the grana thylakoids. Dark reaction (or biosynthetic phase) which involve the synthesis of carbohydrates by CO2​ fixation occur in the stroma (or matrix) of chloroplasts. The chloroplast matrix of higher plants stores starches temporarily in the form of starch granules. 

Test: Biosynthetics Phase - Question 4

A sectional view of the chloroplast  is given below. Choose the correct statement for A and B?

Detailed Solution for Test: Biosynthetics Phase - Question 4

A - Thylakoids arearranged in stacks like the piles of coins called grana; 
B - Possess the enzyme required for protein and carbohydrate synthesis 


The space limited by the inner membrane of the chloroplast is called the stroma. The stroma of the chloroplast contains enzymes required for the synthesis of carbohydrates and proteins. It also contains small, double-stranded circular DNA molecules and ribosomes.

A number of organised flattened membranous sacs called the thylakoids, are present in the stroma. Thylakoids are arranged in stacks like the piles of coins called grana (singular: granum) or the intergranal thylakoids.

Test: Biosynthetics Phase - Question 5

Read the given statement and select the correct option. 
Statement 1:
Carboxylation is the most crucial step of Calvin where CO2 is utilised for the carboxylation of RuBP. 
Statement 2: This reaction is catalysed by the enzyme RuBisCO which results in the formation of two molcules of 3-PGA.

Detailed Solution for Test: Biosynthetics Phase - Question 5

Carboxylation is the most crucial step of Calvin cycle where CO2 is utilized for the carboxylation of RuBP through the use of ATP and NADPH generated by the light reactions. The reaction is catalysed by enzyme RuBisCO CO2 combines with RuBP (ribulose-1, 5-biphosphate) to produce a transient intermediate compound called 2-carboxy 3-keto 1,5-biphosphoribotol. The intermediat splits up immediately in the presence of water to form two molecules of 3-phosphoglyceric acid or PGA, which is the first stable product of photosynthesis

Test: Biosynthetics Phase - Question 6

Select the incorrect pair

Detailed Solution for Test: Biosynthetics Phase - Question 6

Both malic acid and asparic acid are 4-carbon compounds formed in the mesophyll cells during C4 cycle. PGA (3-phosphoglyceric acid) is a 3-carbon compound, which is the first stable product of Calvin cycle (C3cycle). RuBP (Ribulose-1,5-biphosphate) is a 5-carbon compound, which is the primary acceptor of CO2 during C3 cycle.

Test: Biosynthetics Phase - Question 7

Read the given statements and select the correct option. 
Statement 1 :
Crassulacean acid metabolism occurs in succulent plants which grow in xeric conditions. 
Statement 2 : Stomata are generally sunken in succulent plants.

Detailed Solution for Test: Biosynthetics Phase - Question 7

Crassulacean acid metabolism is a mechanism of photosynthesis involving double fixation of CO2 which occurs in succulents belonging to Crassulaceae, Cacti, Euphorbias and some other plants of dry habitats. Here, the stomata remains closed during the daytime and opens only at night, e.g Sedum,Kalanchoe,Opuntia. Sunken stomata are deep seated stomata in which subsidiary cells lie above the guard cells. So, the correct answer is 'Both statements are correct'.

Test: Biosynthetics Phase - Question 8

Kranz anatomy is not exhibited by which of the following plants?

Detailed Solution for Test: Biosynthetics Phase - Question 8

Kranz anatomy is shown by C4 plants such as Sorghum, sugarcane, maize, Cyperus rotundus, etc.

Test: Biosynthetics Phase - Question 9

Given figure represents C4​ pathway. Select the suitable option for A, B and C. 

Detailed Solution for Test: Biosynthetics Phase - Question 9

A - Fixation
B - Decarboxylation
C - Regeneration
So, the correct answer (D).

Test: Biosynthetics Phase - Question 10

During fixation of one molecule of CO2​ by C3​ plants, number of ATP and NADPH2​ required are 

Detailed Solution for Test: Biosynthetics Phase - Question 10

For every CO2 molecule entering the Calvin cycle, 3 molecules of ATP and 2 molecules of NADPH are required. To make one molecule of glucose, 6 turns of the cycles are required (6 × 3ATP = 18ATP and 6 × 2NADPH = 12NADPH)

In
6 CO2
18ATP

Out
1 glucose
18ADP 

12NADPH 12NADP, So, the correct answer is ' 3ATP and 2NADPH2'

Test: Biosynthetics Phase - Question 11

Which of the following statement is incorrect regarding the Calvin cycle of C3​ plants?

Detailed Solution for Test: Biosynthetics Phase - Question 11

In C3 plants, bundle sheath cells usually do not contain chloroplasts and the whole C3 cycle operates in mesophyll cells of leaves. in C4 plants showing Hatch-Slack cycle however, intial fixation of  CO2 occurs in mesophyll cells followed by final fixation in bundle sheath cells.

Test: Biosynthetics Phase - Question 12

Select the incorrect statement as far as kranz anatomy is concerned.

Detailed Solution for Test: Biosynthetics Phase - Question 12

Kranz anatomy is a characteristic of C4​ plants. In kranz anatomy, the mesophyll is undifferentiated and its cells occur in concentric layers around vascular bundles. Vascular which are surrounded by large-sized bundle sheath cells which are arranged in a wreath like a manner in one to several layers. The chloroplasts of mesophyll cells are smaller, they have well-developed grana and a peripheral reticulum but no starch. Mesophyll cells possess enzyme PEP case for initial fixation of CO2​. The chloroplasts of the bundle sheath cells are agranal. They possess a peripheral reticulum and starch grains. Bundle sheath cells possess enzyme RuBisCO.

Test: Biosynthetics Phase - Question 13

RuBisCO is

Detailed Solution for Test: Biosynthetics Phase - Question 13

The enzyme RuBisCO carries out photosynthetic carboxylation of RuBP The enzyme was previously called as carboxydismutase. RuBisCO is the most abundant protein of the biological world. RuBisCO is located int the stroma on the outer surface of thylakoid membranes. As it is capable of carrying out both carboxylation and oxygenation and oxygenation reaction in C3 and C4 plants respectively, thus it is correctly named as RuBP carboxylase-oxygenase. 

Test: Biosynthetics Phase - Question 14

The enzyme RuBisCO has _________.

Detailed Solution for Test: Biosynthetics Phase - Question 14

The active site of RuBisCO for carboxylation and oxygenation is the same. The enzyme has more affinity for CO2​ as compared to oxygen. Active oxygenation occurs only when CO2​:O2​ ratio favours it. At hight temperature, concentration of dissolved CO2 in equilibrium with air decreases more than concentration of O2, which favours oxygenation, High temperature occurs in tropical areas. Therefore, tropical plants are the major sufferers. At high temperature, RuBisCo functions as oxygenase and instead of fixing CO, oxidizes RuBP to produce a 3-C phosphoglyceric acid and a 2-C phosphoglycolate. This is the first reaction of photorespiration or C2 cycle.

Test: Biosynthetics Phase - Question 15

Optimum temperature conditions for photosynthesis in C3 and C4 plants are respectively

Detailed Solution for Test: Biosynthetics Phase - Question 15

The Optimum temperature Is 10C−25C for C3, plants and 30°C-45°C for C4 plants.

Test: Biosynthetics Phase - Question 16

In an experiment in which photosynthesis is performed during the day you provide a plant with radioactive carbon dioxide (14CO2) as a metabolic tracer. The 14C is incorporated first into oxaloacetic acid. The plant is best characterised as a

Detailed Solution for Test: Biosynthetics Phase - Question 16

In C4 plants, the first stable photosynthetic product is a 4-carbon compound, i.e., oxaloacetic acid (OAA), which is formed by initial fixation of CO2 by the carboxylation of phosphoenol pyruvate in the mesophyll cells. So, when radioactive 14CO2 is introduced into the reaction, it is first incorporated into the OAA.

In a CAM plant, although the first product formed is OAA, but here the initial CO2 fixation occurs at night.

Test: Biosynthetics Phase - Question 17

Read the given statements and select the correct option.
Statement 1:
Photorespiration interferes with the successful functioning of Calvin cycle.
Statement 2: Photorespiration oxidises ribulose-1,5 biphosphate which is an acceptor of CO2 in Calvin cycle.

Detailed Solution for Test: Biosynthetics Phase - Question 17

Photorespiration (Photosynthetic carbon oxidative or PCO cycle) is the light dependent process of oxygenation of ribulose-1,5-biphosphate (RuBP) and release of CO2 by the photosynthetic organs of a plant. Under normal conditions, in Calvin cycle, carboxylation of RuBP takes place whereas during photorespiration instead of carboxylation, oxygenation of RuBP takes place. This is due to abnormal behaviour of enzyme RuBisCO, which at high temperature (more than 35C), functions as oxygenase (instead of carboxylase). Instead of fixing CO2, it performs oxygenation of RuBP to produce a 3-carbon phosphoglyceric acid (PGA) and a 2-carbon phosphoglycolate. It is the first reaction of photorespiration and can be represented as:

In this way, photorespiration interferes with the successful functioning of Calvin cycle by causing oxygenation of RuBP instead of carboxylation.

Test: Biosynthetics Phase - Question 18

How many ATP and NADPH2​ are respectively produced in the process of photorespiration?

Detailed Solution for Test: Biosynthetics Phase - Question 18

Photorespiratory pathway (or C2​ pathway) results in the release of CO2​ with the utilization of ATP. In the photorespiratory pathway, three is no synthesis of ATP or NADPH.

Test: Biosynthetics Phase - Question 19

Which organelle out of these does not participate in photorespiration?

Detailed Solution for Test: Biosynthetics Phase - Question 19

The site for photorespiration is chloroplast peroxisome and mitochondrion. It is also called photosynthetic carbon oxidative or PCO cycle.

Test: Biosynthetics Phase - Question 20

Study the given graph showing the effect of light intensity on the rate of photosynthesis. Which of the following statement regarding this is correct?

Detailed Solution for Test: Biosynthetics Phase - Question 20

A limiting factor is defined as a factor which is deficient to such an extent that increase in its magnitude directly increaes the rate of the process. In the given graph, rate of photosynthesis initially increaes with an increase in light intesntiy (region A) but soon it levelled off. Thus. initially light intensity was limiting the rate of photosynthesis. Hoever, when light intensity was present in sufficient amounts (region C), rate of photosynthesis did not increase further. This is due to the fact that in region C, some other factor (e.g. CO2 concentration) became the limiting factor. At this region, the rate of photosynthesis could be further enhanced only by the increase in availability of other limiting factor (e.g. CO2)

Test: Biosynthetics Phase - Question 21

The law of limiting factors' was given by _______ in the year _______.

Detailed Solution for Test: Biosynthetics Phase - Question 21

Blackman's (1905) law of limiting factors states that a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value: it is the factor which directly affects the process its quantity is changed.

Test: Biosynthetics Phase - Question 22

Given table shows the CO2​ compensation point and optimum CO2​ concentration for phtosynthesis for C3 ​and C4​ plants.

Select the correct values for A and B.

Detailed Solution for Test: Biosynthetics Phase - Question 22

CO2​ compensation point or threshold value is that concentration of CO2​ at which illuminated plant parts stop absorbing carbon dioxide from their environment, At this value, CO2​ fixed in photosynthesis is equal to CO2​ evolved in respiration and photorespiration. The value is 25-100 ppm in C3​ plants and 0-10 ppm in C4​ plants .The reason for low compensation value for C4​ plants is the greater efficiency of CO2​ fixation through PEP-carboxylase. The optimum CO2​ concentration for C4​ plants is 360 ppm and C3​ plants, it is 450 ppm.  

Test: Biosynthetics Phase - Question 23

When the temperature is increased from minimum to optimum, rate of photosynthesis doubles for every _______ rise in temperature.

Detailed Solution for Test: Biosynthetics Phase - Question 23

The rate of photosynthesis usually increases with an increase in temperature up to 40oC. Above this temperature, the rate of photosynthesis starts decreasing due to the inactivation of enzymes. The minimum temperature at which most plants start photosynthesis is 0o−5oC but it can be as low as - 20oC for lichens and - 35oC for some gymnosperms.The maximum temperature at which photosynthesis can occur is 55oC in some desert plants and 75o for hot spring algae. When the temperature is increased from minimum to optimum, the rate of photosynthesis doubles for every 10oC rise in temperature. 

Test: Biosynthetics Phase - Question 24

Tropical plants have a ______ temperature optimum than the plants adapted to temperate climates.

Detailed Solution for Test: Biosynthetics Phase - Question 24

The C4​ plants respond to higher temperatures and show higher rate of photosynthesis while C3​ plants have a much lower temperature optimum. The temperature optimum for photosynthesis of different plants depends on the habitat that they are adapted to. Tropical plants have a higher temperature optimum than the plants adapted to temperate climates as tropical areas have higher temperature as compared to temperate areas.  

Test: Biosynthetics Phase - Question 25

One scientist cultured Cladophora in a suspension of Azotobacter and illuminated the culture by splitting light through a prism. He observed that bacteria accumulated mainly in the region of:

Detailed Solution for Test: Biosynthetics Phase - Question 25

Using a prism he split light into its spectral components and then illuminated a green alga, Cladophora, placed in a suspension of aerobic bacteria. The bacteria were used to detect the sites of O2 evolution. He observed that the bacteria accumulated mainly in the region of blue and red light of the split spectrum.

190 videos|390 docs|210 tests
Information about Test: Biosynthetics Phase Page
In this test you can find the Exam questions for Test: Biosynthetics Phase solved & explained in the simplest way possible. Besides giving Questions and answers for Test: Biosynthetics Phase, EduRev gives you an ample number of Online tests for practice

Up next

190 videos|390 docs|210 tests
Download as PDF

Up next