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PHOTOSYNTHESIS IN HIGHER PLANTS

A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 B 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Section-A

1.Hexose monophosphate pathway takes place in

Endoplasmic reticulum
Cristae
Cytoplasm
Mitochondrial matrix
HMP pathway occurs in cytoplasm of cell.

2.3-PGA is first stable product in

Carbon-reduction cycle
Photorespiration
Light reaction
All of these
3-phosphoglyceric acid (3-PGA) is the first stable product of Calvin-Bensen cycle or $C_3$-cycle or carbon-reduction cycle.

3.In the given chart of photophosphorylation. What does ‘A’ represent?
$Fd→A→Cyt→PC→e^-→$
$P_{700}→e^-→e^-→e^-→Fd$

PC
FRS
PQ
Cyt–$a_3$
Plastoquinone transfer electron from photo system-II to photo system-I. Electrons released from $P_{700}$ or photo system-I moves through Fe-S, plastoquinone, cytochrome and plastocyanin and are recycled to $P_{700}$. In this process, only ATP is produced but no oxygen produced.

4.During photosynthesis,

Oxygen evolved comes from carbon dioxide
ATP is formed
ATP is not formed
Water is required as medium but it does not take part in photosynthesis
ATP is formed during photophosphorylation. Water does takes part in photosynthesis-oxygen comes from water not from carbon dioxide.

5.Scientist believed that since the first product was __A__ acid, the primary acceptor would be __B__ carbon compound; they spent many years trying to identify a 2-carbon compound before they discovered __C__ carbon compound (RuBP).
Complete the given statement with the correct combination of options

A-$C_3$; B-2, C-5
A-$C_3$; B-5, C-2
A-$C_4$; B-5, C-2
A-$C_4$; B-2, A-5
A-$C_3$, B-2, C-5

6.In the process of photosynthesis, water molecule breaks during

Red drop
Photolysis
Phosphorylation
Carbon assimilation
Photolysis is the phenomenon of breaking up of water into hydrogen and oxygen in the illuminated chloroplasts. It is also called, photocatalytic splitting of water. It requires light energy, an oxygen evolving complex and an electron carrier. It also requires the ions, $CI^-,Mn^{2+}$

7.Proton gradient is broken down due to

Movement of electrons across the membrane to stroma
Movement of electrons across the membrane to lumen
Movement of proton across the membrane to lumen
Movement of proton across the membrane to stroma
Movement of protons across the membrane to stroma.
Proton gradient is important because it is the break down of this gradient that leads to release of energy. The gradient is broken down due to movement of protons across the membrane to the stroma through the transmembrane channel of the $F_0$ of the ATPase.
The energy released during the breaking down of proton gradient is used in formation of ATP

8.Basic features of Kranz anatomy of $C_4$-plant is presence of

Chloroplast in bundle sheath cells
Chloroplast in Mesophyll and epidermal cells
Typical granal chloroplasts in bundle sheath cells and rudimentary chloroplasts in mesophyll cells
Rudimentary chloroplasts in bundle sheath cells and typical granal chloroplasts in mesophyll cells
Kranz anatomy shows presence of rudimentary chloroplasts in bundle sheath cells and typical granal chloroplasts in mesophyll cells.

9.Which of the following characteristics out of A, B and C are exhibited by $C_4$-plants?
A. Kranz anatomy
B. The product of photosynthesis is oxaloacetic acid
C. Both PEP carboxylase and ribulose-bisphosphate carboxylase act as carboxylating enzymes.

Only A and B, but not C
Only B and C, but not A
Only A and C, but not B
All A, B and C
$C_4$-plants are characterized by Kranz type of anatomy, i.e., chloroplast containing mesophyll cells and bundle sheath cells. The phosphoenol pyruvate in mesophyll cells combine carbon dioxide in presence of PEP carboxylase and forms oxaloacetic acid. The product of photosynthesis is starch.

10.Liberation of oxygen when green cells in water are exposed to sunlight in presence of suitable acceptor is called

Arnon’s reaction
Emerson’s enhance effect
Blackman’s reaction
Hill’s reaction
Hill’s reaction/photochemical/light reaction is initiated when specific light is absorbed by group of chlorophyll molecules primarily concerned with light harvesting.

11. I. It is the characteristic of $C_4$-plants
II. It is the characteristic of $C_3$-plants
III. It occurs in chloroplast
IV. It occurs in day time
V. It occurs in night
Select the correct options in relation to photorespiration

Correct option-I, IV; Incorrect option-II, III, IV
Correct option-II, III, IV; Incorrect option-I, V
Correct option-I, II, III; Incorrect option-IV, V
Correct option-IV, V; Incorrect option-I, II, III
The process of photorespiration was firstly discovered in tobacco plant. It is the light dependent day time process of oxygenation of RuBP. It takes place in the chloroplast and characteristic of $C_3$-plants

12.Organelles involved in photorespiration is/are
I. chloroplast
II. peroxisomes
III. mitochondria
Choose the correct option

I and II
II and III
III and I
I, II and III
In photorespiration, the three subcellular compartments namely, the chloroplast, peroxisomes and mitochondria are involved

13.Photosynthesis is maximum in

Green light
Blue followed by red right
Red followed by blue light
Blue light
Maximum photosynthetic rate has been observed in the full spectrum. Regarding the effect of the different wavelengths, maximum photosynthesis occurs in red light (660 nm) second maximum in blue (440 nm) and minimum in green.

14.CAM pathway is observed in

Pineapple
Maize
Sunflower
Sugarcane
CAM plants fix $CO_2$ at night and from malate which stored in large vacuole of mesophyll cells till next day. These plants use PEP carboxylase. The malate release $CO_2$ in day for use in Calvin cycle in same cell, e.g., family-Euphorbiaceae, Asclepiadaceae, etc.

15.Compensation point refers to

Little photosynthesis
Beginning of photosynthesis
Rate of photosynthesis equals to the rate of respiration
None of the above
Compensation point refers to alight intensity at which the rate of respiration by a photosynthetic cell or organ is equal the rate of photosynthesis. There is no net gain or loss of oxygen or carbon dioxide from the structure.

16.In $C_4$-plants, the bundle sheath cells

Have thin walls to facilitate gaseous exchange
Have large intercellular spaces
Are rich in PEP carboxylase
Have a high density of chloroplasts
In the leaves of $C_4$-plants, the vascular bundles are surrounded by bundle sheath of larger parenchymatous cells, which in turn are surrounded by mesophyll cells. Bundle sheath cells have a high density of larger chloroplasts which always lack grana, whereas chloroplasts of mesophyll cells are smaller.

17.What percentage of solar radiation that hits the earth’s atmosphere ever reaches the surface?

92%
2%
42%
22%
About 42% of solar radiation hits the earth’s atmosphere.

18.Which of the following is wrongly matched?

Sorghum – Kranz anatomy
PEP carboxylase – Mesophyll cells
Blackman – Law of limiting factors
Photosystem-II – $P_{700}$
Pigment system-II (PS-II) has absorption maxima at 680 nm and is called $P_{680}$.

19.Which one is essential for the respiration as well as photosynthesis?

Rubisco
Plastocyanin
Ubiquinone
Cytochrome
Cytochromes are iron containing pigments. These act as electron transporter or electron acceptor in respiration and photosynthesis both.

20.Photochemical reactions in the chloroplast are directly involved in

Photolysis of water and formation of ATP
Formation of PGA
Synthesis of starch and lipid
Fixation of PEP
Photochemical reaction is also known as light reaction because it takes place in the presence of light in the grana portion of chloroplast. In this reaction, photolysis of water takes place, which generates ATP and NADPH

21.RuBP+$CO_2$+Rubisco → x. In the given
Identify x in the given

2×2 PGA
2×3 PGA
2×4 PGA
2×1 PGA
In the Calvin cycle, the RuBP combines with the $CO_2$ to form 2 molecules of 3 phosphoglyceric acid and the reaction is catalysed by RuBisCo
RuBP+$CO_2$ + RuBisCo → 2×3PGA

22.Identify the incorrect statement with respect to Calvin cycle.

The carboxylation of RuBP is catalysed by Rubisco
The first stable intermediate compound formed is phosphoglycerate
18 molecules of ATP molecules of ATP are synthesized during carbon fixation
NADPH + $H^+$ produced in light reaction is used to reduce diphosphoglycerate
In Calvin cycle, 18 molecules of ATP are used in carbon fixation. The overall reaction of Calvin cycle represents as
$6RuBP+6CO_2+18ATP+12NADPH→$
$6RuBP+C_6 H_{12} O_6+18ADP+18P+12NADP^+$

23.Identify from the following, a characteristic pigment, which contains copper containing protein

Plastoquinone
Ferredoxin
Cytochrome
Plastocyanin
Plastocyanin is a small (10.5 KDa), water soluble, copper containing protein that transfer electrons between the cytochrome-$b_6-f$ complex and $P_{700}$.

24.Oxaloacetic acid changes to the malic acid by the action of

Oxaloacetic dehydrogenase
Malic dehydrogenase
PEP dehydrogenase
RMP dehydrogenase
After the fixing of $CO_2$ to Oxaloacetic Acid (OAA) in $C_4$ cycle, the oxaloacetic acid changes into the malic aspartic acid
OAA + NADPH + Malic acid dehydrogenase → Malic acid + $NADP^+$
$OAA + NH_3 + NADPH$ + Transaminase → Aspartic acid $+ NADP^++H_2 O$
Both of these reactions occur in mesophyll cell

25.‘Hatch and Slack’ cycle is found in

$C_4$-plants
$C_3$-plants
Both of these
None of these
M D Hatch and C R Slack found that in certain plants growing in tropical climates, the first product of photosynthesis is a $C_4$-compound instead of a $C_3$-compound. These plants are now known as $C_4$- plants or Hatch and Slack type plants. The $C_4$-plants show Kranz type anatomy, e.g., sugarcane, Corn, Euphorbia, etc.

26.In leaves of $C_4$-plants, malic acid synthesis during carbon dioxide fixation occurs in

Epidermal cells
Mesophyll cells
Bundle sheath cells
Guard cells
In $C_4$-plants, the Hatch and Slack pathway involves two carboxylation reaction, one taking place in chloroplast of mesophyll cells and other in chloroplast of bundle sheath cells.

27.Which of the following is the formula of chlorophyll-a?

$C_{55} H_{70} O_2 N_4 Mg$
$C_{55} H_{72} O_5 N_4 Mg$
$C_{55} H_{70} O_5 N_4 Mg$
$C_{55} H_{72 }O_2 N_4 Mg$
The empirical formula of chlorophyll-a is $C_{55} H_{72} O_5 N_4 Mg$.

28.The molecule present in the reaction centre of photosystem is

Chlorophyll-a
Chlorophyll-b
Chlorophyll-c
Chlorophyll-d
Chlorophyll-a.
The pigments are organised into two discrete photochemical Light Harvesting Completes (LHC) within the Photosystem I (PS-I) and Photosystem II (PS-I). These are named in the sequence of their discovery, and not in the sequence in which they function during the light reaction. The LHC are made up of hundreds of pigment molecules bounded to proteins. Each photosystem has all the pigments (except one molecule of chlorophyll-a) forming a light harvesting system known as antenna

29.Photosynthesis in $C_4$-plants is relatively less limited by atmospheric carbon dioxide levels because

Four carbon acids are the initial carbon dioxide acceptors
The primary fixation of carbon dioxide is mediated via PEP carboxylase
Effective pumping of $CO_2$ into bundle sheath cells
Rubisco in $C_4$- plants has higher affinity for $CO_2$
The fixation of carbon dioxide in $C_4$-plants takes place in two places and by two different organic compounds. Phosphoenol pyruvate (PEP) is found in mesophyll cells, which primarily fixes atmospheric carbon dioxide into oxaloacetic acid (4C). RUBISCO is present in bundle sheath cells, where final fixation of carbon dioxide in hexose sugar takes place. Carbon dioxide is primarily fixed by PEP carboxylase because this enzyme has greater affinity to carbon dioxide than RUBISCO.

30.Transport of $C_4$ acid from mesophyll cells to the bundle sheath cell takes place through

Cell membrane
Cell wall
Plasmodesmata
Osmosis
Mesophyll cells and bundle sheath cells which are connected through plasmodesmata, through which organic acid like malic acid, pyruvic acid can translocate. Malic acid translocate from the mesophyll cells to bundle sheath cell and pyruvic acid translocate from the bundle sheath cells to mesophyll cells

31.In $C_3$ cycle for the fixation of every $CO_2$ molecules, the reduction and regeneration steps required

3 ATP and 2 $NADPH_2$
2 ATP and 2 $NADPH_2$
2 ATP and 3 $NADPH_2$
3 ATP and 3 $NADPH_2$
For every $CO_2$ molecule entering the Calvin cycle (the reduction and regeneration steps), three molecules of ATP and two molecules of $NADPH+H^+$ are required.

32.Large number of chloroplast are present in which of the following cells?

Parenchymatous cell
Mesophyll cell
Peroxisomal cell
Cell wall
Chloroplasts are found in the mesophyll cells of the leaves. Leaves have a maximum number of chloroplasts

33.Living organisms have the capability of extracting energy from

Reducible substances
Oxidising substances
ADP
AMP
Living organisms have the capability of extracting energy from oxidisable substances and store this the in form of bond energy. Special substances like ATP, carry this energy in their chemical bonds. The process through which ATP is synthesised by cells (in mitochondria and chloroplast) is named oxidative phosphorylation

34.Identify the 5-C compound from the given option

RuBP
OAA
3PGA
$NADPH_2$
RuBP (Ribulose, 1-5 diphosphate) is the 5 carbon compound in which the ribose sugar is present

35.Bacterial photosynthesis involves

Both PS-I and PS-II
Either PS-I or PS-II
PS-I only
PS-II only
Bacterial photosynthesis involves only photosystem-I(PS-I) and cyclic photophosphorylation. It is not connected with photolysis of water, therefore, oxygen is not evolved. This synthesizes only ATP.

Section-B

36.Products of light reaction are ATP, __A__ and $O_2$. Of these, __B__ diffuses out of the chloroplast, while ATP and NADPH are used to derive the process leading to the synthesis of food more accurately, __C__
What does the blanks A-C refers here?

A-NADP; B-$O_2$; C-lipid
A-$NADPH_2$; B-$O_2$; C-amino
A-$NAD^+$; B-$O_2$; C-sugars
A-NADPH + $H^+$; B-$O_2$; C-sugars
Product of light reactions are ATP, NADPH and $O_2$. Of these $O_2$ diffuse out of the chloroplast, while ATP and NADPH are used to drive the process leading to synthesis of food, sugars. $NADPH + H^+,O_2$ etc.

37.PS-I and PS-II were discovered by

Robert Emerson
Blackman
Robert Mayer
Arnon
Robert Emerson discovered Pigment System-I (PS-I) and Pigment System-II (PS-II).

38.Of the total incident solar radiation the proportion of PAR is

About 60%
Less than 50%
More than 80%
About 70%
PAR (Photosynthetically active radiation) designates the spectral range of solar radiation from 400 to 700 nm that photosynthetic organisms are able to use in the process of photosynthesis. Of the total incident solar radiation the proportion of PAR is less than 50%

39.The Z scheme of electron transport is

Cyclic photophosphorylation
Non-cyclic photophosphorylation
Both Cyclic and Non-cyclic photophosphorylation
Where only photosystem pigment-I is involved
Scheme of transfer of electrons, starting from the PS-II, uphill to the acceptor, down the electron transport chain to PS-I, excitation of electrons, transfer to another acceptor and finally down hill to $NADP^+$ causing it to be reduced to $NADPH+H^+$ is called the Z scheme, due to its characteristic shape. This shape is formed when all the carriers are placed in a sequence on a redox potential scale

40.Within the chloroplast, there is the membranous system consisting of
I. grana
II. stroma lamellae
III. fluid stroma
Choose the correct option

I and II
II and III
I and III
I, II and III
Within the chloroplast, there is the membranous system (grana, stroma lamellae) and fluid it is called stroma

41.What is the name given to the flattened membranous sacs which are embedded in the matrix of the chloroplast?

Thylakoids
Granum
Stroma
Mesophyll cells
In the matrix or stroma, there are embedded a number of flattened membranous sacs called thylakoids or lamellae. Membranes of thylakoids are called fret membranes. They are made up of both proteins and unsaturated lipids, roughly in the ratio of 50:50

42.Who proposed that $O_2$ comes from water instead from $CO_2$ during photosynthesis?

Von Neil
Engelmann
Blackman
Warburg
Cornelius van Niel (1897-1985) who based on his studies on purple and green bacteria, demonstrated that photosynthesis is essentially a light dependent reaction in which hydrogen from a suitable oxidisable compound reduces carbon dioxide to carbohydrate. This can be expressed by
$2H_2 A+CO_2$ + Light → $2A+CH_2 O+H_2 O$
In green plants, $H_2 O$ is the hydrogen donor and is oxidised to $O_2$ photosynthesis. Some organism do not release $O_2$ during photosynthesis. When $H_2 S$ instead is the hydrogen donor for purple and sulphur bacteria, the oxidation product is sulphur or sulphate depending on the organism and not $O_2$. Hence, he inferred that $O_2$ evolved by green plant comes from $H_2 O$, not from carbon dioxide.

43.In higher plants, the shape of the chloroplast is

Discoid
Cup-shaped
Girdle-shaped
Reticulate
Chloroplasts are the green plastids which take part in photosynthesis and temporary or permanent storage of starch. These are discoid (disc-shaped) in higher plants with diameter of 4-6 μm and thickness of 2-4μm.

44.What is common between chloroplasts, chromoplasts and leucoplasts?

Presence of pigments
Possession of thylakoids and grana
Storage of starch, proteins and lipids
Ability to multiply by a fission-like process
New plastids arise from proplastids by a fission-like process.

45.The functions of chloroplast of membrane system is

Trapping of light energy
Synthesis of ATP
Synthesis of NADPH
All of these
The membranous system is responsible for trapping the light energy that make ATP and NADPH necessary for the starch synthesis

46.The special structure present in $C_4$-plants in

Thin cuticle
Multi-layered epidermis
Kranz type body
One-layered epidermis
In $C_4$-plants, characteristics Kranz anatomy is found. Vascular bundles are surrounded by two rings of cells-
1. Bundle sheath cell contains starch rich chloroplast, lacking grana.
2. Mesophyll cell, which does not distinguished into palisade and spongy parenchyma.

47.Emerson effect explain the phenomenon of

Transpiration
Absorption of water by roots
Photosynthesis
Respiration
Emerson et al, (1957) discovered that far red light (above 680 nm), which is Photosynthetically inefficient can be made efficient by supplementing it with a beam of shorter wavelength (red beam below 680 nm). Further the quantum yield in combined beam (far red+red) is more than sum total of quantum yields in two separate beam. This enhancement in quantum yield by supplementing far red light with red light is called Emerson enhancement effect.

48.Hill reaction occurs in

High altitude plants
Total darkness
Absence of water
Presence of ferricyanide
Hill reaction was discovered by Robert Hill in 1939. It involves the release of oxygen from isolated illuminated chloroplasts when suitable electrons acceptors (e.g., potassium ferricyanide) are added to the surrounding water.

49.Which of the following elements are essential for the photolysis of water?

Ca and Cl
Mn and Cl
Zn and I
Cu and Fe
Photolysis of water means breakdown of water in the presence of sun light. This generates oxygen. Photolysis of water takes place in light reaction and it requires chloride and manganese ions as catalyst.

50.Red light favours the __A__ accumulation. Blue light favours the __B__ accumulation
Here A and B refer to

A-Starch; B-lipid
A-lipid; B-starch
A-carbohydrate; B-cholestrol
A-carbohydrate; B-protein
Maximum photosynthesis occurs in the blue-violet and red region of light spectrum. Red light favours the carbohydrate accumulation, while blue light stimulates protein synthesis