Photosynthesis in Higher Plants

With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?

1. Increasing atmospheric CO2 concentration up to 0.05% can enhance CO2 fixation rate.
2. C3 plants respond to higher temperature with enhanced photosynthesis while C4 plants have much lower temperature optimum.
3. Tomato is a greenhouse crop which can be grown in CO2-enriched atmosphere for higher yield.
4. Light saturation for CO2 fixation occurs at 10% of full sunlight.

Phosphoenol pyruvate (PEP) is the primary CO2 acceptor in

1. C4 plants
2. C2 plants
3. C3 and C4 plants
4. C3 plants

In a chloroplast the highest number of protons are found in

1. intermembrane space
2. antennae complex
3. stroma
4. lumen of thylakoids.

Emerson's enhancement effect and Red drop have been instrumental in the discovery of

1. photophosphorylation and cyclic electron transport
2. oxidative phosphorylation
3. photophosphorylation and non-cyclic electron transport
4. two photosystems operating simultaneously.

A plant in your garden avoids photorespiratory losses, has improved water use efficiency, shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilisation. In which of the following physiological groups would you assign this plant?

1. CAM
2. Nitrogen fixer
3. C3
4. C4

The process which makes major difference between C3 and C4 plants is

1. glycolysis
2. Calvin cycle
3. photorespiration
4. respiration.

In photosynthesis, the light-independent reactions take place at

1. photosystem II
2. stromal matrix
3. thylakoid lumen
4. photosystem I.

Bundle sheath cells :

1. lack both RuBisCo and PEP carboxylase
2. are rich in PEP carboxylase
3. are rich in RuBisCo
4. lack RuBisCo

Read the following four statements (A – D). How many of the above statements are right?

1. Two
2. Three
3. Four
4. One

A process that makes important difference between C3 and C4 plants is

1. transpiration
2. glycolysis
3. photosynthesis
4. photorespiration.

The correct sequence of cell organelles during photorespiration is

1. chloroplast, Golgi-bodies, mitochondria
2. chloroplast, rough endoplasmic reticulum, dictyosomes
3. chloroplast, peroxisome, mitochondria
4. chloroplast, vacuole, peroxisome.

In Kranz anatomy, the bundle sheath cells have

1. thin walls, many intercellular spaces and no chloroplasts
2. thick walls, no intercellular spaces and large number of chloroplasts
3. thin walls, no intercellular spaces and several chloroplasts
4. thick walls, many intercellular spaces and few chloroplasts.

CAM helps the plants in

1. conserving water
2. secondary growth
3. disease resistance
4. reproduction.

Read the following four statements, (i), (ii), (iii) and (iv) and select the right option having both correct statements. Statements : (i) Z scheme of light reaction takes place in presence of PS I only. (ii) Only PS I is functional in cyclic photophosphorylation. (iii) Cyclic photophosphorylation results into synthesis of ATP and NADPH2. (iv) Stroma lamellae lack PS II as well as NADP reductase.

1. (ii) and (iv)
2. (i) and (ii)
3. (ii) and (iii)
4. (iii) and (iv)

Kranz anatomy is one of the characteristics of the leaves of

1. potato
2. wheat
3. sugarcane
4. mustard

Study the pathway given below: [figure] In which of the following options correct words for all the three blanks A, B and C are indicated?

1. A Fixation, B Transamination, C Regeneration
2. A Decarboxylation, B Reduction, C Regeneration
3. A Carboxylation, B Decarboxylation, C Reduction
4. A Fixation, B Decarboxylation, C Regeneration

PGA as the first CO2 fixation product was discovered in photosynthesis of

1. bryophyte
2. gymnosperm
3. angiosperm
4. alga

C4 plants are more efficient in photosynthesis than C3 plants due to

1. higher leaf area
2. presence of larger number of chloroplasts in the leaf cells
3. presence of thin cuticle
4. lower rate of photorespiration

Cyclic photophosphorylation results in the formation of

1. ATP and NADPH
2. ATP, NADPH and O2
3. ATP
4. NADPH.

Stroma in the chloroplasts of higher plants contains

1. light-dependent reaction enzymes
2. ribosomes
3. chlorophyll
4. light-independent reaction enzymes.

Electrons from excited chlorophyll molecule of photosystem II are accepted first by

1. quinone
2. ferredoxin
3. cytochrome-b
4. cytochrome-f

The C4 plants are photosynthetically more efficient than C3 plants because

1. the CO2 efflux is not prevented
2. they have more chloroplasts
3. the CO2 compensation point is more
4. CO2 generated during photorespiration is trapped and recycled through PEP carboxylase

In leaves of C4 plants malic acid synthesis during CO2 fixation occurs in

1. bundle sheath
2. guard cells
3. epidermal cells
4. mesophyll cells

In the leaves of C4 plants, malic acid formation during CO2 fixation occurs in the cells of

1. bundle sheath
2. phloem
3. epidermis
4. mesophyll

The first acceptor of electrons from an excited chlorophyll molecule of photosystem II is

1. iron-sulphur protein
2. ferredoxin
3. quinone
4. cytochrome

During photorespiration, the oxygen consuming reaction(s) occur in

1. stroma of chloroplasts
2. stroma of chloroplasts and mitochondria
3. stroma of chloroplasts and peroxisomes
4. grana of chloroplasts and peroxisomes

In photosystem I, the first electron acceptor is

1. an iron-sulphur protein
2. ferredoxin
3. cytochrome
4. plastocyanin

As compared to a C3-plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by C4-plants?

1. Two
2. Six
3. Twelve
4. Zero

Photosynthetic Active Radiation (PAR) has the following range of wavelengths.

1. 340–450 nm
2. 400–700 nm
3. 500–600 nm
4. 450–950 nm

Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because

1. effective pumping of CO2 into bundle sheath cells
2. RuBisCo in C4 plants has higher affinity for CO2
3. four carbon acids are the primary initial CO2 fixation products
4. the primary fixation of CO2 is mediated via PEP carboxylase.