Photosynthesis

Question 1

Statement 1: Joseph Priestley (1733-1804) in 1770 performed a series of experiments that revealed the essential role of air in the growth of green plants.
Statement 2: Priestley discovered oxygen in 1774.

Answer 1

Both are correct statements

Question 2

Using a similar setup as the one used by……….. but by placing it once in the dark and once in the sunlight………….. (1730-1799) showed that………..is essential for photosynthesis

Answer 2

Priestley
Jan Ingenhousz
Sunlight

Question 3

Assertion: it is only the green part of the plants that could release oxygen.
Reason: small bubbles were formed around the green parts while in the dark they did not

Answer 3

Both are correct and R is correct explanation of A

Question 4

Statement 1: 1854 Julius von Sachs provided evidence for production of glucose when plants grow.
Statement 2: He found that the green parts in plants is where glucose is made, and that the glucose is usually stored as starch.

Answer 4

Both statements are correct

Question 5

Statement 1: T.W Engelmann (1843 – 1909). Using a prism he split light into its spectral components and then illuminated a green alga, Cladophora, placed in a suspension of anaerobic bacteria.
Statement 2: bacteria accumulated mainly in the region of blue and red light of the split spectrum.

Answer 5

Statement 1 is incorrect and 2 is correct
Aerobic bacteria were used

Question 6

The empirical equation representing the total process of photosynthesis for oxygen evolving organisms was then understood as:

Answer 6

CO2+ H2O + Light —————> [ CH2O] + O2

Question 7

Cornelius van Niel (1897-1985), who, based on his studies of purple and green bacteria, demonstrated

Answer 7

2H2A +CO2 + light ———————> 2A + CH2O + H2O

Question 8

O2 evolved by the green plant comes from H2 O, not from carbon dioxide.
True or false

Answer 8

True

Question 9

Statement 1: There is a clear division of labour within the chloroplast.
Statement 2: The membrane system is responsible for trapping the light energy but not for the synthesis of ATP and NADPH.

Answer 9

Statement 1 is correct but statement 2 is incorrect
The membrane system is responsible for trapping the light energy and also for the synthesis of ATP and NADPH.

Question 10

In stroma, enzymatic reactions synthesise sugar, which in turn forms………

Answer 10

starch

Question 11

Colour
Chlorophyll a
chlorophyll b
xanthophylls
carotenoids

Answer 11

bright or blue green in the chromatogram

yellow green

yellow

yellow to yellow-orange

Question 12

Statement 1: Light reactions or the ‘Photochemical’ phase include light absorption, water splitting, oxygen release but not the formation of high-energy chemical intermediates, ATP and NADPH.
Statement 2: Photosystem I (PS I) and Photosystem II (PS II). These are named in the sequence of their discovery, and not in the sequence in which they function

Answer 12

Statement 1 is incorrect and statement 2 is correct

Light reactions or the ‘Photochemical’ phase include light absorption, water splitting, oxygen release and the formation of high-energy chemical intermediates, ATP and NADPH.

Question 13

PS I the reaction centre chlorophyll a has an absorption peak at……….hence is called……….while in PS II it has absorption maxima at………and is called……….

Answer 13

700 nm P700

680 nm P680

Question 14

In photosystem II the reaction centre chlorophyll a absorbs 680 nm wavelength of …….. light causing electrons to become excited and jump into an orbit farther from the atomic nucleus.

Answer 14

red

Question 15

This movement of electrons is uphill in terms of an oxidation-reduction or redox potential scale.
True or false

Answer 15

False
Downhill

Question 16

Statement 1: lamellae of the grana have both PS I and PS II
Statement 2: stroma lamellae membranes lack PS II as well as NADP reductase enzyme.

Answer 16

Both are correct

Question 17

Cyclic photophosphorylation also occurs when only light of wavelengths beyond………..are available for excitation.

Answer 17

680 nm

Question 18

primary accepter of electron which is located towards the outer side of the membrane transfers its electron…………..

Answer 18

not to an electron carrier but to an H carrier.

Question 19

Chemiosmosis requires
4 items

Answer 19

membrane, a proton pump, a proton gradient and ATP synthase.

Question 20

Statement 1: immediately after light becomes unavailable, the biosynthetic process continues for some time, and then stops.
Statement 2: If then, light is made available, the synthesis starts again.

Answer 20

Both statements are correct

Question 21

The use of radioactive………… by………… in algal photosynthesis studies led to the discovery that the first CO2 fixation product was a 3-carbon organic acid known as……..

Answer 21

14C
Melvin Calvin
3 phosphoglyceric acid

Question 22

The studies very unexpectedly showed that the acceptor molecule was a 5-carbon ketose sugar –………..

Answer 22

ribulose bisphosphate (RuBP).

Question 23

………….. is the most crucial step of the Calvin cycle where CO2 is utilised for the carboxylation of RuBP.

Answer 23

Carboxylation

Question 24

Statement 1:Reduction involve utilisation of 2 molecules of ATP for phosphorylation and two of NADPH for reduction per CO2 molecule fixed.
Statement 2: 6 turns of the cycle are required for the formation of one molecule of glucose from the pathway.

Answer 24

Both statements are correct

Question 25

The regeneration steps require………. ATP for phosphorylation to form RuBP

Answer 25

one

Question 26

Hence for every CO2 molecule entering the Calvin cycle, 3 molecules of…….. and 2 of……..are required.

Answer 26

ATP NADPH

Question 27

Statement 1: Plants that are adapted to dry tropical regions have the C4 pathway.
Statement 2: Though these plants have the C4 oxaloacetic acid as the first CO2 fixation product they use the C3 pathway or the Calvin cycle as the main biosynthetic pathway.

Answer 27

Both statements are correct

Question 28

The bundle sheath cells may form several layers around the vascular bundles;
they are characterised by having(3 characters)

Answer 28

large number of chloroplasts
thick walls impervious to gaseous exchange
no intercellular spaces.

Question 29

Statement 1: RuBisCO has a much greater affinity for CO2 when the CO2 : O2 is nearly equal. Statement 2: This binding is competitive. It is the relative concentration of O2 and CO2 that determines which of the two will bind to the enzyme.

Answer 29

Both statements are correct

Question 30

RuBP instead of being converted to 2 molecules of PGA binds with O2 to form one molecule of……….. and……………… (2 Carbon) in a pathway called photorespiration

Answer 30

phosphoglycerate

phosphoglycolate