Which one of the following is the correct order of electron transport during light reaction in the thylakoid membrane of chloroplast?

• P680 → Cytochrome b₆f → PC → PQ

• P680 → PC →  Cytochrome b₆f → PQ

• P680 → PQ → PC →  Cytochrome b₆f 

• P68 → PQ → Cytochrome b₆f → PC

Which one of the following will be observed when auxin to cytokinin ratio is increased in the culture medium during organogenesis from tobacco pith callus?

• Adventitious roots will form

• Adventitious shoot will form

• There will be no root formation

• There will be no shoot formation

Which one of the following photoreceptors play a role in day length perception and circadian rhythms?

• Zeitupe family

• Cryptochromes

• Phototropins

• UV resistance locus 8

The following statements are made to describe auxin signal transduction pathway, from receptor binding to the physiological response:

A. Auxin response factors (ARFs) are nuclear proteins that bind to auxin response elements (Aux REs) to activate or repress gene transcription.

B. AUX?IAA proteins are secondary regulators of auxin-induced gene expression. Binding of AUX/IAA proteins to the ARF protein blocks its transcription regulation.

C. Auxin binding to TIR1/AFB promotes ubiquitin-mediated degradation and removal of AUX/IAA proteins.

D. Auxin binding to auxin response factors (ARFs) causes their destruction by the 26S proteasome pathway.

Which one of the following combinations of above statements is correct?

• A, B, and C

• A, C, and D

• B, C, and D

• A, B, and D

Match the two columns following asexual reproduction of plants and apomixes:

• A - i; B - ii; C - iii; D - iv

• A - ii; B - iii; C - iv; D - i

• A - ii; B - i; C - iii; D - i

• A - ii; B - i; C - iv; D - iii

Match the following associations involved in dinitrogen fixation with their representative genera.

• A - ii; B - i; C - iv; D - iii

• A - iii; B - i; C - ii; D - iv

• A - i; B - ii; C - iii; D - iv

• A - ii; B - i; C - iii; D - iv

Several transport steps are involved in the movement of photosynthate from the chloroplasts. Following are certain statements regarding the transport of photosynthate:

A. Pentose phosphate formed by photosynthesis during the day is transported from the chloroplast to the cytosol, where it is converted to sucrose.

B. Carbon stored as starch exits the chloroplast at night primarily in the form of maltose and is converted to sucrose in cytosol.

C. During short-distance transport, sucrose moves from producing cells in the mesophyll to cells in the vicinity of the sieve elements in the smallest veins of the leaf.

D. In the process of phloem loading, sugars are transported into phloem parenchyma cells.

Which one of the following combinations of above statements is correct?

• A and B

• B and C

• C and D

• A and D

Phenylalanine, a precursor of most of the phenolics in higher plants is a product of which one of the following pathways?

• Shikimic acid pathway

• Malonic acid pathway

• Mevalonic acid pathway

• Methylerythritol pathway

Light reactions of photosynthesis are carried out by four major protein complexes: Photosystem I (PSI), photosystem II (PSII), the cytochrome b₆f complex and ATP synthase. The following are certain statements on PSI:

A. PSI reaction centre and PSII reaction centre are uniformly distributed in the granal lamellae and stromal lamellae.

B. The electron donor for the P700 of PSI is plastocyanin and electron acceptor of P700* is a chlorophyll known as A₀.

C. The core antenna and P700 are bound to two key proteins PsaA and PsaB.

D. Cyclic electron flow occurs from the reducing side of PSI via plastohydroquinone and b₆f complex. This supports ATP synthesis but does not reduced NADP⁺.

Which one of the following combinations of the above statements is correct?

• A, B, and C

• A, C, and D

• A, B, and D

• B, C, and D

Ribulose bisphosphate carboxylase (Rubisco) catalyzes both carboxylation and oxygenation of ribulose-1, 5-bisphosphate. The latter reaction initiates a physiological process known as 'photorespiration'. The following are certain statements on photorespiration:

A. The active sites on Rubisco for carboxylation and oxygenation are different.

B. One of the steps in photorespiration is conversion of glycine to serine.

C. 50% of carbon lost in chloroplast due to oxygenation is recovered through photorespiration.

D. The pathway of photorespiration involves chloroplast, peroxisome and mitochondria.

Which one of the following combinations of above statements is correct?

• A and C

• A and D

• B and D

• C and D