PG Level Plant Physiology Questions and Answers (Set-3)

Following are certain statements regarding CO2 assimilation in higher plants:

(A). The action of aldolase enzyme during Calvin-Benson cycle produces fructose 1,6-bisphosphate.
(B). The conversion of glycine to serine takes place in mitochondria during C2 oxidative photosynthetic carbon cycle.
(C). During C4 carbon cycle, NAD-malic enzyme releases the CO2 from the 4-carbon acid, malate yielding a 3-carbon acid, pyruvate.
(D). Malic acid during crassulacean acid metabolism (CAM) is stored in mitochondria during dark and released back to cytosol during day.

Which one of the following combinations of above statements is correct? (CSIR_2015_II)

Many factors related to the role of abscisic acid (ABA) in contributing to drought, cold and salt resistance in plants are listed below:

(A). The transcription factors DREB1 and DREB2 bind to the cis-acting elements of the promoter of ABA-responsive genes in an ABA-dependent manner.
(B). ABA induces many genes such as LEA and RD29.
(C). ABA-responsive genes contain six- nucleotide ABRE elements in the promoter.
(D). Nine-nucleotide dehydration-responsive elements (DRE) are present in ABA- responsive genes.

Which one of the following combinations of the above statements is correct with respect to ABA? (CSIR_2015_II)

Examples of many factors that regulate plant height in response to gibberellic acid (GA) are listed below:

(A). Binding of a GA-bound repressor to the promoter of the DELLA domain- containing GRAS protein gene and blocking its expression.
(B). Binding of the GA-receptor complex to GRAS.
(C). Directing GRAS for ubiquitination and degradation by the 26S proteasome.
(D). Micro RNA directed down regulation of the GRAS protein expression.

Which one of the following combinations is correct? (CSIR_2015_II)

Ethylene is an important plant hormone that regulates several aspects of plant growth and development. Some statements are given below in relation to ethylene signalling pathways:

(A). Unbound ethylene receptors work as positive regulators of the response pathway.
(B). There are more than two ethylene receptors known to date.
(C). The carboxy-terminal half of the ethylene receptor, ETR1 (Ethylene-response-1), contains a domain homologous to histidine kinase catalytic domain.
(D). EIN2 (Ethylene-insensitive 2) encodes a transmembrane protein. The ein2 mutation promotes ethylene responses in both seedlings and adult Arabidopsis plants.

Which combination of the above statements is correct? (CSIR_2015_II)

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

(A). Pentose phosphate formed by photosyn- thesis 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 following combinations of above statements is correct? (CSIR_2016_I)

Which one of the following is NOT a phenotype of dark-grown seedlings that are etiolated? (CSIR_2017_II)

Which one of the following is the correct function of JAZ (JASMONATE ZIMDOMAIN) protein family, a key regulator of Jasmonic Acid (JA) signalling response? (CSIR_2017_II)

The plant hormone, Gibberellic Acid is generally NOT associated with (CSIR_2017_II)

Given below are some statements on secondary metabolites in plants. (CSIR_2017_II)

(A). Glucosinolates are synthesized by elongation in the length of side chains of their precursor amino acids.
(B). All terpenes produced in herbs and spices are sticky, oily liquids which reduces the palatability (edible value) of these plants.
(C). Cyanogenic glycosides are produced and stored in a toxic form in plants and are therefore more effective in defense against invading pathogens and herbivores.
(D). The defense molecules, alkaloids (or their precursors), are gathered from plants and used by some insects for their own protection against predators.

Which one of the following represents correct statements? (CSIR_2017_II)

Statoliths are present in which cells of the root?